bhopal institute of technology new lab manual

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BHOPAL INSTITUTE OF TECHNOLOGY, BHOPAL(M.P)

DEPARTMENT OF ELECTRICAL & ELECTRONICS ENGG.

LAB MANUALS

S.N. SUBJECT

CODE

SUBJECT NAME SEMESTER PAGE NO.

1 BE-104 BASIC ELECTRICAL &

ELECTRONICS ENNG.

I & II

2 EX-303 ELECTRICAL INSTRUMENTION III

3 EX-304 ELECTONICS DEVICIES & CIRCUIT-I III

4 EX-305 NETWORK ANALYSIS III

5 EX-306 JAVA III

6 EX-404 ELECTRO MECHANICAL ENERGY CONVERSION-

I

IV

7 EX-405 ELECTONICS DEVICIES& CIRCUIT-II IV

8 EX-406 SOFTWARE LAB MATLAB IV

9 EX-502 MICRO PROCESSOR & MICHRO CONTROLLERS V

10 EX-503 ELECTRICAL MACHINE-II V

11 EX-504 POWER ELECTRONICS DEVICES & CIRCUIT V

12 EX-505 POWER SYSTEM -1 V

13 EX-506 ELE.ENGG.SIMULATION V

14 EX-602 CONTROL SYSTEM VI

15 EX-603 SWITCHGEAR & PROTECTION VI

16 EX604 ELECTRONIC INSTRUMENTATION VI

17 EX-701 POWER SYSTEM-2 VII

18 EX-708 ELECTRICAL SIMULATION LAB VII

19 EX-801 COMP.ADD ELE.M/C DESIGEN VIII

20 EX-802 ELECTRICAL DRIVES VIII


BHOPAL INSTITUE OF TECHNOLOGY

LAB MANUAL

Version No. Basic Electronics and Electrical

Subject Basic Electronics and Electrical

Subject Code

EX-104

Scheme New

Class/Branch

I & II Semester / all

Author Mr. Kritarth Shrivastav

Institution Bhopal Institute of Technology


COURSE: BE104

Basic Electrical and Electronics Engineering

List of Experiment

1.Verifications of Thevenin‟s Superposition theorem.

2.Study of Transformer, name plate rating,Determination of ratio

and polarity

3.Determination of equivalent circuit parameters of a single phase

transformer by O.C. And S.C. tests and estimation of voltage

regulation and efficiency at various loading conditions and

verification by load test.

4. Separation of resistance and inductance of choke coil.


5.Measurement of various line & phase quantities for a

3-phase circuit.

6. Identification of different Electronics

components.

7.Observing input and output waveforms of

rectifiers .

8.Verification of truth table for various gates.

9. To study the transistor characteristics of CB,

CE , CC.

EXPERIMENT NO. 1

AIM: - To verify Thevenin‟s theorem.

APPARATUS REQUIRED: - Experimental Kit, Connecting Probes.

THEORY: - Sometimes it is necessary to find a particular branch current in a circuit as the resistance

of that branch is varied while all other resistances, voltage sources and the current sources remain the

same.

This theorem states that,” Any two terminal network containing a number of

e.m.f. sources and resistances can be replaced by an equivalent series circuit having a voltage source VTH

in series with a resistance RTH.”

Where, VTH = Open circuit voltage between two terminals.

RTH = The resistance between two terminals of the circuit obtained by looking in at the terminals

with removed and voltage sources replaced by their internal resistances, if any.

The load current is given by:

IL =


Fig no.1

Fig no.2

Fig no.3


Fig no.4

PROCEDURE:-

1. Connect the circuit as shown in fig 1. Measure the values of load current at different load

resistance. It is IL1, IL2 & IL3.

2. Connect the circuit as shown in fig. 2. Disconnect the load resistor (RL) from output terminals

and measure the open circuit voltage (VTH) by connecting analog voltmeter. Open circuit voltage

will appear across 100Ω resistor:

V =

3. For measurement of Thevenin‟s resistance across open circuit terminals X-Y, disconnect the

12V voltage source and short the voltage source open circuit terminals A-B as shown in fig. 3.

Connect the digital multimeter across terminal X-Y. Find the value of RTH.

Now measure the resistance across X and Y.

RTH

4.Now, above circuit between X & Y can be replaced by Thevenin‟s equivalent circuit as

shown in fig 4.

VTH = 1.8 V, RTH = 173.4 Ω


For RL = 25 Ω

IL1 = = ……….mA

For RL = 50 Ω

IL1 = = ……….mA

For RL = 75 Ω

IL1 = = ……….mA

5. Compare the calculated and measured values.

OBSERVATION TABLE:-

S.NO. EQUIVALENT

VALUES MEASURED VALUES CALCULATED VALUES

1. RTH,VTH

2. RTH,VTH

3. RTH,VTH

RESULT:

PRECAUTIONS:

The positive & negative terminals of the power supply should not be connected together.

Supply for the experimental kit should be switched ON only after the connections are verified.

Avoid parallax error.

Check the polarities of the meter before the observations are noted down.


EXPERIMENT NO. 01

AIM: To verify Superposition theorem.

APPARATUS: Experimental Kit, Connecting Probes.

THEORY: When there is only one source of e.m.f. or only one current source, then it is very easy to

calculate the current or the voltage. But in a complex circuit where there are a number of sources acting

simultaneously, then it is very difficult to calculate the current or the voltages. In these situations

superposition theorem is used.

The theorem states that, “If a number of current or voltage sources are acting simultaneously

in a linear network, the resultant current in any branch is the algebraic sum of the currents that would be

produced in it, when each source acts alone replacing all other sources by their internal resistances.”

CIRCUIT DIAGRAM:

Fig. 01


Fig no.2

Fig no.3

PROCEDURE:

1. Connect the circuit as shown in fig 1. Measure the current i1, i2 and i3.

2. Connect the circuit as shown in fig. 2. Consider only one voltage source at a time, first 12V.

Short the second 5V source. Measure the current i1‟, i2‟ and i3‟ (One ammeter is connected at a

time, other ammeter is shorted).

3. Connect the circuit as shown in fig. 3. Consider only 5V voltage source. Short the second 12V

source. Measure the current i1‟‟, i2‟‟ and i3‟‟.

4. Calculate the value of i1‟ , i2‟ , i3‟, i1‟‟, i2‟‟ and i3‟‟.

5. Compare the calculated and measured values.


OBSERVATION TABLE:

Sr. No. Measured Value Calculated Value

i1’

i2’

i3’

i1”

i2”

i3”

i1

i2

i3

CALCULATIONS:

Consider only one voltage source at a time, first 12V.

RT = 50 + = 50 + 8.33 = 58.33 Ω

ITH =

IT = i1’

i3’ =

i2’ = i1’ - i3’ =……….

Therefore,

i1’ =……….

i2’=……….

i3’=……….

Now, considering 5V voltage source only:

RT = 50 + = 50 + 8.33 = 58.33 Ω


ITH =

IT = i3’’

i3’ =

i1’ = i3’ - i2’ =……….

Therefore,

i1’ =……….

i2’=……….

i3’=……….

According to superposition theorem,

Current through resistance R1 = i1‟ - i1‟‟ =……….

Current through resistance R2 = i2‟ – i2‟‟ =……….

Current through resistance R3 = i3‟ – i3‟‟ =……….

RESULT:

PRECAUTIONS:

The positive & negative terminals of the power supply should not be connected together.

Supply for the experimental kit should be switched ON only after the connections are verified.



EXPERIMENT -2

OBJECTIVE:- Study of transformer name plate rating.

Apparatus Required:-Transformer.

Theory:- The transformer specifications give the rating and performance expectations of the


transformer. These are broadly as below:

1.KVA rating 2. Rated voltage 3. Number of phases(1-Փ or 3- Փ). 4. Rated frequency. 5. Connections(-

------). 6. Tappings if any 7. Type of core (core or shell). 8.Type (power or distribution). 9. Ambient

temperature (generally average 40 0 c) 10. type of cooling[(a) cooling medium -air ,oil or water (b)

circulation type -natural or forced (c) simple or mixed cooling].11. Temperature rise above ambient in 0c

depending upon the class of winding insulation.12. Voltage regulation[(a) percent or pu (c) reactance -

percent or per unit] 13. No load Current in amperes or percent of rated current at rated voltage and rated

frequency.14. Efficiency -in percent or per unit

at full load,1/2 load,3/4 load at unity pf or .8 pf.

The specifications items and limitations are laid down by the following IS

specifications:

IS : 1180-1964: specifications for outdoor type three phase distribution

transformer upto and including 100 Kva and 11 kv.

IS :2026-(PART I,II,III.IV 1977: Specificatins for power transformers beyond

Kva.

(a) Outdoor type distribution transformers (IS : 1180-1964)

According to this the standard ratings for distribution type transformers are

16,25,40,50,63,80and Kva.

The no load voltage ratios are 3300/433v,6600/433v and 1100/433v.

The tapping shall be provided on hv side and shall be in 5 steps.

The ranges shall be + 2.5 and +5%.Off load tap changers are used.

CONNECTIONS :------- with neutral brought out to a seperate insulated terminal.

Cooling is by low viscocity transformer oil.

Conservator tank is provided on transformer of rating 50 Kva or above.

LIMITS OF TEMPERATURE RISE : The following temperature rises shall be permitted over the

ambient temperature of 450c.

Temperature rise in winding mmeasured by resistance method -550c.

Temperature rise in oil measured by thermometer in the top oil-450c.

The above temperature rises are for ON, OB AND OW type cooling.

IMPEDENCE: The percentage impedence at 750c is 4.5% subject to the tolerence

limits of +10%.

Power transformers(IS 2026-1962) The standard Kva ratings for 3-Φ transformers are

25,40,63,100,125,160,200,250,315,400,500,630,800,1000,1250,1600,2000,2500,3125,4000,6300

,8000,10000,12500,16000,20000,25000,31500,40000,50000,63

000,and 80000 Kva.

The standard ratings for 1-phase transformers are 1,2,5,10,16 and 25 KVA.

Above 25 kva ,the standard rating for single phase transformers shall be one-third of

the value given for 3-phase transformers.

TAPPINGS : The standard tapping ranges are +2 1/2% and +5%.

Tap changing is carried out by means of an externally operated off-circuit

switch capable of being locked in positions.

If required ,the transformers may be equipped with on-load tap -changer.


EXPERIMENT NO.2

OBJECTIVE: - To find the polarity of primary and secondary winding on a single phase

Transformer.

PRE-REQUISITS:- (1.) Basic knowledge about Xmers.

(2.) Concept of primary & secondary winding.

(3.) Concept of polarity.


DESCRIPTION OF APPARATUS:-

S.NO NAME TYPE RANGE QTY.

1. VOLTMETER M.I. 0-300 02

2. VOLTMETER M.I. 0-600 01

3. TRANSFORMER - 2KVA 01

4. VARIAC 1ɸ 260V 01

5. CONNECTING WIRE - - -

UNDERLYING CONCEPTS:-

POLARITY: - Each of the terminal of primary as well as secondary windings of a transformer is

alternately positive and negative with respect to each other . It is essential to know the relative polarities

at any instant of the primary and secondary terminals for making correct connections under the

following type of the transformer.

(I) When two single phase transformer are to be connected in parallel to share the total load on the

system

(II) For connecting the 3 single phase transformer to form a 3 phase bank with proper connections of

primary and secondary windings.

Referring fig , if at any instant , the induced emf E1 in the primary acts from the terminals marked A2 to

A1 the induced emf E2 in the secondary winding will act from a2 to a1 i.e. if at any instant A1 is

positive and A2 negative with respect to the applied voltage V1 across the primary winding then the

terminal voltage V2 across the secondary winding will be positive at a1 and negative at a2 .

If the two winding are connected by joining A1 to A2 as shows in fig, and an alternating voltage V1

applied across the primary, then the marking are corrected if the voltage V3 is less than V1. Such a

polarity is generally termed as. Subtractive polarity, in which the induced emfs in the primary and

secondary winding are subtractive. The standard practice is to have subtractive polarity for transformer

connections, because it reduce the voltage stress between the adjacent loads. In case V3 is grater than V1,

the emfs induced in the primary and secondary windings have an additive polarity.


V2 MI

(0 - 300)V

1- ø, 260 V

50 Hz

AC Supply

V3

MI

(0 - 600)V

V1 MI

(0 - 300)V

P1

P2

S1

S2

POLARITY TEST

PROCEDURE :- a) Polarity test:-

Connect the circuit as per fig.

Switch on single phase ac supply.


Record the voltages V1, V2 and V3. It is advisable to use a single voltmeter with probes to

measure these three voltages. In case V3 <V1, the polarity is subtractive.

Repeat step 3, after connecting the terminals A1 and A2. The transformer should be disconnected

before making. This change in this case V3>V1, which indicates additive polarity.

Switch of the ac supply.

As V3 > V1 Additive Polarity

As V3 < V1 Subtractive Polarity

Observations: - May be tabulated as follows:-

S.No. (a). additive polarity S.No. (b).Subtractive Polarity

V1 V2 V3 V1 V2 V3

RATIO TEST

OBJECTIVES: - To measure voltage ratio of primary and secondary windings

PRE-REQUISITS:-

1) Basic knowledge of transformers.

2) Concept of voltage ratio.

DESCRIPTION OF APPARATUS:-


S.No. NAME TYPE RANGE QTY.

1. VOLTMETER MI. 0-300V 02

2. TRANSFORMER 1Ø 1 KVA 01

3. VARIAC 1Ø 0-270V 01

4. CONNECTING WIRE - - -

UNDERLYING CONCEPTS:-

Voltage Ratio:-

The induced emf per phase in the primary and secondary winding of a transformer is given by,

Induced emf in primary, E1 = 4.44 f Φm T1.

Induced emf in secondary, E2=4.44 f Φm T2

However, E1 = V1 and E2 = V2

Hence, the voltage ratio, V2/V1 = T2/T1

Circuit Diagram -: Given in fig


V2 MI

(0 - 300)V

1- ø, 260 V

50 Hz

AC Supply

V1 MI

(0 - 300)V

86.6%

50%

28.8%

RATIO TEST

Voltage Ratio test:-

Procedure:-

1. Connect the circuit as per fig.

2. Switch on ac supply.

3. Record the voltage V1 across the primary and V2 across various tapping of the secondary.

It will be preferred, if all the voltage are measured by the same voltmeter.

4. Switch off the ac supply.

Observation Table:-

SNO. V1 V2 V1/V2


EXPERIMENT No- 03

AIM: - To Perform Open Circuit and Short Circuit test on transformer.

APPARATUS REQUIRED: -

Sr. No. NAME RANGE QUANTITY

1 Ammeter 0-5AMP 1

2 Ammeter 0-1 AMP 1

3 Voltmeter 0-300V 1

4 Autotransformer 0-270V 1

5 Wattmeter 0-375Watt 1

6 Single Phase Transformer 2KVA,220V,50Hz 1

THEORY: - In various experiments, transformer is being operated normally under one of the

following condition.

1. NO LOAD OR OPEN CIRCUIT: - Generally high voltage Winding is open circuited is open circuited.

Such a test is performed at rated voltage applied to low voltage winding no load test is performed to

find out the no load / core losses.

2. LOAD:-Load on the secondary winding varied in steps to ascertain behaviour of transformer under

loaded conditions.

3. SHORT CIRCUIT: - Low voltage winding is generally short circuited and quite low Voltage applied to

high voltage winding. Such a test is normally performed under full Load current condition. This test is

performed to find out full load losses.

PROCEDURE:-

(a). Open circuited test :-

1 Connect the circuit as per the circuit diagram.

2 Ensure that the setting of the variac is at now output voltage.


3 Switch on the supply and adjust rated voltage across the transformer circuit .

4 Record no load current, voltage applied and no load power, corresponding to the rated

voltage of the transformer winding.

5 Switch off the AC supply.

(b)Short circuit test :-

6 Connect the instruments as per the circuit diagram.

7 Adjust the setting of the variac so that the output voltage is zero.

8 Switch on the AC supply to the circuit.

9 Increase the voltage applied slowly till the current in the winding of the transformer is

full load rated value.

10 Record short circuit current, corresponding applied voltage and power with full load

current under short circuit condition.

11 Switch off the AC supply.

A

V

M L

C V

L.V. H.V.

(0-150/300)W(0-1/2)A

(0 - 300)V1- ø, 260 V

50Hz

AC Supply

OPEN CIRCUIT TEST


A

V

M L

C V

L.V. H.V.

(0 - 375)W

(0 - 5)A

(0 - 300)V1- ø, 260 V

50 Hz

AC Supply

SHORT CIRCUIT TEST

OBSERVATION TABLE:-

S.No Open circuit test Short circuit test

Vo Io Wo Vsc Isc Wsc

1

2


CALCUATIONS:- For open circuit test

Wo =Vo Io CosØo

CosØo = Wo / Vo Io

Io CosØo = Ic or Iw

Io sin ϕo = Iµ or Im

(Io)² = (Ic2

+ Iµ2)

Ro = Vo / Ic

Xo = Vo / Im

For short circuit test

Wsc = Isc2 Req.

Req. = Wsc / Isc2

Zeq. = Vsc / Isc

(Xeq) ² = Z2 – R

2

Result: -

Precaution:-

1. Make the connection correct & according to the circuit diagram.

2. All connection should be made with power supply off.

3. Signal should not be applied to the input while the instrument power supply on.


EXPERIMENT NO: 04

Measurement of power in three phase circuits

OBJECTIVE: - To measure power by a 3 phase inductive load using two wattmeters

PRE. REQUISITES :- (1) Knowledge of measurement of 3-Ø power by various methods

(2) Principle of working of wattmeter.

INSTRUMENTS REQUIRED:-

UNDER

LYING

CONCE

PT

Power

consumed

by a 3 phase balanced or unbalanced load (star or delta connected) Can be measured by using two

wattmeters properly connected in the load circuit . The current coils of the wattmeters are connected in

series with the load lines in any two lines, whereas the two pressure coils are connected between these

lines and the third line as shown in fig.

The phasor diagram of this circuit ,assuming balanced lagging load has been shown in fig. As such,rms

Sr. No. Name Type Range Quantity

1 Wattmeter Dynamometer 5/10A,200/400V 2

2 Ammeter MI 0-10A 1

3 Voltmeter MI 0-600 1

4 3-Phase Variac MI 400/0-400V,15 A 1

5 3-Phase inductive load Inductive -- 1


values of currents Ir,Iy,Ib are taken equal in magnitude and lagging by an angle ǿ with respect to its own

phase voltage .Similarly, rms values of phase voltages are also equal in magnitude but displaced by

120.The Phase sequence has been assumed as R,Y,B.Based in the phasor diagram, power consumed and

the power factor of load can be calculated from the readings of two wattmeters W1 and W2 as explained

below.

Power factor of the load

W1-W2 = VL IL Cos (30-Ø ) - VL IL Cos(30+Ø )

Tan Ø = √3 (W1-W2)/(W1+W2)

Ø = Tanˉ¹√3 (W1-W2)/(W1+W2)

Cos Ø = Cos [Tanˉ¹√3 (W1-W2)/(W1+W2)]

PROCEDURE:

Connect the circuit as per fig.

Ensure that the output voltage of 3 phase Variac is at zero or low.

Switch on the 3 phase ac supply.

Apply a certain voltage to the circuit and note down the regarding of all the meter connected in

the circuit.

Repeat step 4 for various values of applied load till the rated supply voltage.

Reduce the voltage applied to 3 phase load and then switch off the supply.



LAB MANUAL

Version no

Subject ELECTRONICS INSTRUMENTATION

Subject code EX/

Scheme NEW

Class/Branch VI SEMESTER/EX

Author Nirupa chaturbedi

Institution BHOPAL INSTITUTE OF TECHNOLOGY

LIST OF EXPERIMENTS

Experiment

No

NAME OF EXPERIMENT

1 (a) To Study of Input-Output characteristics of LVDT.

(b) Determination of sensitivity of LVDT.

2 (a) Study of Strain measurement using Strain gauges and

cantilever assembly.

(b) Determining sensitivity Strain Gauge.

3 To measure the value of unknown Resistance with the help of

wheat stone bridge.

4 To measure the value of unknown inductance with the help of

Maxwell's inductance bridge .

5 To measure the value of unknown capacitance with the help of

schering bridge .

6 To study the characteristics of photo voltaic cell.

7 To study and observe the characteristic of PIN Photo diode .


8 To study the characteristic of platinum RTD .

9 To study the operation of Analog to Digital converter .

10 To study the operation of digital to Analog converter .

Experiment : 1(a) Objective :

Determination of sensitivity of LVDT

Theory :

Sensitivity : The ratio of the change in LVDT output to a change in the value of the

measure and (displacement). Sensitivity is the smallest change in displacement,

which

LVDT is able to detect. The output of LVDT is an alternating signal which is

rectified

and filtered to give DC output (Signal conditioner output). The DC output is

proportional to amplitude of alternating signal of LVDT.

Sensitivity S = AC output / Displacement (Vpp/ mm) OR

= DC output / displacement (Vdc/mm)

Procedure :

1. Switch ON the trainer.

2. Make micrometer to read 10 mm.

3. Note the reading of micrometer.


4. Measure the differential voltage between Test Point TP6 and TP7 with multi-

meter in mV range.


6. Repeat step 4.

(Differential voltage for 10 mm - Differential

voltage for 9 mm)

7. Calculate S = (10 mm - 9 mm)

= ……………. mV/mm

Expe

riment 1(b) Objective :

Study of Input-Output characteristics of LVDT

Apparatus Required:

LVDT kit

Multimeter

Connecting probes

Theory:

Linear variable differential transformers (LVDT) are used to measure displacement.

LVDTs operate on the principle of a transformer. As shown in figure 4, an LVDT

consists of a coil assembly and a core. The coil assembly is typically mounted to a

stationary form, while the core is secured to the object whose position is being

measured. The coil assembly consists of three coils of wire wound on the hollow

form. A core of permeable material can slide freely through the center of the form.

The inner coil is the primary, which is excited by an AC source as shown. Magnetic

flux produced by the primary is coupled to the two secondary coils, inducing an AC

voltage in each coil.

LVDT Measurement :


LVDT measures displacement by associating a specific signal value for any given

position of the core. This association of a signal value to a position occurs

through

electromagnetic coupling of an AC excitation signal on the primary winding to the

core and back to the secondary windings. The position of the core determines how

tightly the signal of the primary coil is coupled to each of the secondary coils.

The

two secondary coils are series-opposed, which means wound in series but in opposite

directions. This results in the two signals on each secondary being 180 deg out of

phase. Therefore phase of the output signal determines direction and its amplitude,

distance.

Displac

ing the

core to

the

left

causes

the first secondary to be more strongly coupled to the primary than the second

secondary. The resulting higher voltage of the first secondary in relation to the

second secondary causes an output voltage that is in phase with the primary voltage.

Procedure :


2. Make micrometer to read 10 mm .

3. Display will indicate 00.0. This is the position when core is at centre i.e

equal flux linking to both the secondary.

5. Rotating thimble again clockwise by 0.1mm. Reading will be taken after each

0.1 mm rotation until micrometer read 0 mm. This is positive end. At this point

secondary I have highest voltage and secondary II has lowest voltage.

6. Rotate thimble anticlockwise so that micrometer read 10 mm.

7. Rotate thimble anti clockwise so that micrometer read 10.1 mm. It will move

core 0.1 mm outside the LVDT and simultaneously observe reading on display.

It will indicate displacement from 10 mm position in negative direction. The

reading will be negative. It indicates that secondary II is at higher voltage

than

secondary I.


8.take reading of voltage generated in coil by connecting multimeter on output point

of LVDT kit.

9. Plot the graph between displacement (mm) indicated by micrometer and Display

reading (mm).The graph will be linear .

Observation Table:

S.no Displacement in micrometer Display displacement(mm) Generated voltage (mv)


Experiment 2(a)

Objective :

Determining sensitivity Strain Gauge

Theory :

Strain Gauge :

If a metal conductor is stretched or compressed, its resistance changes on account

of

the fact that both the length and diameter of the conductor change. There is also a

change in the value of resistivity of the conductor when it is strained and this

property

is called piezoresistive effect. This is the principle of strain gauge. Strain gauge


is a

device the electrical resistance of which varies in proportion to the amount of

strain in

the device. The most widely used gauge is the bonded metallic strain gauge.

A strain gauge of length L, area A, and diameter D when unstrained has resistance

R = (ρL)/ A

When a gauge is subjected to positive strain, its length increases while its area of

cross section decreases, resistance of gauge increases with positive strain.

lateral strain − ∂D / D

ε = strain = ∆L/L

∆R / R

Gauge Factor = ∆L / L

Sensitivity :

The ratio of the change in auxillary output to a change in the value of the

measurand

(strain). Sensitivity is the smallest change in strain, which the trainer is able to

detect.

Strain is directly proportional to weight.

Auxillary Output

Sensitivity S = Weight mV /gm

Procedure :

1. Switch ‘On’ the trainer.

2. Measure the auxillary output.

3. Adjust Offset Null Adjust preset slowly to get 0 mV at auxillary output

terminal.

4. Place weight of 5 gm on cantilever and measure the auxillary output voltage by

multimeter in 200 mV range.

5. Repeat the above step by placing the weights of 10gm, 20 gms etc.

6. Calculate :Auxillary output for above specified weights.

Weight

S= ……………. mV/gm

7.Compare value of sensitivity for different weights.


Experiment :2(b)

Objective :

Study of Strain measurement using strain gauges and cantilever assembly

Apparatus Required :

Strain gauge Kit

Connecting Probes

Theory:

Strain is the amount of deformation of a body due to an applied force. More

specifically, strain (ε) is defined as the fractional change in length, as shown

below.

∆L

ε= L

Strain can be positive (tensile) or negative (compressive). Although dimensionless,

strain is sometimes expressed in units such as in/in or mm/mm. In practice, the

magnitude of measured strain is very small. Therefore, strain is often expressed as

micro strain (µ-strain), which is ε x 10 -6.

Types of Strain gauges :

1. Unbonded metal strain gauges.

2. Bonded metal wire strain gauges.

3. Bonded metal foil strain gauges.

4. Vacuum deposited thin metal film strain gauges.

5. Sputter deposited thin film metal strain gauges.

Procedure :


2. Observe reading of the display. It should be 000.

6. If the display reading is not 000 then adjust offset null.

7. Take reading of strain directly from display board .


8.

Observation Table:

S.no Weight in gm Strain

Result:


EXPERIMENT NO : 03

AIM :-To measure the value of unknown inductance with the help of Maxwell's

inductance bridge


Analog board

Dc power supply

function generator

2mm patch cord

Digital multimeter

Circuit

Diagram:

Theory :

This is the simplest method of comparing two inductance and to determine the values

off unknown inductance.Its first arm consist of a non inductive resistance R1 second

arm consist of a standard in in series with the noninductive resistance R3 is used

for resistance balance control third arm consist of an unknown inductors with

internal resistance Rx The balance can be obtained by varying resistance R2 of third

arm


L1 = inductor with unknown inductance

Rx= internal resistance

L3= standard inductor

R1,R3= non inductive resistance

At balance

Z1 Zx=Z2 Z3

the value of Lx can be calculated by the formula

Lx =L3R2/R1

Where Lis the value of unknown inductor and R is internal resistaance

PROCEDURE :-

(b)Connect external power supply

(c)Connect function generator probe in between Vin terminals

(d)Make connection as shown in figure

(e)Set 5Vpp,1 Khz input sinusoidal signal of function generator

(f)Rotate the potentiometer R2 to find null or minimum sound is generated

(g)Switch off the power supply and function generator

(h)Take the reading of potentiometer resistance R2 between test points TP2 and

TP3

(i)calculate the value of inductance Lxi and Rxi by there formula

(j)Take the reading of unknown internal resistance Rx1 at socket a and test

point Tp2

(k)Repeat the above steps for different values of Lx and Rx

OBSERVATION TABLE :

S NO RI R2 L3 LX=L3R2/R1 Rx=R2R3/R1

1

2

3

CALCULATION :

Measured value of R2 is .............ohm

Now measure the value of Lx by the formula

LX=L3R2/R1

Measured value of resistance Rx by the multimeter between socket .........ohm


Now measure the values of Rx by the formula

Rx=R2R3/R1

Result :

The Inductance for Lx is measured to be =.............micro henry

The internal Resistance is =.................ohm

EXPERIMENT NO :04

Aim:- To measure the value of unknown capacitance with the help of schering

bridge

Apparatus Required :-

Analog board

DC power supply

Function generator

2mm patch cord

Digital multimeter

Theory :-

This bridge is the simplest method of comparing Two capacitance and to determine

unknown capacitance In first arm Zx consist of an unknown capacitor cx in series

with the resistance Rx and second arm consist of capacitor c3 and third arm consist

of variable resistance R2 and forth arm consist of a parallel combinaation of

resistance R 1 and capacitor c1 The balance can be obtained by varying the resistance

R2of third arm

At balance

Z1Zx=Z2Z3

The value of Rx can be calculated by formula

RX =R2C1/C3 The value of Cx can be calculated by the formula

Cx =R1C3/R2

Procedure :

Connect external powerr supply

connect functioon generator probe in between vin termminals

Make connectioon as shown in figure

Set 5Vpp,1 Khz input sinusoidal signal of function generatorr

Rotate the potentiometer R2 to find null or minimum sound is


generated

Switch off the power supply and function generatorr

Take the readingg of potentiometer resistance R2 between test

points TP2 and TP3

calculate the value of capacitance Cxi and Rxi by there formula

Take the reading of unknown internal resistance Rx1 at socket a

and test point Tp2

Repeat the above steps for different values of Cx and Rx

Observaation table :-

S no R1 C1 C R RX=R2C1/C3 CX= R1C3/R2

1

2

3

Measured value of R2 is ...............ohm /k ohm

Now measure the value of Cx by the formula

CX= R1C3/R2 Now measure the value of Rx by the formula

RX=R2C1/C3 Result :-

The capacitance of capacitor CX= ...........micro farad

The effective resistance Rx= ...................ohm /K ohm

EXPERIMENT NO : 05

AIM:-To study the characteristics of photo voltaic cell

APPARATUS REQUIRED:-Experiment kit,connecting probes,digital multimeter.

Circuit Diagram:

THEORY :-

The photo voltaic cell is a two layer device,It generate a voltage by electron/hole

pair production when the junction is exposed to light.these diffuse across the


junction to set up voltage. A current will flow if a resistance is placed across the

terminal optimized for energy production are often called solar cells This is an

important class of photo detectors. They generate a voltage proportional to EM

radiation intensity. They are called photo voltaic cells because of their voltage

generating characteristic when light falls on them. They in fact convert the EM

energy into electrical energy. They are active transducers ie they do not need an

external source to power them instead they generating voltage .

The cell is a diode constructing a pn junction between appropriately doped

semiconductors Photons striking cell pass through the thin p doped under layer

and are absorbed by electrons in lower layer causing a difference of potential to

develop across the junction. All photo voltaic cell have low but finite internal

resistance .When connected in circuit having some load resistance

photo voltaic the cell voltage is reduced some what from rated value .

The photo voltaic cell can operate satisfactorily in temperature range of 100 to

125 c The temp. changes have little effect on short circuited current but affect the

open circuited voltage considerably .The main advantage of the photo voltaic cell

as name implies are its stability to generate a voltage without any form of bias

and its extremely fast responses ,This means that it can be used as an energy

converter directlY

CHARACTERISTIC:-


PROCEDURE:-

Connect the circuit as shown in figure

The socket C of wire wound pot to +12 v

The socket A of Wire wound pot to 0v

The socket B of wire wound pot to input of powerr amplifier

The out put of power amplifier to input of Lamp filament

The other input of filament lamp to +ve input of Moving coil meterr '

The -ve input of moving coil meter to 0 v

Output of photo voltaic cell to 0v through a digital multimeter connected as

an ammeter at 2 mA range to measure short circuit current of photo voltaic

cell

switch ON the power supply & set the 10 K ohm wire wound pot to minimum zero

output voltage from power amplifier

Place the opaque box over the plastic enclosure to exclude all the ambient

light Take reading of photo voltaic cell short circuit output current as

indicated on digital multimeter as lamp voltage is increased in 1 v steps

record the result in below table

OBSERVATION TABLE:-

Lamp filament

voltage

0 1 2 3 4 5 6 7 8 9 10

Short circuit

output current

(Micro A)

Open circuit

output voltage

Procedure:

3) Switch off the power supply &set the digital multimeter as voltmeter


at 2/20 v dc range to read the open circuit output voltage

4) Switch on thee power supply and take the reading adding result to above table

5) switch off the power supply

6) Plot the graphs off photo voltaic cell short circuit current & open circuit

voltage against lamp filament voltage

RESULT :-characteristic of photo voltaic cell is plotted.

EXPERIMENT NO :06

AIM:-To study and observe the characteristic of PIN Photo diode .

Apparatus required :- Experiment kit,connecting probes

DIAGRAM:-


Theory :-

PIN photodiode differs from a standard PN photodiode by having layer of intrinsic

silicon.The intrinsic (I) region between normal P&N junction.The main improvement

of introuduction of I region is reducing capacitance of junction resulting

improvement of introuduction of I region is reducing capacitance of junction

resulting in fast response time .

When photodiode is reverse biased The reverse saturation current is depend

upon the intensity of incident light The photodiode Vs light relation ship is

linear over wide range in order to maintaine linearity the bias volatage

should be kept constant The output resistance of photodiode is very high of

the order of tens of mega ohms the DC resistance is the diode leakage

resistance and that too is very high This DC resistance depends upon the light

intensity.

CHARACTERISTIC:-


PROCEDURE:-

5. Connect the circuit as shown in the figure

socket c of wire wound pot to +12 v

socket A of wire wound pot to input of power amplifier

socket B of wire wound pot to input of power amplifier

Output of power amplifier to input of filament lamp

Other input of filament lamp to + ve input of moving coil meter

Connect -ve input of moving coil meter to 0v

Output of PIN photot diode to input of current amplifier this is used

to measure the current output of PIN photodiode

Output of current amplifier to input of DC amplifier

connect a digital multimeter as voltmeter on 20v dc range betwen output of DC

amplifier and 0v to measure the output voltage of DC amplifier

Place opaque box over the plastic enclosure to enclosure to exclude all ambient

light

Switch on the power supply and set the 10 k ohm wire wound pot.To minimum input at

DC amplifier

Take reading of Amplifier output voltage on digital multimeter as lamp voltage is

increased in 1v steps record the result in below table

Lamp filament

voltagee (v)

0 1 2 3 4 5 6 7 8 9

PIN Photodiode DC

amplifier output

voltage (v)


PIN Photodiode

Buffer output

voltage (V)

Switch off the power supply

Change the current Amplifier to Buffer to measure output of PIN photo diode Take the

reading of PIN Photodiode output voltage as the lamp voltage is increased in 1v

steps record the result in table 4 remember to adjust the offset of DC amplifier is

giving zero output for zero input

Plot the graph between PIN photodiode current amplifier output voltage,buffer

amplifier output voltage &Lamp filament voltage.It should resemble the one given

below

Result :

chaaracterisic of PIN photodiode is studied


EXPERIMENT NO :07

Aim :-

To study the characteristic of platinum RTD

Apparatus required :- Experiment kit connecting probes digital multimeter

Theory:-

The variation in resistance of metal with variation in temperature is the basis of

of temprature measuremet in platinum rtd The metal generally used is platinum or

tungsten Platinum is especially suited for this purpose.as it can show limited

susceptibility to contaminaation all metal produce a positive change in resistance

with temprature This of course is the main function of an RTD.This implies that a

metal with high value off resistance should be used for RTD the requirment of the

conductor material to be used in RTD .The change in resistance of material per

unit change in temperature should be as large as possible .The material should

have high value of resistance so that minimum volume of material is used for the

construction of RTD .The resistance of material should have continoous and stable

relation ship with temperatu.Platinum or tungsten wire is wound on a former to give

a resistance in range of 10 K ohm depending upon application

Procedure :-

connect the circuit as shown in figure

The socket 'c'of slide potentiometer to +5v

The socket 'b' of slide potentiometer to output of platinum RTD connect digital

multimeter as

voltameter on 200 mv orr 2v DC range in between output of platinum RTD &ground

Set the 10 K slider resistance midway

Switch on the instrument check the output of IC temperature sensor for ambient

temperature by temperorily connecting DMM in 20 v DC range and find out the

resissstance in ohm for this particular temperaturee

Say for example ambient is 250c then platinum RTD reading as per chart is 109.73

switch on the power supply adjust the slider control of the 10 K ohm resistance to

the voltage drop across the platinum RTD is 109mv as indicatied by DMM This


calliberate the platinum RTD for an ambient temperature of 250c since the

resistance at 250c will be 109 ohms Note that the voltage reading across the RTD in

mV is the same as the RTD resistance jin ohms,since current flowing must be

0.109/109=1 mA

Connect the +12V supply to Heater element input and note the values of the voltage

across the RTD with the voltmeter to its 200mV or 2 Vrange (this representing the

RTD resistance ) and the output voltage from the IC temperature sensor with the

voltmeter set to its 20 v range (this representing the temperature of the RTD )

after each minute given in below table

Time (minutes)

0 1 2 3 4 5 6 7 8 9

RTD

Temperaaature

RTD resistance (OHM

)

Switch of the power supply and disconnect heater element supply (+12)

Convert RTD temperature into 0c & add in above table

Plot the graph of RTD resistance in ohm against temperature in 0c .It should

resemble the one given below

Temperature Vs resistance Table

0 100.00 30 111.67

1 100.39 31 112.06

2 100.78 32 112.44

3 101.17 33 112.83

4 101.56 34 113.22

5 101.95 35 113.61

6 102.34 36 114.99

7 102.73 37 114..77

8 103.12 38 115.15

9 103.51 39 115.15

10 103.90 40 115.54

11 104.29 41 115.93

12 104.68 42 116.31

13 105.07 43 116.70

14 105.46 44 117.08

15 105.85 45 117.47


16 106.23 46 117.86

17 106.62 47 118.24

18 107.01 48 118.63

19 107.40 49 119.01

20 107.79 50 119.40

21 108.18 51 119.78

22 108.57 52 120.17

23 108.57 53 120.55

24 109.34 54 120.94

25 109.73 55 121.32

26 110.12 56 121.70

27 110.51 57 122.09

28 110.89 58 122.47

29 111.28 59 122.86

60 123.24

EXPERIMENT NO : 08

Aim :-To study the operation of analog to digital converter

Apparatus required :-Experiment kit,connecting probes,oscilloscope

Theory :-

The analog to digital conversion is a logical process that requires conceptually

two steps the quantizing and the coding. Quantization is the process that performs

the transformation of continuous signal in a set of discrete level soon afterward

we combine through the coding each discrete levels with a digital word.The digital

to analog converter performs the conversion in n steps where n is the converter

settlement in bits .The working principle of this converter is analogous to that of

weighing an object on laboratory balance using standard weights as reference

according to the binary sequence ¼,1/8,1/16............1/n Kilograms to perform

accurately we start with largest weight and go on decreasing order to one of

smallest value.

PROCEDURE :-

Connect the power supply to the trainer


Make the connection as shown in the figure

Connect the dc supply to the Vi of the converter

Keep the DC pot in counter clock wise position

Place the reset/count switch in reset position

Switch ON the power supply Keep the DC pot at mid position

To start conversion place the switch in count position the LED lit

accroadding to binary sequence

When the signal from the digital to analog converter goes over the input

signal the counter stops and LEDs show the binary conversion

Vary the DC pot and observe thee corresponding digital output. The converter

will follow the changes in analog signal without resetting the converter in

upward direction because the counter is configured as up counter only but to

observe the converted output when the input is decreased you have to reset

the converter

Observe on the oscilloscope the typical steps signal at the D/A output

Observe input voltage using digital multimeter and observe output LED

Repeat the test with the different values of input signal.

Result :- Analog to digital conversion is studied .

EXPERIMENT NO : 09

AIM :-

To study and observe the functional verification of a weighted resistor

digital to analog converter

APPARATUS REQUIRED:-Experiment kit, Connecting probes , Digital multimeter

THEORY:-

The simplest digital to analog converter is obtained by means of a summing

circuit with input resistance whose value depends on the bit weight that are

associated to. We obtain in this way the weighted resistors converter The switches

s3-s0 are driven from the digital information so that every resistance is connected


to reference voltage v ref or to ground in accordance with the fact that the

corresponding bit is at logical level 1 or 0

PROCEDURE:-

Connect the power supply to the board

Connect the D0-D3 of the logic switches to the corresponding jacks B0-B3 of

the converter

set the switches S0-S3 to logic level 0

Connect the v Ref socket to +5v connect a multimeter as voltmeter for DC to

the output v0of the converters

Switch the logic switches in binary progression &measure &recorded the output

voltage in corresponding of every combination of the input code

With input code s3 s2 s1 s0=0000 the output voltage v0 has to be null

eventually little deviation against zero are due to operational amplifier

offset


Result :-

Digital to analog converter is studied and output is verified

EXPERIMENT NO : 10

Aim :-

To study of weign bridge oscillator and effect on output frequency with variation

in RC combination


Apparatus required :-

Experiment kit

Connecting probes

DC power supply

2 mm patch cord

CIRCUIT DIAGRAM:-

Theory :-

The Weign Bridge is one of the simplest and best known oscillators and is used

extensively in circuits for audio applications Figure I shows the basic Wien bridge

circuit configuration On the positive side This circuit has only a few components

and good frequency stability Because of this simplicity and stability it is most

commonly used audio frequency oscillator The bridge has series RC network in one

arm and parallel RC network in the adjoining arm In the remaining two arms of the

bridge resistor R1 and Rf are connected .

The phase angle criterion for oscilaation is that the total phase shift around the

circuit must be zero

This condition occures only when the bridge is balanced that is at resonance.The

frequency of oscillation Fo is exactly the resonant frequency of the balanced Wien

bridge and is given by

F0 =0.159/RC


Procedure :-

1. Connect +12 v,-12 v DC power supply at their indicated position from

external source

2. Connect a 2mm patch cord between test point 1 and H

3. Switch on the power supply

4. Vary Rf pot to make gain (Rf/R1)greater than 2

5. Record the value of output frequency at test point G

6. Compare measured frequency with theoritically calculated value

7. Vary the gain pot of 470K to adjust the gain of the amplifier in case of

clipped wave form

8. Switch off the power supply

9. Connect a 2mm patch cord between test point A and B ,D and E

10. Repeat the above steps from step 3 to 8

11. Switch off the power suppy

12. Connect a 2 mm patch cord between test point B and C ,E and F


Result :-weign bridge oscillator is studied and wave form is observed


BHOPAL

INSTITUTE OF TECHNOLOGY

DEPARTMENT

OF

ELECTRICAL

& ELECTRONICS ENGG. ELECTRONIC DEVICES & CIRCUITS-I

(EX- 304)


LIST OF EXPERIMENTS

TO PLOT V I CHARACTERISTIC OF PN JUNCTION DIODE

TO PLOT V I CHARACTERISTIC OF LED DIODE

TO PLOTT VI CHARACTERISTIC OF ZENER DIODE

TO PLOT VI CHARACTERISTIC OF SCR

TO STUDY AND PLOT VI CHARACTERISTIC OF UJT

TO STUDY AND PLOT VI CHARACTERISTIC OF FET

TO STUDY OF OP AMP AS INVERTING AMPLIFIER

TO STUDY OF OP AMP AS NON INVERTING AMPLIFIER

TO OBSERVE OUTPUT WAVEFORM OF COLPITT OSCILLATOR

TO OBSERVE OUTPUT WAVEFORM OF WEIGN BRIDGE OSCILLATOR


EXPERIMENT NO: 1

AIM : To plot VI charateristic of pn junction diode

APPARATUS REQUIRED Experiment kit, Connecting probes,Multimeter

PRINCIPLE :

PN junction diode is a semiconducter device that act as switch when bias voltage is

applied to it .it turn on when forward bias condition .It act as closed switch in forward bias

condition. In reverse bias condition it act as open switch .

When positive terminal of battery is connected to P terminal of diode and negative

terminal of battery is connected to N terminal of diode then it act as forward bias PN junction diode.

PROCEDURE :

1 First we will make connection as shown in figure .

2 Then we will switch on the power supply

3 And measure input voltage using multi meter

4 Then measure output current using multimeter

5 Now plot graph using voltage along x axis and current along y axis

OBSERVATION TABLE :

V (Volt) I (mA)

RESULT :

Hence VI charateristic of PN junction diode has been plotted .


EXPERIMENT NO: 2

AIM: To plot VI charateristic of LED diode .

APPARATUS REQUIRED :

Experiment kit, Connecting probes,Multimeter

PRINCIPLE :

LED diode is a semiconducter device that act as switch when bias voltage is applied to it .it

turn on when forward bias condition .It act as closed switch in forward bias condition. In reverse

bias condition it act as open switch

When positive terminal of battery is connected to P terminal of diode and negative

terminal of battery is connected to N terminal of diode then it act as forward bias PN junction

diode.It emit light at forward bias condition

OBSERVATION TABLE :

V (Volt) I (mA)

PROCEDURE

First make connection as shown in figure

Then switch on the power supply

And measure input voltage using multi meter

Then measure output current using multimeter

Now plot graph using voltage along x axis and current along y axis

RESULT

Hence VI charateristic of LED diode has been plotted .


EXPERIMENT NO: 3

AIM: To plot VI charateristic of zener diode


Experiment kit, Connecting probes,Multimeter .

PRINCIPLE :

Zener diode is a semiconducter device which turn on under reverse bias condition. In

forward bias it act as normal pn junction diode.In reverse bias condition it turn on at particular

voltage known as reverse breakdown voltage

PROCEDURE

First make connection as shown in figure

Then switch on the power supply

And measure input voltage using multi meter

Then measure output current using multimeter

Now plot graph using voltage along x axis and current along y axis

OBSERVATION TABLE :

V (Volt) I (mA)

RESULT :

VI charateristic of zener diode is plotted .


EXPERIMENT NO:4

AIM:To plot vi charateristic of scr


Experiment kit, connecting probes multimeter

PRINCIPLE :

A Silicon Controlled Rectifier (or Semiconductor Controlled Rectifier) is a four layer

solid state device that controls current flow.The name “silicon controlled rectifier” is a trade name for

the type of thyristor commercialized at General Electric in 1957.An SCR can be seen as a

conventional rectifier controlled by a gate signal It is a 4-layered 3-terminal device.When the gate

to cathode voltage exceeds a certain threshold, the device turns 'on' and conducts current.The operation

of a SCR can be understood in terms of a pair of tightly coupled Bipolar Junction Transistors

SCR has three states:

1 Reverse blocking mode,

2 forward blocking mode,

3 forward conducting mode

PROCEDURE :

Make connection as shown in figure .

1 First switch on the power supply

2 Then measure input voltage

3 And measure output current

4 Now plot VI charateristic of SCR

RESULT :

VI CHARATERISTIC OF SCR IS PLOTTED


EXPERIMENT NO:5

AIM: To study and plot vi characteristic of UJT

APPARATUS REQUIRED:

Power electronics board PE 01., dc power supplies (+ 15 v),digital multi-meter.2mm patch cord .

THEORY:

The uni-junction transistor (UJT) is a three terminal device Emitter (E), base l

(BI) andbase2 (B2). Between base l & base2 it behaves like an ordinary resistance. Rb1 & Rb2are

internal resistance respectively from base 1 & base2.

UJT characteristics are very different from the conventional 2 junction, bipolar transistor. It is a

pulse generator with the trigger or control signal applied at the emitter. This trigger voltage is a

fraction (n) of interbase voltage, Vbb

It operates in three different regions :

1. Cut-off region

Let voltage Ve be applied between E and B 1 where E is positive with respect to B1. Now

increase this voltage from zero up to (Ve < VBB) E to B1 unijunction is reversed bias & emitter

current is negative as shown by the curve in figure 2.So up to this when Ve =VBB + VD at point R in

figure 1 it operates in cut off region, corresponding voltage & current at this point are Vp (peak

voltage) & Ip(Peak current).

2. -VE resistance region

At point R in figure 1 when Ve= VBB + VD emitter starts to inject holes into lower base

region B1. This is because of increased number of carrier in base region. So, resistance Rb1 of E-B1

junction decreases.

PROCEDURE

Connect + 15V DC power supply at their indicated position from external

Source.

1. To plot the emitter characteristics proceed as follows:

2. Rotate both the potentiometer P1 and P2 fully in counter clockwise direction.

Connect one voltmeter between test point „6‟ and ground to read VBB and other between test

point „1‟

4. Connect ammeter between point „2‟ and „3‟ to measure the emitter current

5. Vary potentiometer P2 and set a value of voltage VBB = 5 V.

6. Increase the emitter voltage Ve in steps.

7. Keep increasing Ve until it drops on voltmeter, UJT fires and emitter current flows rapidly.

8. Record the corresponding Emitter current for each value of Emitter voltage

9.. Repeat the above procedure from step 8 for VBB = 10 V and 15 V.

RESULT

UJT characteristic is plotted .

EXPERIMENT NO:6


AIM: To study of field effect transistor

THEORY :

Field effect devices are those in which current is controlled by the action of an electron field,

rather than carrier injection.Field-effect transistors are so named because a weak electrical signal

coming in through one electrode creates an electrical field through the rest of the transistor. The FET

was known as a “unipolar” transistor.The term refers to the fact that current is transported by

carriers of one polarity (majority), whereas in the conventional bipolar transistor carriers of

both polarities (majority and minority) are involved.

The family of FET devices may be divided into :

Junction FET

Depletion Mode MOSFET

Enhancement Mode MOSFET

Symbol of JFET

PROCEDURE

Connect + 15V DC power supply at their indicated position from external

Source.

1. To plot the emitter characteristics proceed as follows:

2. Rotate both the potentiometer P1 and P2 fully in counter clockwise direction.

3. Connect one voltmeter between test point „6‟ and ground to read VBB and other between

test point „1‟ and ground to read Ve.

4. Connect ammeter between point „2‟ and „3‟ to measure the emitter current

6. Vary potentiometer P2 and set a value of voltage VBB = 5 V.

7. Increase the emitter voltage Ve in steps.

8. Keep increasing Ve until it drops on voltmeter, FET fires and emitter current flows rapidly.

9. Record the corresponding Emitter current for each value of Emitter voltage Ve in an

observation table 1.

10. Repeat the above procedure from step 8 for VBB = 10 V and 15 V.

11. Plot the graph of Ve versus Ie with the help of observation table 1.used to plot different

characteristics of unijunction transistor is show

RESULT :

FET characteristic is plotted.

EXPERIMENT NO : 7

AIM: To study and observe output waveform of op amp in inverting



Analog board (ab ,42),dc power supply(+12 v,-12 v),ST2612,2mm patch cord ,

digital multi meter ,

THEORY :

Operational amplifier can be used as inverting amplifier .in this circuit r1 i connected between

inverting input terminal of op amp. r2 is connected between inverting input and output terminal of

opamp non inverting terminal is connected to ground it will produce phase shift of 1800 from input

to output .

PROCEDURE :

1 Set the value of RF= 10 K (between E and F )

2 Set the value of R OM=5K (Between H and Vin2 )

3 Connect patch cord between F&G , Vin2& gnd

4 From Function generator 1 v 1 Khz signal is applied to VIN1

5 Measure the value of VIN &VOUT

VOUT =( RF/R1)VIN

OBSERVATION TABLE

Sno VIN RF RF/R1 VOUT(calculated ) VOUT(measured ) Phase shift

1 1 10K 1 1 1 180o

2 1 20K 2 2 1.8V 180o

3 1 30K 3 3 2.8V 180o

4 1 40K 4 4 3.5V 180o

5 1 50K 5 5 4.7V 180o

6 1 60K 6 6 5.4V 180o

RESULT :

OP AMP as Inverting amplifier is studied

EXPERIMENT NO:8

AIM: Study of OP AMP as non inverting amplifier




digital multi meter , ,

THEORY :

Signal is applied to non inverting input terminal r i is connected to ground. r f is connected

between r1 and output output is measured across ouput terminal and ground output volatge

can be calculated by using equation

V OUT = (1+R F /R1 ) V IN 1

PROCEDURE :

Set the value of RF= 10 K (between E and F )

Set the value of R OM=5K (Between H and Vin2 )

Connect patch cord between F&G , Vin1& gnd

From Function generator 1 v 1 Khz signal is applied to H (non inverting input of op amp )

Measure the value of VIN &VOUT

Calculate tthe value of VOUT using the equation

VOUT =( RF/R1)VIN

Vary the value of RF and measure the value of VOUT

OBSERVATION TABLE

Sno VIN RF 1+RF/R1 VOUT(calculated ) VOUT(measured ) Phase shift

1 1 10K 2 2 2 00

2 1 20K 3 3 2.5 00

3 1 30K 4 4 3.5 00

4 1 40K 5 5 4.2 00

5 1 50K 6 6 5.2 00

6 1 60K 7 7 6.2 00

RESULT :

Op amp as non inverting amplifier is studied.

EXPERIMENT NO: 9

AIM: To study and observe the output waveform of colpitt oscillator

APPARATUS REQUIRED

Colpitt oscillator trainer kit,connecting probes Power supply,Multimeter ,CRO

THEORY :

Oscillator circuit is the circuit that produces periodic waveform there is two classes of


oscillators they are Relaxation Oscillator and sinusoidal oscillator the relaxation Oscillator is the

circuit that produces saw tooth wave form on output and in the case of sinusoidal oscilator that consist

of an amplifier and external component to generate oscillation

The two condition for oscillation that

Av .B >1

The total phase shift =00 or 360

0

Colpit oscillator is the simplest and best known oscillator used in circuit which work at

Radio frequencies transistor circuit act as voltage divider bias which set up q point output voltage

across c2 (vout) feed back to base of transistor

Resonant frequency = 1/2Π(LC)1/2

Where C= C1C2/C1+C2

starting condition for oscillation is AB>1

PROCEDURE

connect +12 power supply at their indicated position from external source or ST 2612 Analog

lab

Connect a Patch cord between points A &B and another Patch cord between points D&G really

Switch on the Supply

Connect oscilloscope between points F and G on AB 67 board

Record the value of Output frequency on Oscilloscope

Calculate resonant frequency using equation 1

Compare measured frequency with theoritically calculated value

Switch off the supply

Remove Patch cord connected between point a and b and connect it between point a and c

Remove the patch cord connected between points d and g1 and connect it between points e and g2

follow procedure from 4 to 8

Observe the waveform on CRO

OBSERVATION TABLE

RESULT :

output waveform is observed .

Resonant frequency is compared with measured frequency

EXPERIMENT NO: 10

AIM :

To study and observe output waveform of weign bridge oscillator


S NO L C1 C2 C RESONANT FQY

MEASURED CALCULATED


Experiment kit ,Connecting probes, CRO

PRINCIPLE :

The weign bridge oscillator isone of the simplest and best known oscilator and is used

extensively in circuit foe audio application.this circuit have only few components and good

frequency stability.it is connected between amplifier input terminal and output terminal

the bridge has series rc network in adjoining arm in the remaining two arms or bridge resistor

r1 and rf are connected the frequency of oscillation fo is exactly the resonant frequency of balanced

weign bridge and given by

f0= 1/2 pirc

PROCEDURE :

1 Make connection as shown in figure

2 Switch on the power suply

3 Observe output frequency on cro

4 Measure output frequency

5 Compare it with calculated frequency

RESULT :

The weign bridge oscillator is studied and waveform is observed .

BHOPAL INSTITUTE OF TECHNOLOGY, BHOPAL(M.P

LAB MANUAL

Version no EX/3.5

Subject NETWOTK ANALYSIS

Subject code EX/305


Scheme NEW

Class/Branch III SEMESTER/EX

Author MR. Aman singh kushwaha

Institution BHOPAL INSTITUTE OF TECHNOLOGY

DEPARTMENT OF ELECTRICAL & ELECTRONICS

NETWORK ANALYSIS LAB

Index Exp. no Experiment Title

1 To verify Kirchhoff’s current law & Kirchhoff’s voltage law

2 To verify Maximum Power Transfer theorem

3 To verify Norton’s theorem.

4 To verify Thevenin’s theorem.

5 To verify Superposition theorem.

6 To verify Millman’s theorem

7 To verify Reciprocity Theorem.

8 To measure the Z – parameter for SINGLE and CASCADED TWO PORT

NETWORK.

9 To measure the Y – parameter for SINGLE and CASCADED TWO PORT

NETWORK.


10 To verify ABCD Parameter for SINGLE and CASCADED TWO PORT

NETWORK.

EXPERIMENT NO. 01

AIM: To verify Kirchhoff’s current law & Kirchhoff’s voltage law.


THEORY: In simple circuit, the current and voltages are calculated with the help of ohm’s law.

But in actual practice, where we have complex circuit with several resistors, voltage sources and

current sources, it becomes difficult to calculate the current and voltage.

In these situations KVL & KCL are used.

KIRCHHOFF’S CURRENT LAW:

This law states, “The algebraic sum of various current meeting at a

node in a closed electrical circuit is zero.”

Current flowing towards the node is taken as

negative.

KIRCHHOFF’S VOLTAGE LAW:

This law states, “In a closed loop, the algebraic sum

of e.m.f.s is equal to the product of the resistances and

respective current flowing through them.”

CIRCUIT DIAGRAM:

Fig. (1)


Fig. (2)

Fig. (3)


PROCEDURE:

CASE 1: For the calculation of current I1:

Connect the circuit as shown in fig. (1)

Connect the current meter (mA) across B & C points.

Point C & D will remain open.

Apply KVL to closed mesh ABCA.

5I1 + 10I1 = 2.5

15I1 = 2.5

I1 = 166.66 mA (Calculated value)

Measure current I1 from current meter (measured value).

Compare the calculated and measured value.

CASE 2: For the calculation of current I2:

Connect the circuit as shown in fig. (2).

Connect the current meter (mA) across C & D points.

Point C & B will remain open.

Apply KVL to closed mesh ADCA.

22 I2 +33 I2 = 2.5

55 I2 = 2.5

I2 = 45.45 mA (Calculated value)

Measure current I2 from current meter (measured value).


CASE 3: For the calculation of total current I:

Connect the circuit as shown in fig. (3).


Connect B, C & D points.

Connect the current meter (mA) between the negative terminal of the battery and

point C.

Total Current I = I1 + I2

I = 212.11 mA (Calculated value)

Measure current I from current meter (measured value).


OBSERVATION TABLE:

S. No. Input Voltage Current Through Total Current

(i)

Verification of

Voltages ABCA ADCA

01.

02.

03.

04.

CALCULATIONS:

RESULT:

PRECAUTIONS:

(l) The positive & negative terminals of the power supply should not be connected

together.

(m)Supply for the experimental kit should be switched ON only after the connections are

verified.

(n) Avoid parallax error.

(o) Check the polarities of the meter before the observations are noted down.

EXPERIMENT NO. 02

AIM: To verify Maximum Power Transfer theorem.



THEORY: When the load is connected across a voltage source, power is transferred from source

to load. The amount of power transferred depends on the load resistance.

This theorem states, “Maximum power is transferred from source to load when the load

resistance is made equal to the internal resistance of the source.”

This theorem is applicable to A.C. as well as D.C. power.

CIRCUIT DIAGRAM:

PROCEDURE:

(p) Connect 12V regulated power supply in the circuit.

(q) Connect Ri and RL in the circuit. Also connect current meter and voltmeter in the

circuit.

(r) Now increase the value of load resistance RL (potentiometer) in steps and note down

the corresponding voltage and current. Calculate the power:

P = V I

(s) At a particular point when the load resistance is made equal to the internal resistance

of the source i.e., Ri , maximum power is transferred from source to load.

(t) Plot the graph between power and load resistance.

OBSERVATION TABLE:

S.NO. Ri = 100 Ω Ri =……….Ω


I (mA) V (Volts) P (watts) I (mA) V (Volts) P (watts)

GRAPH:

RESULT:

PRECAUTIONS:

The positive & negative terminals of the power supply should not be connected

together.

Supply for the experimental kit should be switched ON only after the connections are

verified.


Check the polarities of the meter before the observations are noted down

EXPERIMENT NO. 03

AIM: To verify Norton’s theorem.


THEORY: This theorem states, “Any linear, bilateral network containing a number of e.m.f.

sources and resistances can be replaced by an equivalent circuit having a current source IN in

parallel with a resistance RN.”

Where, IN is the short circuit current flowing through the output terminals and RN is the

resistance measured across the output terminals with all other sources replaced by their internal

resistances, if any.


CIRCUIT DIAGRAM:


PROCEDURE:

(u) Open the load and measure the voltage across X and Y (fig. 2).

(v) Open circuit voltage VOC across R4 = …….V.

(w) Now short circuit the voltage source with RL open (fig 3).

(x) Now disconnect the voltage source and short A and B points as shown in fig 3.

(y) Now the measure the resistance at X and Y i.e. RN.

Short Circuit Current:

IN = =……….mA.

Now the circuit may be replaced as:

IN=……….mA.

RN=……….Ω.

For RL= 25 Ω

=……….mA.

For RL= 50 Ω

=……….mA.

For RL= 75 Ω

=……….mA.


(z) Measure the current through RL.

(aa) Compare calculated and measured values.

OBSERVATION TABLE:

S. No. RL= 25Ω RL= 50Ω RL= 100Ω

IL (mA) IL (mA) IL (mA)

CACULATIONS:

RESULT:

PRECAUTIONS:


together.


verified.



EXPERIMENT NO. 04

AIM: To verify Thevenin’s theorem.



THEORY: Sometimes it is necessary to find a particular branch current in a circuit as the

resistance of that branch is varied while all other resistances, voltage sources and the current

sources remain the same.

This theorem states that,” Any two terminal network containing a number of e.m.f. sources

and resistances can be replaced by an equivalent series circuit having a voltage source VTH in series

with a resistance RTH.”

Where, VTH = Open circuit voltage between two terminals.

RTH = The resistance between two terminals of the circuit obtained by looking in at the

terminals with removed and voltage sources replaced by their internal resistances, if any.


IL =

CIRCUIT DIAGRAM:

Fig. 01


Fig. 02

Fig. 03

Fig. 04

PROCEDURE:

(bb) Connect the circuit as shown in fig 1. Measure the values of load current at

different load resistance. It is IL1, IL2 & IL3.

(cc) Connect the circuit as shown in fig. 2. Disconnect the load resistor (RL) from

output terminals and measure the open circuit voltage (VTH) by connecting analog

voltmeter. Open circuit voltage will appear across 100Ω resistor:

V =

(dd) For measurement of Thevenin’s resistance across open circuit terminals X-Y,

disconnect the 12V voltage source and short the voltage source open circuit terminals

A-B as shown in fig. 3. Connect the digital multimeter across terminal X-Y. Find the

value of RTH.


Now measure the resistance across X and Y.

RTH =

(ee) Now, above circuit between X & Y can be replaced by Thevenin’s equivalent

circuit as shown in fig 4.

VTH = 1.8 V

RTH = 173.4 Ω

For RL = 25 Ω

IL1 = = ……….mA

For RL = 50 Ω

IL1 = = ……….mA

For RL = 75 Ω

IL1 = = ……….mA

(ff) Compare the calculated and measured values.


OBSERVATION TABLE:

S. No. Measured Value Calculated Value

RL = 25 Ω

RL = 50 Ω

RL = 75 Ω

RTH

VTH

RESULT:

PRECAUTIONS:


together.


verified.




EXPERIMENT NO. 05

AIM: To verify Superposition theorem.


THEORY: When there is only one source of e.m.f. or only one current source, then it is very easy

to calculate the current or the voltage. But in a complex circuit where there are a number of

sources acting simultaneously, then it is very difficult to calculate the current or the voltages. In

these situations superposition theorem is used.

The theorem states that, “If a number of current or voltage sources are acting

simultaneously in a linear network, the resultant current in any branch is the algebraic sum of the

currents that would be produced in it, when each source acts alone replacing all other sources by

their internal resistances.”

CIRCUIT DIAGRAM:

Fig. 01


Fig. 02

Fig. 03


PROCEDURE:

(gg) Connect the circuit as shown in fig 1. Measure the current i1, i2 and i3.

(hh) Connect the circuit as shown in fig. 2. Consider only one voltage source at a time,

first 12V. Short the second 5V source. Measure the current i1’, i2’ and i3’ (One

ammeter is connected at a time, other ammeter is shorted).

(ii) Connect the circuit as shown in fig. 3. Consider only 5V voltage source. Short the

second 12V source. Measure the current i1’’, i2’’ and i3’’.

(jj) Calculate the value of i1’ , i2’ , i3’, i1’’, i2’’ and i3’’.

(kk) Compare the calculated and measured values.

OBSERVATION TABLE:

Sr. No. Measured Value Calculated Value

i1’

i2’

i3’

i1’’

i2’’

i3’’

i1

i2

i3


CALCULATIONS:

Consider only one voltage source at a time, first 12V.

RT = 50 + = 50 + 8.33 = 58.33 Ω

ITH =

IT = i1’

i3’ =

i2’ = i1’ - i3’ =……….

Therefore,

i1’ =……….

i2’=……….

i3’=……….

Now, considering 5V voltage source only:

RT = 50 + = 50 + 8.33 = 58.33 Ω

ITH =

IT = i3’’

i3’ =

i1’ = i3’ - i2’ =……….

Therefore,

i1’ =……….

i2’=……….

i3’=……….

According to superposition theorem,

Current through resistance R1 = i1’ - i1’’ =……….

Current through resistance R2 = i2’ – i2’’ =……….


Current through resistance R3 = i3’ – i3’’ =……….

RESULT:

PRECAUTIONS:


together.


verified.



EXPERIMENT NO. 06

AIM: To verify Millman’s theorem.


THEORY: This theorem states, “If several voltage sources in series with admittance are connected

in parallel as shown in figure, the equivalent circuit can be shown as a combination of an

equivalent voltage source (Veq) in series with an impedance Req.”

Here, Req =

Where, R = Resistance

Veq =

(From fig. 1)

Req =

Req =

Req = 100 Ω


Veq =

Veq =

IRL (For 220 Ω) =

IRL (For 300 Ω) =

IRL (For 400 Ω) =

CIRCUIT DIAGRAM:

Fig. No. 01

PROCEDURE:

(ll) Introduce the supplies (12V, 15V, 18V) in series with the resistance 300Ω by shorting

the dotted lines through patch chords as shown in fig. (1).

(mm) Switch ON the instrument using ON/OFF toggle switch provided on the front

panel.


(nn) Measure the Veq (equivalent voltage) with voltmeter as shown in fig. (1).

(oo) Now connect the current meter in series with load (RL).

(pp) Observe the different readings of current (IR) by introducing different load

resistances (RL = 220, 300 & 400 Ω) in the output by connecting dotted lines through

patch chord as shown in fig. (1). Compare the observed values with the calculated

values as given above. There may be a slight difference due to tolerance resistance of

resistance (± 10%).

OBSERVATION TABLE:

S. No. RL V IPRACTICAL

01.

02.

03.

GRAPH:

RESULT:

PRECAUTIONS:


together.


verified.


Check the polarities of the meter before the observations are noted down

EXPERIMENT NO. 07

AIM: To verify Reciprocity Theorem.



THEORY: This theorem states, “In any linear, Bilateral network connecting one or more

generators, the ratio of voltage (V) introduced in one mesh to the current (I) in any second mesh is

the same as the ratio obtained if the position of the voltage and current are interchanged, other

e.m.f. being removed.”

Fig. 1(a)

Fig. 2(b)

PROCEDURE:

(qq) Connect the circuit as shown in fig 1(a).

(rr) Switch ON the instrument.


(ss) Note down the value of current I3.

(tt) Switch OFF the instrument and interchange the position of the voltage source and

current meter as shown in fig 1(b). Again switch ON the instrument.

(uu) Note down the value of current I1.

(vv) We observe that the value of current I3 is equal to the value of current I1. This

proves the RECIPROCITY THEOREM.

(ww) Similarly we can prove the theorem for the combinations of resistors.

OBSERVATION TABLE:

S. No. Circuit 1 Circuit 2

I3 (mA) I1(mA) I1 (mA) I3 (mA)

01.

02.

03.

CALCULATIONS:

RESULT:

PRECAUTIONS:


together.


verified.



EXPERIMENT NO. 08


AIM: To measure the Z – parameter for SINGLE and CASCADED TWO PORT NETWORK.


THEORY: A given two port network, with some degree of complexity, can be built up from

simple two port networks, whose ports are interconnected in certain ways. Conversely, a two

port network can be designed by combining two port structures as building blocks.

There are a number of ways in which two port networks can be interconnected. The

simplest possible interconnection is termed as Cascade or Tandem connection. Two port

networks are said to be cascaded if the output of first becomes the input of the second.

CIRCUIT DIAGRAM:

Fig. 01

Fig. 02

PROCEDURE:


(xx) Connect the circuit as shown in fig 1. It means, connect the variable voltage supply

to the input terminals of the network – I.

(yy) Vary the input voltage to 10V (V1) and measure the open circuited output voltage

(V2). Note down the input current through current meter.

V1 = Input voltage = 10V

V2 = Output voltage

I1 = Input current (Observed from current meter)

I2 = 0 (because output is open circuited)

(zz) Now short the output terminals and measure input current

V1’ = Input voltage = 10V

V2’ = 0

I1’ = Input current

I2’ = Output current

(aaa) With these values calculate Z – Parameter for SINGLE TWO PORT NETWORK.

Z11 = I2 = 0) Ω Z12 = I2 = 0) Ω

Z21 = I1 = 0) Z22 = I1 = 0)

(bbb) Now connect the output of the first network to the input of the second network.

(ccc) Apply variable voltage to the input terminals and adjust the voltage to 10V.

(ddd) Now record.

V1 = Input voltage

V2 = Output voltage

I1 = Input current

I2 = Output current = 0


(eee) Interchange output and input terminals and measure the input voltage and

current and output voltage.

With these values calculate Z – parameter for cascaded network (repeat step 4).

OBSERVATION TABLE:

CALCULATIONS:

Z11 = I2 = 0) Ω Z21 = I2 = 0) Ω

Z21 = I1 = 0) Z22 = I1 = 0)


RESULT:

PRECAUTIONS:


together.


verified.




EXPERIMENT NO. 09

AIM: To measure the Y – parameter for SINGLE and CASCADED TWO PORT NETWORK.


THEORY: A given two port network, with some degree of complexity, can be built up from

simple two port networks, whose ports are interconnected in certain ways. Conversely, a two

port network can be designed by combining two port structures as building blocks.


simplest possible interconnection is termed as Cascade or Tandem connection. Two port

networks are said to be cascaded if the output of first becomes the input of the second.

CIRCUIT DIAGRAM:

Fig. 01


Fig. 02

PROCEDURE:

(fff) Connect the circuit as shown in fig 1. It means, connect the variable voltage supply

to the input terminals of the network – I.

(ggg) Vary the input voltage to 10V (V1) and measure the open circuited output voltage

(V2). Note down the input current through current meter.


V2 = Output voltage

I1 = Input current (Observed from current meter)


(hhh) Now short the output terminals and measure input current I1’.

V1’ = Input voltage = 10V

V2’ = 0

I1’ = Input current = 0.0062 A

I2’ = Output current = 0.004 A

(iii)With these values calculate Z – Parameter for SINGLE TWO PORT NETWORK.


Y11 = V2 = 0) Ω Y12 = V2 = 0) Ω

Y21 = V1 = 0) Y22 = V1 = 0)

(jjj) Now connect the output of the first network to the input of the second network.

(kkk) Apply variable voltage to the input terminals and adjust the voltage to 10V.

(lll)Now record.

V1 = Input voltage

V2 = Output voltage = 5012 V

I1 = Input current = 0.0062 A


(mmm) Interchange output and input terminals and measure the input voltage and

current and output voltage.

With these values calculate Z – parameter for cascaded network (repeat step 4).

OBSERVATION TABLE:

S. No. RL= 25Ω RL= 50Ω RL= 50Ω

IL (mA) IL (mA) IL (mA)

CALCULATIONS:

Z11 = I2 = 0) Ω Z21 = I2 = 0) Ω

Z21 = I1 = 0) Z22 = I1 = 0)


RESULT:

PRECAUTIONS:


together.


verified.




EXPERIMENT NO.10

AIM: To verify ABCD Parameter for SINGLE and CASCADED TWO PORT NETWORK.


THEORY: A given two port network, with some network of complexity, can be built up from

simple two port networks, whose ports are interconnected in certain ways. Conversely, a two-

port network can be designed by simple two port structures as building blocks.


simplest possible connection is termed as Cascade or Tandem connection. Two port networks are

said to be cascaded if the output of first becomes the input of second.

CIRCUIT DIAGRAM:

Fig. 01


Fig. 02

PROCEDURE:

(nnn) Connect the circuit as shown in figure 1. It means connect the variable voltage

supply too the input terminal of the network – I.

(ooo) Vary the input voltage to 10V (V1) and measure open circuited output voltage (V2).

Note down the input current through current meter.


V2 = Output voltage

I1 = Input current (observed from current meter)


(ppp) Now short the output terminals and measure Input current I1’.

V1’ = Input voltage

V2’ = 0

I1’ = Input current

I2’ = Output current

(qqq) With these values calculate ABCD Parameters for single port network.

A = (I2=0) B = (V2=0) Ω


C = (I2=0) D = (V2=0)

(rrr) Now connect the output of the first network to the input of the second network.

(sss) Apply variable voltage to the input terminals and adjust voltage to 10V.

(ttt) Now record

V1 = Input voltage

V2 = Output voltage

I1 = Input current


(uuu) Interchange output and input terminals and measure the input voltage, current

and output voltage.

(vvv) With these values calculate ABCD parameters for cascaded network (repeat step

4).

OBSERVATION TABLE:

CALCULATION (ABCD parameters):

A = (I2=0) B = (V2=0) Ω

C = (I2=0) D = (V2=0)

RESULT:

PRECAUTIONS:


together.



verified.





LAB MANUAL

Version No. EX/3.6

Subject Java

Subject Code EX-306

Scheme New

Class/Branch III Semester

Author CS/IT Deptt


1. Write a program to show multiple statements in java.

Class statements

Public static void main (String args [ ])

System.out.println ("This is my program...");

System.out.println ("I have a copy right for it...");

Output

This is my program...

I have a copy right for it...


2. Write a program to accept a no. and check whether it is even or odd.

Cass check

public static void main (String args [ ])

int a= Integer.parseInt(args [0]);

if(a= =0)

System.out.println ("ZERO");

else if (a%2= = 0)

System.out.println (a+ "It is even");

else if (a%2= = 1)

System.out.println ("It is odd");

Output

If enter a =0 then print ZERO

If enter a =2 then print even

If enter a =1 then print odd


3. Write a program to accept a character and check whether its constant or vowel. (Using switch

statements)

class paper

public void main(char character)

switch(character)

case 'a':

System.out.println ("It is a vowel");

break;

case 'A':


break;

case 'e':


break;

case 'E':


case 'i':


break;

case 'I':

System.out.println("It is a vowel");

break;

case 'o':


break;

case 'O':


break;

case 'u':


break;

case 'U':


break;

Output

If ‘a’ was entered……

It is a vowel

Any other character entered…..

It is a consonant


4. Write a program to square root of any value.

Import java.lang.Math;

Class squareroot

public static void main(String args [ ] )

Double x = 25

double y=Math.sqrt(x);

System.out.println ("The square root is "+y);

Output

The square root is 5.0

5. Write a program to concept of multiple classes in java.

Class demo

public static void main(String args [ ])

System.out.println("**beginning execution**");

Greeter greeter = new Greeter();

System.out.println("**created Greeter**");

greeter.greet();

class Greeter

private static Message s_message = new Message("Hello, World!");

public void greet()

s_message.print(System.out);

class Message

private String m_text;

public Message(String text)

m_text = text;

public void print(java.io.PrintStream ps)


ps.println(m_text);

Output

**beginning execution**

**created Greeter**

Hello, World!

6. Write a program to show type casting in java.

Class casting

public static void main(String args [ ] )

float sum;

int i;

sum = 0.0f;

for (i=1; i<=10; i++)

Sum = sum+1 / (float)i ;

System.out.println("i="+i);

System.out.println("sum ="+sum);

Output

i= 1 sum =1

i= 2 sum =1.5

i= 3 sum =1.83333

i= 4 sum =2.08333

i= 5 sum =2.28333

i= 6 sum =2.45

i= 7 sum =2.59286

i=8 sum =2.71786

i= 9 sum =2.82897

i= 10 sum =2.92897

7. Write a program to show use and advantages of constructor.

Class Rectangle

int length, width;

Rectangle (int x, int y)

length = x;

width = y;

int rectarea( )

Return(length*width);

Class Rectangle area

Public static void main (String args [ ])

Rectangle rect1 = new Rectangle (15, 10); //calling


constructor

int area1 =rect.rect1.rectarea( );

System.out.println(“Area1 = ”+area);

Output

Area1 = 150

8. Write a program to show how exception handling is in java.

Class error

Public static void main (String args [ ] )

int a =10,b=5,c=5,x,y;

try

x = a/(b-c); // exception

Catch (Arithmetic exception)

System.out.println("Division by zero");

y = a/(b+c);

System.out.println("y="+y);

Output

Division by zero

y = 1


9. Write a program to show method overloading in java.

Class Room

float length;

float bridth;

Room(float x ,float y ) // constructor 1

length = x;

breadth y;

Room(float x) // constructor 2

(Overloading of method)

length = breadth = x ;

int area ( )

Return (length*breadth);

Output

Room room1 =new Room (25.0, 15.0); //using constructor 1

Room room2 =new Room (20.0); //using constructor 1


10. Write a program to show “Hello Java” in explorer using applet.

import java.applet.*;

import java.awt.*;

class Hello Java extends Applet

public void paint(Graphics g)

setBackground(Color.GREEN);

g.setColor(Color.WHITE);

g.drawString("Hello Java", 10,100);

<html>

<applet code=" Hello Java t" width=10 height=100></applet>

</html>

Output

↑

100 Hello Java____↓___

←



LAB MANUAL

Version No. EMEC-I (EX-401)

Subject EMEC-I (EX-401)

Subject Code EX-504

Scheme New

Class/Branch IV Semester / all

Author Pajan Gangele


BHOPAL INSTITUTE OF TECHNOLOGY, BHOPAL(M.P) DEPARTMENT OF ELECTRICAL & ELECTRONICS

E.M.E.C-I Lab.

Index

Exp. no Experiment Title

1 To perform open circuit and short circuit test on 1-phase and 3-phase transformer and determine its equivalent circuit parameters.

2 To perform open circuit and short circuit test on 1-phase and 3-phase transformer and determine its efficiency and regulation at. i Full load at unity power factor. ii Full load at zero power factor lead and lag. iii Half the full load at 0.8 power factor lead and lag.

3 Perform Sumpner’s test on 2 Single phase Transformers.

4 To perform the parallel operation of two, 1-phase transformer and observe


load sharing.

5 To perform the No load and block rotor test of 3-phase induction motor and to determine its equivalent circuit parameters.

6 To perform the No load and block rotor test of 3-phase induction motor to draw the circle diagram.

7 To perform the load test on 3-phase induction motor and draw its performance characteristic

8 Swinburn’s test on D.C. motor & determine its efficiency.

9 To perform speed control of D.C. motor.

10 To plot OCC on a separately excited D.C. Generator.

11 Perform load test on D.C. Generator.

EXPERIMENT-1

AIM:- To Perform Open Circuit and Short Circuit test on transformer.

APPARATUS REQUIRED:-

S.No.NAME RANGE Quantity

1Ammeter 0-5AMP 1

2Ammeter 0-1 AMP 1

3Voltmeter 0-300V 1

4Autotransformer

0-270V 1

5Wattmeter 0-375Watt 1

6Single Phase Transformer

2KVA,220V,50Hz 1


THEORY:-

In various experiments, transformer is being operated normally under one of the following condition. 1 . OPEN CIRCUIT:-

Generally high voltage Winding is open circuited is open circuited . such a test is performed at rated voltage applied to low voltage winding no load test is performed to find out the no load / core losses. 2. SHORT CIRCUIT TEST:- Low voltage winding is generally short circuited and quite low Voltage applied o high voltage winding. such a test is normally performed under full Load current condition. This test is performed to find out full load losses. CIRCUIT DIAGRAM :-

PROCEDURE :-

(www) Open circuited test

1 Connect the circuit as per the circuit diagram.


2 Ensure that the setting of the variac is at ow output voltage. 3 Switch on the supply and adjust rated votage across the transformer circuit . 4 Record no load current , voltage applied and no load power, corresponding to

the rated voltage of the transformer winding . 5 Switch off the AC supply.

(xxx) Short circuit test

1 Connect the instruments as per the circuit diagram. 2 Adjust the setting of the variac so that the output voltage is zero. 3 Switch on the AC supply to the circuit. 4 Increase the voltage applied slowly till the current in the winding of the

transformer is full load rated value. 5 Record short circuit current, corresponding applied voltage and power with full

load current under short circuit condition. 6 Switch off the AC supply.

OBSERVATION TABLE:-

S.No Open circuit test Short circuit test


1 220 V .34 A 14 Watt 18 V 9.5 A 120 Watt

2

CALCUATIONS:-

For open circuit test

Wo =Vo Io Cos Фo Cos Фo = Wo / Vo Io Io Cos Фo = Ic or Iw Io sin Фo = Im Io = √ (Ic2 + Im2) Ro = Vo / Ic Xo = Vo / Io

For short circuit test

Wsc = Isc2 Req. Req. = Wsc / Isc2

Zeq. = Vsc / Isc Xeq. = √( Z2 – R2)


Result:- Transformer Equivalent parameters are obtained. Precaution :-

1. Make the connection correct & according to the circuit diagram. 2. All connection should be made with power supply off. 3. Signal should not be applied to the input while the instrument power supply on.

EXPERIMENT-02

AIM:- Perform Sumpner’s test on 2 Single phase Transformers.

(a) To perform sumpner"s (Back to Back) test on two identical transformer (b) Determine the efficiency at 1/4 1/2 3/4, full load 1.25 times the full load and at 0.85 p.f lagging

1. plot efficiency vs output characteristic. APPARATUS REQUIRED:-


1Ammeter 2.5-5A 1

2Ammeter 15/30 A 1

3Voltmeter 0-300V 1

4Voltmeter 0-600V 1

5Wattmeter 2.5 A/200 V 1

6Wattmeter 15 A/75 V 1

7Single Phase Transformer

2KVA,220V,50Hz 2

THEORY :- This test needs two identical transformer. The primary windings of these transformer are connected in parallel and supplied at rated voltage and frequency, while the two


secondaries are connected in phase opposition as shown in FIg Thus the voltage across the two secondaries is zero, when the primary windigs are energized as such,this test is also called back to back test.in thes test, iron losses occur in the core and full load copper losses occur in the windings of the two transformer, current flowing in the two secondaries is rated fullload current of the transformer. thus heat run test can be conducted on the transformer without acttually loding them and hence steady-state temperature-rise of the transformer can be estimated.the current drawn by the primaries is twice the no load current of each transformer. the watmeter w1 connected in thecircuit of the primaries measures the total core losses of booth the transformers. Similarly wattmeter W2 connected in the secondary circuit measures the total full copper losses of the two transformer. PROCEDURE :-

Connect the circuit as per the diagram. Ensure that swithes S2 and S3 are open. Energize the primaries by closing the swith S1. Observe the reading of voltmeter V1 which should be for correct connections of the

secondaries. incase, the voltmeter reted voltage of each transformer,open the swith S1 and interchange the connection at the secondary terminals of one of the transformer.close the switch S1 again and verify that the voltmeter V1 nowreads zero important caution ; Eeven if the voltmeter V1 reads zero at the first instance, it is advisable to chee the reading of voltmeter V1 by interchanging at the secondary terminals of one of the transformer.

Adjust the setting of the varic to give nearly zero out pot voltage Replacethe voltmeter V1 by alow range voltmeter. Close the switch S3 and then S2. Adjust the outpot voltage of the variec so that the current flowing in the secondaries is

full load secondary current of each transformer. Record the reading of all the instruments conneted in the primary and secondary

current of each transformer. Switch off the supply to primary and secondary circuits.

CIRCUIT DIAGRAM :-


OBSERVATIONS :-

Result:- Transformer Loss & Efficiency are obtained. Precaution :-


EXPERIMENT-03

AIM:- a) To operate the two transformers in parallel b) To study the load sharing by each transformer



1Ammeter 0-15A 2

2Ammeter 0-30 A 1

3Voltmeter 0-300V 1



6Inductive Load

250 V,7.5 KW 1

THEORY :-

Parllel operation of transformer is frequently necessary in the power system netwok, which consist of number of transformer installed at geerating stations, etc. when operrating two or more transformer in parallel (on the primary as secondary sides) their satisfactory perfomance require that the following conditions be satisfied. DIAGRAMS:-

S. No.

Primary Side Secondary Side



PROCEDURE:- Polarity Check:-

1. Connect the circut as shown in Figure. 2. Swith on the supply to the primary cricuit, where the primaries of both the transfrormrs

are conneted in parallel. 3. The voltmeter connected in the secondary cricuit of the transformers will read either

zero or twice secondary terminal voltage of each Transformer.


Parallel Operation:- 1. Connect the cricuit as per the cricuit digram shown in figure. Ensure that the two

secondaries have been connected properly as per the polarity determined in part (A). 2. Close the switch S1 to energize both the primaries. ensure that the switch S2 is kept

opem. in case the voltage ratio of the two transformers are unequal there will be a circulating current, which may be recorded.

3. Close the switch S2 Adjust a particular load on the secondaries and record the redings of all the instruments conncted in the circyit.

4. Repeat step 3 for various values of load current upto the rated capcity of the two transformer operrating in parallel.

5. Swicth off the load slowly. Open the swicth S2 and then swicth off the supply to the primaries of the transformers.

OBSERVATIONS:-

Result:- Parallel Operation of Transformer is done. Precaution :-


S. No. V Line I Line Wline I1 W1 I2 W2


EXPERIMENT NO -04

AIM:-To perform the No load and block rotor test of 3-phase induction motor to draw the

circle diagram. APPARATUS REQUIRED: -


1Ammeter 0-10/20 A 1

2Voltmeter 0-300/600V 1

33-PHASE Autotransformer

0-15A 0-400V 1

4Wattmeter 0-10 A,200/400V 1

THEORY:- To draw the circle diagram of 3 phase induction motor,following data is essential. No load current , Io and its power factor Фo. Short circuit current, Isc' corresponding to rated voltage and its power factor angle

Фsc. No Load test:- To obtain no load current and its power factor angle Фo, no load test is performed at rated voltage and frequency. Let the readings of ammeter, voltmeter and two wattmeter


connected in the circuit be, Io Vo, Wo1 and Wo2 respectively during the no load test. Then, tan Фo = √3 Wo1 - Wo2 Wo1 + Wo2 Hence, No load power factor angle, Фo can be calculated from the readings of the two wattmeters. No load current , Io has been directly measured by ammeter. Bloack rotor Test:- To obtain short circuit current and its power factor angle ,block rator test is performed on the moter. In this test rotor is not allowed to move and reduced voltage of rated frequency is aplied to the stator winding.this test is performed with raed current flowing in stator winding. Let the readings of ammeter, voltmeter and two wattmeter connected in the circuit be, Isc Vsc, Wsc1 and Wsc2 respectively during the block rotor test. Then, tan Фsc = √3 Wsc1 - Wsc2 Wsc1 + Wsc2 Thus short circuit power factro angle , Фsc can be calculated from the above equation. Short circuit current, Isc observed during the block rotor test corresponding to reduced applied voltage, Vsc which should be converted to rated voltage of the motor for plotting the circle diagram. The relation between the short circuit current and the applied voltage is approximately a straight line. Thus, short circuit current, Isc' corresponding to rated voltage V of the motor is given by, Short Circuit Current Isc' = V* Vsc It may be remembered, that the power factor of the motor is quite low at no load as well as under the block rotor condition. Thus,one of the wattmeter connected in the circuit will give negative reading in both the test. CIRCUIT DIAGRAM:-


PROCEDURE:- NO LOAD TEST:-

connect the circuit as per fig Ensure that the motor is unloaded and the variac is set at zer position . Switch on the supply and increas the voltage gradually till the rated voltage of the

motor. Record the reading of all the meters. Switch off the AC supply.

BLOCK ROTOR TEST:-

5. Readjust the variac at zero position. 6. Change the range of all the instruments for the block rotor test. 7. Block the rotor by either by tightening the belt firmly or by hand. 8. Switch on the AC supply and apply reduced voltage, so that the input current drawn

by the motor block rotor condition is eqal to the full load current of the motor. 9. Record the readings of all the meters. 10. Switch off the AC supply. 11. Measure the resistance per phase of the stator winding following Ohm's Law

concept. OBSERVATION :-

S. No.NO Load Test Block rotor Test

Vo Io Wo1 Wo2 Vsc Isc Wsc1 Wsc2


Result:- Parallel Operation of Transformer is done. Precaution :-


EXPERIMENT-05


OBJECTIVES:- To perform the load test on 3-phase induction motor and draw its

performance characteristic. APPARATUS REQUIRED: -

S.No.

Name Type Range Quantity

1 Ammeter M.I. 0 – 10 A 1

2 Voltmeter M.I. 0 – 300/600V 1

3 Wattmeter Dynamometer 5/10 A, 150/300/600V

2

4 3-Φ Variac Fully Variable 0 – 470 V 1

5 Tachometer Digital 0 – 2000rpm 1

THEORY :-

The load test on induction motor is performed to compute its complete performance i.e. torque , slip , efficiency, power factor etc. During this test , the motor is operated at rated voltage and frequency and normally loaded mechanically by brake and pulley arrangement from the observed data, the performance can be calculated, following the steps given below. SLIP:- The speed of the rotor, Nr droops slightly as the load on the motor is increased. The synchronous speed, Ns of the rotating magnetic field is calculated, based on the no. of poles, P and the supply frequency , f i.e. Synchronous speed, Ns = (120 f ) / P rpm Then Slip, S = [ Ns- Nr / Ns] * 100 Normally, the range of slip at full load is form 2 – 5 %. The output power in watts developed by the motor is given by, Output Power, PO = 2 П NT watts 60 Where, N is the speed of the motor in rpm Input power is measured by the two wattmeters , properly connected in the circuit. Input power = (W1+W2) watts Where W1 and W2 are the readings of the two wattmeters. INPUT POWER FACTOR:- Input power factors can also be calculated from the reading of the two wattmeters for balanced load. If Φ is the power factor angle , then Tan Φ = √3 ( W1 – W2 ) ( W1 + W2 ) Knowing the power factor angle ,Φ from the above ,power factor cos Φ can be calculated. It may be noted clearly at this stage, that the power factor of the induction motor


is very low at no load, hardly 0.1 – 0.25 lagging. As such, one of the wattmeter will record a negative reading , till the power factor is less than 0.5, which may be measured by reversing the connections of the current coil or the pressure coil of this wattmeter. EFFICIENCY:- % efficiency of the motor , η = output power X 100 % input power Full load efficiency of 3-phase induction motor lies in the range of 82 % (for small motors ) to 92 % (for very large motors).

PROCEDURE:-

1. Connec

t the circuit as per the circuit diagram. 2. Ensure that the motor is unloaded and the variac is set at zero output voltage. 3. Switch on 3 –phase ac mains and start the motor at reduced applied voltage. Increase

the applied voltage , till the rated value. 4. Observe the direction of rotation of the motor . In case it is reverse, change the phase

sequence of the applied voltage. 5. Take down the readings of all the meters and the speed under no load running. 6. Increase the load on the motor gradually by turning of the hand wheels, thus tighting

the belt. Record the readings of all the meters and the speed at every setting of the load. Observations may be continued upto the full load current rating of the motor.

7. Reduce the load on the motor and finally unload it completely. 8. Switch of the supply to stop the motor. 9. Note down the effective diameter of the brake drum. 10.

OBSERVATIONS:-

S. No..

I P input Torque P Output Slip Power Factor

Efficiency


CALCULATIONS:- Result:-

Parallel Operation of Transformer is done. Precaution :-


EXPERIMENT-06

OBJECTIVES:-

(a) To perfor swinburn’s test on the dc machine runnig as shunt motor at no load. (b) To measer the resistance of armature windig. (c) Determine the effiency of the machine useed as 1/4th, 1/2,th, 3/4th, full and 1.25 time

the load and plot the efficency Vs load curve. (d) Determine the efficiency of the machine used as generator atthe above and plot the

efficincy curve on the same graph.

APPARATUS REQUIRED: -

S.NO NAME TYPE RANGE QUANTITY 1 Ammeter mc 0-2A 1 2 Ammeter mc 0-5a 1 3 Ammeter mc 0-25A 1 4 Voltmeter mc 0-300V 1 5 Voltmeter mc 0-30V 1


6 Rheostat single tube 290 ohm, 1.4A 1 7 Technometer digtal 0-2000rpm 1 8 Lamp bank load resistive 250 V 5kw 1 THEORY:- Swinburne’s test is an indirect method (without loading) for finding out the

efficiency of dc machine. various losses are directly proportional to the square of armature current or approximately load current , where as constant losses are independent of load conditions. In this method constant losses are determined experimental by oproporting the dc machine as motor runnig at no load variable losses occuring on load are caculated from the known specifications of the machine. Let the voltage applied to the shunt motor be V volts and the current folwing in the armature and shunt field circuit under no load runnig be Iao and Ish respectively. Then, Inpot power to the armature circuit = V X Iao watts Inpot power to the shunt field circuit = V X Ish watts Total inpot power to the motor atno load, Wo = V X (Iao + Ish ) Armature copper losses at load = Iao X Ra Thus, The constant losses of the machine, Wc = Wo- IaoRa watts. Hence the constant losses of dc machinne can be determined expermentally by recording Iao, Ish, V and measuring the armature resistance Ra. The swinburne’s test should be performed at rated voltage and at rated speed. CALULATION OF EFFICIENCY AS SHUNT MOTOR Let the output of the motor as taken from name plate specifications = Po watts Appoximate value of full load efficiency assumed,& = 85 % Thus, input power to the motor = PO/0.85 =V X Il Hence, line current drawn by the motor under full load condition, Il = Po/0.85 x v Armatur current under full load IA = il - Ish Thus, armature copper losses at full load = IaRa Total losses at full load = Wc + IaRa Hence, efficiency of the motor at full load $ = Po/Po + Wc + IaRa x 100% Similarly, efficiency at 50 % full load mf/2 = Po/Po/2 + Wc + (1/2) IaRa x100% Efficiency at all other loads can be calculated in a similar way CALCULATION OF EFFICIENCY AS A SHUNT GENERATOR Full load outpot of the generator, Po and its rated terminal voltage, V are obetained from the name plate specification of the machine. Full load output of the generator, Po = V X Il watts Thus full load current , Il = Po/V


Armature current at full load Ia = Il, + Ish Full load armature copper losses = Ia Ra Thus total losses at full load = Wc + Ia Ra Hence, the efficiency of the generator at full load = PROCEDURE (a) For conducting swinburne’s test 1 ; Connect the dcmotor as per 2 ; Ensurethat the external resistacein the field circuit is zero. 3 ; Switch on the dc supply to the motor and startar it with the help of staerter is not provided with the motor , then arheostat of 45 ohm 5A can be fully inserted in the armature cricuit at the instant of starting the motor and should be cut out after the motor has picked up the speed Ensure that the voltage applied to the motor is of rated value Adjust the speed of the3 motor to rated value by varying the resistance in the feld cricuit. 5 ;Record the readings of all the meter connected in the circuiting 6 ; To stop the motor switch off dc supply (b) For measurment of armature resistance ;


1 ; Connect the cricut as per fig 2 ; switch on the dc supply 3 ; switch on some bubls in the lamp bank load so that current flowing in the armature cricuit is the rated full load current of the dc motor wait for 30 minutes with the full load current flowing in the armature winding so that the temprature of the armature winding appoximately becomes equivalent to that obtained under workig conditions 4 Record the readings of both the meters connected in this cricuit 5 ; switch off the dc supply. OBSERVATION ; May be tabulated as follows. FOR SWINBURNE’S TEST FOR ARMATURE RESISTACEIN

S. No V Iao Ish S.No Va Ia Ra EXPERIMENT-07

AIM:- TO study the speed control of dc motor 1.Instrument :-

S.No. Name Range Quantity

1 DC motor 220Vdc,1500rpm 1

2 Rheostat 2250ohm,1.6amp 1

3 Techometer 0-10000rpm 1

4 Ammeter 0-1amp 1

5 Multimeter Ac/dc 1

2.Theory:- -

the motor can be increased by decreasing the flux or the shunt field current ,which can be achieved by inserting a rheostat in the shunt field circuit of the motor .

circuit of the speed higher than the rated values is obtained y using this method of control. Let the external resistance in the armature circuit of the dc shunt motor be R ohm , then the

speed equation modifies to -


Hence the speed of the motor decreases with an increase in the value of external resistance R. thus reduces the speed lower than the no load speed .can be obtain by this method .however there is an excessive wastage of power in the additional resistance ,which lowers the efficiency of the motor considerably.

4 Circuit diagram:-

5

Procedure:- For Field Control:- Connection the dc motor as per the circuit diagram. Insure that the external resistance is the armature circuit is maximum.

Insure that the external resistance in the field circuit is minimum. After insuring 2, 3, switch on the dc supply as a result motor will start

running at a low speed .

Cut out the external resistance in the armature circuit and adjust the field current ,so that the speed of the motor becomes rated speed .

The armature resistance is kept constant to the above value, very field current by varying the external resistance in the field circuit . record the field current and corresponding speed.

Switch off the main supply to stop the motor For Armature Control:-

7) Connect the dc motor as per the circuit diagram 8) Insure that the external resistance is the armature circuit is maximum (starter

resistance) 9) Insure that the external resistance to the field circuit is constant. 10) After insuring 2,3,switch on the dc supply as are result motor will start running

at a low speed. 11) Cut out the external resistance in the armature circuit of starter and very the

rheostat. 12) The field current is kept cosecant to the above vaue ,vary the voltage

applied to armature by verging the external resistance in the armature circuit record the applied voltage and corresponding speed.

13) Switch off the main supply to stop the motor. 5 .OBSERVATION TABLE(For Field Control):-

S Field current Speed (rpm)


.NO.

1

2

3

4

5

6

7

8

OBSERVATION TABLE(For Armature Control):-

S.NO.Armature current Speed (rpm)

1

2

3

4

5

6

6. Conclusion:- As the field current is decreased speed of the motor is increased. Result:- Precautions:-

1. There should not be any loose connection. 2. Take the reading carefully


EXPERIMENT-08 AIM:- To plot OCC on a separately excited D.C. Generator. APPARATUS:-

S.No.


1 Ammeter M.I. 0 – 2 A 1

2 Voltmeter M.I. 0 – 300V 1

3 Rehostat sigle tube 272 Ὡ 1.7 A 2

4 Tachometer Digital 0 – 2000rpm 1

Theory - The emf generated in the armature windiing of a DC generator under no load operration is given by Eg = PФNZ 60A = K Ф N (p,z and A are constant for a particular generator) Hence at constant given speed ,no load emf , Eg is directly proportional to the flux per pole Ф, which in turn depends upon the field current , If. The characteristic curve showing the relationship between the field current If. And the generated EMF Eg at No Load and at a constant speed is known as magnetization characteristic or Open Circuit Characteristic (OCC) of DC generator. A small EMf hardly of the order of 10 to 15 V is generated by the generator when the field current is zero which is due to the residual magnetism in the poles. This characteristic of DC shunt generator is obtained by separately exciting the field.

Critical resistance of the field cricuit can be obtained by drawing a tangent to the intial portion of the magnetization characteristic the slope of wich gives the value of the critical resistance.


The plot the field resistance line on the megnetization curve record the voltage across the shunt field during experimentation. The magnetization characteristic of a particular generator will be different for different speed. various points on the megnatization curve corresponding to aspeed N2 can be obtained knowing the emf Eg corresponding to the rated speed N1 and uttillzing the equation given by, No load emf be speed N2 Eg x N2/ N1 (Eg = k N ) It may be noted clearly that Eg1 and Eg2 are the no load emf corresponding to same field cuerrent but for different speeds N1 and N2 respectively. CIRCUIT DIGRAM - Fig shows the cricuit diagram, in which the field of the shunt generator is separately excited to have awide vaariation in field current. V arious instruments connted in the circuit daigram serve the function indicated against each.

DC MOTOR - Acts as aprme move for the generator.

Rheostat - used as variable resistance in the field circuit of the motor to maintain the speed constant at rated valu during this experimentation. Rheostat - Used as potential divider to feed the fied circuit of the genrator and vary the field current in a wide range. Ammeter - To measure the field current of the genrator. Voltmeter - To measure the field current of genrator. PROCEDURE -

1. Connet the dc motor and the dc genrator ( coupled together) as per fig 2. Adjust the rheostat inthe field cricuit of the motor so that the additional resistace in this crircuit is zero. 3. Set the potential divider feeding the field cricuit of the genrator for zero output voltage. 4. swich on the dc supply to the dc motor and start it using the stater. move the stater arm slowly till the motor builds up the speed and finally cut out all resistance steps of the stater. stater are will then be hold up by the holding manet of the stater. 5. Adjust the speed ofthe dc motor to rated value by vaying the resistacein in the field cricuit . 6. Record the genrated emf due to residual magentism 7. switch- on the dc supply across the field cricut of the generator. 8. Vary the field current of genrator in steps and record its value and the correspoding genrated emf of the genrator. Observaions should be continued upto the generted voltag 25 per cent higher than rated voltage of the genrator. 9. To plot the field resistacein line record the voltage across the field of the genrator. 10. Switch off the dc supply, to stop the motor and also to disconnecct the generator field. OBSERVAIONS : mAF


EXPERIMENT-09 AIM:- To study the load characteristics of DC shunt generator . APPARATUS REQUIRED:- -

S.No.Name Range Quantity

1DC motor 220VDC 1

Ammeter 0-5amp 1

DC shunt generator

220Vdc,1500rpm 1

Lamp 200w bulb 6

Volt meter 0-300V 1


BHOPAL


DEPARTMENT

OF

ELECTRICAL

& ELECTRONICS ENGG. ELECTRONIC DEVICES & CIRCUITS-II

(EX- 404)


LIST OF EXPERIMENT

Study of OP-AMP characteristic

OP-AMP as inverting amplifier

OP_AMP as non inverting amplifier

OP_AMP as differential amplifier

Study of transister amplifier in CE configuration

Study of FET amplifiers

Study of feedback amplifiers

Study of Power amplifiers

Study of tuned amplifiers

Study of weign bridge oscillator


EXPERIMENT NO 1

AIM :Study of OP-AMP characteristic

PRINCIPLE :

An Operational amplifier ("op-amp") is a

DCcoupled high-gain electronic voltage amplifier with a differential input

and, usually, a single-ended output. An op-amp produces an output voltage

that is typically hundreds of thousands times larger than the voltage

difference between its input terminals.

Operational amplifiers are important building blocks for a wide range

of electronic circuits. They had their origins in analog computers ,where they were

used in many linear, non-linear and frequency-dependent circuits. Their popularity

in circuit design largely stems from the fact the characteristics of the final

elements (such as their gain) are set by external components with little dependence

on temperature changes and manufacturing variations in the op-amp itself.

Op-amps are among the most widely used electronic devices today, being

used in a vast array of consumer, industrial, and scientific devices. Many standard

IC op-amps cost only a few cents in moderate production volume; however some

integrated or hybrid operational amplifiers with special performance specifications


may cost over $100 US in small quantities. Op-amps may be packaged as components,

or used as elements of more complex integrated circuits.The op-amp is one type of

differential amplifier .

EXPERIMENT NO 2

AIM

TO STUDY AND OBSERVE OUTPUT WAVEFORM OF OP AMP IN INVERTING MODE

APPARATUS REQUIRED


digital multi meter ,

THEORY

operational amplifier can be used as inverting amplifier .in this circuit r1 i connected

between inverting input terminal of op amp. r2 is connected between inverting input

and output terminal of opamp non inverting terminal is connected to ground it will

produce phase shift of 1800 from input to output

PROCEDURE




From Function generator 1 v 1 Khz signal is applied to VIN1


VOUT =( RF/R1)VIN

OBSERVATION TABLE

Sno VIN RF RF/R1 VOUT(calculated

)

VOUT(measured ) Phase

shift

1 1 10K 1 1 1 180o

2 1 20K 2 2 1.8V 180o

3 1 30K 3 3 2.8V 180o

4 1 40K 4 4 3.5V 180o

5 1 50K 5 5 4.7V 180o

6 1 60K 6 6 5.4V 180o


RESULT

OP AMP as Inverting amplifier is studied

EXPERIMENT NO:3

AIM

Study of OP AMP as non inverting amplifier

APPARATUS REQUIRED


digital multi meter , ,

THEORY

Signal is applied to non inverting input terminal r i is connected to ground. r f is connected

between r1 and output output is measured across ouput terminal and ground output

volatge can be calculated by using equation

V OUT = (1+R F /R1 ) V IN 1

PROCEDURE




From Function generator 1 v 1 Khz signal is applied to H (non inverting input

of op amp )


Calculate tthe value of VOUT using the equation

VOUT =( RF/R1)VIN Vary the value of RF and measure the value of VOUT

OBSERVATION TABLE

Sno VIN RF 1+RF/R1 VOUT(calculated

)

VOUT(measured ) Phase

shift

1 1 10K 2 2 2 00

2 1 20K 3 3 2.5 00

3 1 30K 4 4 3.5 00

4 1 40K 5 5 4.2 00

5 1 50K 6 6 5.2 00


6 1 60K 7 7 6.2 00

RESULT

OP AMP AS NON INVERTING AMPLIFIER IS STUDIED

EXPERIMENT NO:5

AIM:

Study of transister amplifier in CE configuration

PRINCIPLE

In the bipolar transistor the most common circuit configuration for an NPN

transistor is that of the Common Emitter Amplifier and that a family of curves known

commonly as the Output Characteristics Curves, relates the Collector current (Ic),

to the output or Collector voltage (Vce), for different values of Base current (Ib).

All types of transistor amplifiers operate using AC signal inputs which alternate

between a positive value and a negative value so some way of "presetting" the

amplifier circuit to operate between these two maximum or peak values is required.

This is achieved using a process known as Biasing. Biasing is very important in

amplifier design as it establishes the correct operating point of the transistor

amplifier ready to receive signals, thereby reducing distortion to the output

signal.

We also saw that a static or DC load line can be drawn onto these output

characteristics curves to show all the possible operating points of the transistor

from fully "ON" to fully "OFF", and to which the quiescent operating point or Q-

point of the amplifier can be found. The aim of any small signal amplifier is to

amplify all of the input signal with the minimum amount of distortion possible to

the output signal, in other words, the output signal must be an exact reproduction

of the input signal but only bigger (amplified). To obtain low distortion when used

as an amplifier the operating quiescent point needs to be correctly selected. This

is in fact the DC operating point of the amplifier and its position may be

established at any point along the load line by a suitable biasing arrangement. The

best possible position for this Q-point is as close to the centre position of the

load line as reasonably possible, thereby producing a Class A type amplifier

operation, ie. Vce = 1/2Vcc. Consider the Common Emitter Amplifier circuit shown

below.


The Common Emitter Amplifier Circuit

EXPERIMENT NO :6

AIM :Study of FET amplifiers

PRINCIPLE :

a common-source amplifier is one of three basic single-stage field

effect transistor (FET) amplifier topologies, typically used as a voltage or

transconductance amplifier . The easiest way to tell if a FET is common source,

common drain, or common gate is to examine where the signal enters and leaves. The

remaining terminal is what is known as "common". In this example, the signal enters

the gate, and exits the drain. The only terminal remaining is the source. This is a

common-source FET circuit. The analogous bipolar junction transistor circuit is

the common emiter amplifier .

The common-source (CS) amplifier may be viewed as a transconductance


amplifier or as a voltage amplifier. . As a transconductance amplifier, the input

voltage is seen as modulating the current going to the load. As a voltage

amplifier, input voltage modulates the amount of current flowing through the FET,

changing the voltage across the output resistance according toOhm's law However,

the FET device's output resistance typically is not high enough for a reasonable

transconductance amplifier , nor low enough for a decent voltage amplifier .

Another major drawback is the amplifier's limited high-frequency response.

Therefore, in practice the output often is routed through either a voltage follower

(common drain or CD stage), or a current follower (common gate or CG stage), to

obtain more favorable output and frequency characteristics. The CS–CG combination

is called a cascode amplifier.

EXPERIMENT NO:7

AIM ; Study of feedback amplifiers

PRINCIPLE

A negative feedback amplifier (or more commonly simply a feedback amplifier)

is an amplifier a fraction of the output of which is combined with the input so that

a negative feed back opposes the original signal. The applied negative feedback

improves performance (gain stability, linearity, frequency response, step response )

and reduces sensitivity to parameter variations due to manufacturing or environment.

Because of these advantages, negative feedback is used in this way in many

amplifiers and control systems.A negative feedback amplifier is a system of three

elements .an amplifier with gain AOL, an attenuating feedback network with a

constant β < 1 and a summing circuit acting as a subtractor

Amplifiers use current or voltage as input and output, so four types of amplifier

are possible. See classification of amplifiers Any of these four choices may be the

http://en.wikipedia.org/wiki/Negative_feedback


open-loop amplifier used to construct the feedback amplifier. The objective for the

feedback amplifier also may be any one of the four types of amplifier, not

necessarily the same type as the open-loop amplifier.

Feedback amplifier

type

Input

connec

tion

Output

connection

Ideal feedback

Current Shunt Series CCCS

Transresistanc Shunt Shunt CCVS

Transconductance Series Series VCCS

Voltage Series Shunt VCVS

EXPERIMENT NO :8

AIM:Study of Power amplifiers

Power amplifiers are used to deliver a relatively high amount of power, usually to a low

resistance load. Typical load values range from 300W (for transmission antennas) to 8W (for audio

speaker). Although these load values do not cover every possibility, they do illustrate the fact that power

amplifiers usually drive low-resistance loads. Typical output power rating of a power amplifier will be

1W or higher. Ideal power amplifier will deliver 100% of the power it draws from the supply to load.

In practice, this can never occur. The reason for this is the fact that the components in the amplifier will

all dissipate some of the power that is being drawn form the supply. The total amount of power being

dissipated by the amplifier, Ptot , is Ptot = P1 + P2 + PC + PT + PE


The difference between this total value and the total power being drawn from the supply is the power

that actually goes to the load – i.e. output power.

Amplifier Efficiency

A figure of merit for the power amplifier is its efficiency, .

Efficiency ( of an amplifier is defined as the ratio of ac output power(power delivered to load) to dc input power .

By formula : As we will see, certain amplifier configurations have much higher efficiency ratings than others. This is primary consideration when deciding which type of power amplifier to use for a specific application.

Amplifier Classifications

Power amplifiers are classified according to the percent of time that collector current is nonzero. The

amount the output signal varies over one cycle of operation for a full cycle of input signal.

P1 = I

1

2R1

P2 = I

2

2R2

ICQ

RC

RE

R1

R2

VCC

I1

I2

ICC

PC = I

CQ

2RC

PT = I

TQ

2R

T

PE = I

EQ

2R

E

IEQ

vin

vout

Av Class-A

vin

vout

Av Class-B

vin

vout

Av Class-C


The maximum theoretical efficiency ratings of class-A, B, and C amplifiers are:

EXPERIMENT NO :9

AIM :Study of tuned amplifiers

PRINCIPLE :

1st stage is tuned RF amplifier gives some selectivity to choose

one station from many in band IF stage provides most of the

frequency slectivity

High adjacent channel selectivity Tuned IF amplifiers (multistage)

fixed tuned & provided with sufficient to reject adjacent channels.

Tuned amplifiers can be constructed from either discrete

components (FETs and BJTs) or op-amps. Discrete tuned amplifiers

normally employ LC (inductive-capacitive) circuits to determine

frequency response. Op-amps are normally tuned withRC (resistive-

99% Class C

78.5% Class B

25% Class A

Maximum Theoretical Efficiency, max Amplifier


capacitive) circuits

Tuned Amplifier Characteristics

There are many types of tuned amplifiers. A tuned

amplifier may have a lower cutoff frequency ( ), an upper cutoff

frequency ( ), or both. An ideal tuned amplifier would have zero (

) gain up to . Then the gain would instantly jump to until it

reaches , when it would instantly drop back to zero. All the

frequencies between and are passed by the amplifier. All others are

effectively stopped. This is where the terms pass band and stop

band come from. The gain of the practical tuned amplifier does not

change instantaneously,

EXPERIMENT NO: 10

AIM

To study and observe output waveform of weign bridge oscillator

APPARATUS REQUIRED

Experiment kit ,Connecting probes,c.r.o

PRINCIPLE

The weign bridge oscillator isone of the simplest and best known

oscilator and is used extensively in circuit foe audio application.this circuit

have only few components and good frequency stability.it is connected between

amplifier input terminal and output terminal the bridge has series rc network in

adjoining arm in the remaining two arms or bridge resistor r1 and rf are connected

the frequency of oscillation fo is exactly the resonant frequency of balanced weign

bridge and given by

f0= 1/2 pirc


PROCEDURE

Make connection as shown in figure

Switch on the power suply

Observe output frequency on cro

Measure output frequency

Compare it with calculated frequency

RESULT

The weign bridge oscillator is studied and waveform is observed


BHOPAL INSTITUTE OF TECHNOLOGY

DEPARTMENT

OF

ELECTRICAL & ELECTRONICS ENGG.

LAB MANUAL

OF MATLAB

(Ex406)


LIST OF EXPERIMENT

1.How to use MATLAB as a calculator

2.To Plot Elementary Function

3.To Creat simple plots

4.To plot Multiple data sets in one plot

5.To study matrix operations using matlab

6.Plot the cosine functions

7. To Plot the surface defined by the function f (x, y) = (x −

3)2 − (y − 2)2

8.To Plot the surface defined by the function f (x, y) = −xye−2(

x + y2 )


EXPERIMENT NO 1

AIM: INTROUDUCTION TO MATLAB

The name MATLAB stands for MATrix LABoratory. MATLAB was written originally

to provide easy access to matrix software developed by the LINPACK (linear system

package)

and EISPACK (Eigen system package) projects.

MATLAB is a high-performance language for technical computing. It integrates

computation, visualization, and programming environment. Furthermore, MATLAB is a

modern programming language environment: it has sophisticated data structures,

contains

built-in editing and debugging tools, and supports object-oriented programming.

These factors

make MATLAB an excellent tool for teaching and research.

MATLAB has many advantages compared to conventional computer languages (e.g.,

C, FORTRAN) for solving technical problems. MATLAB is an interactive system whose

basic data element is an array that does not require dimensioning. The software

package

has been commercially available since 1984 and is now considered as a standard tool

at most

universities and industries worldwide.

It has powerful built-in routines that enable a very wide variety of


computations. It

also has easy to use graphics commands that make the visualization of results

immediately

available. Specific applications are collected in packages referred to as toolbox.

There are

toolboxes for signal processing, symbolic computation, control theory, simulation,

optimiza-

tion, and several other fields of applied science and engineering.

Starting MATLAB

After logging into your account, you can enter MATLAB by double-clicking

on the MATLAB shortcut icon (MATLAB 7.0.4) on your Windows desktop. When you start

MATLAB, a

special window called the MATLAB desktop appears. The desktop is a window that

contains

other windows. The major tools within or accessible from the desktop are:

• The Command Window

• The Command History

• The Workspace

• The Current Directory

• The Help Browser

• The Start button

When MATLAB is started for the first

time, the screen looks like the one that shown

in the Figure 1.1. This illustration also shows the default configuration of the

MATLAB

desktop. You can customize the arrangement of tools and documents to suit your

needs.


Now, we are interested in doing some simple calculations. We will

assume that you

have sufficient understanding of your computer under which MATLAB is being run.

You are now faced with the MATLAB desktop on your computer, which contains the

prompt

(>>) in the Command Window. Usually, there are 2 types of prompt:

>> for full version

EDU> for educational version

Note: To simplify the notation, we will use this prompt, >>, as a standard prompt

sign,

though our MATLAB version is for educational purpose.

Quitting MATLAB

To end your MATLAB session, type quit in the Command Window, or select File −→ Exit

MATLAB in the desktop main menu.


EXPERIMENT NO 2

AIM: How to use MATLAB as a calculator

PROGRAMME

Basic arithmetic operators

Symbol Operation Example


+ Addition 2+3

- Subtraction 2-3

* Multiplication 2*3

/ Division 2/3

SAMPLE PROGRAMES

S no Programme Result

1 >>1+2 3

2 >>2*40 80

3 >>2/2 1

4 >>2-2 0

5 >> a=pi a = 3.1416

6 >> x=-13; y=5+x, z=x^2+y y = -8

z = 161

7 >> 1:4 1 2 3 4

8 >> 3:7

3 4 5 6 7

9 >> w = [1 -2 3] w = 1 -2 3

10 >> w' ans = 1

-2

3

11 >> x=[1+3i,2-2i] x = 1.0000 + 3.0000i

2.0000 - 2.0000i

12 >> x'

ans = 1.0000 - 3.0000i

2.0000 + 2.0000i

Result: arithmentic operations are performed

EXPERIMENT NO 3

AIM:- To Plot Elementary Function


Exercise:-To plot a graph of y = sin3πx for 0≤x≤1.

>> N=10; h=1/N; x=0:h:1;

>> y=sin(3*pi*x);

>> plot(x,y)

THEORY :-

Suppose that we want to plot a graph of y = sin3πx for 0≤x≤1. We

do this by sampling the function at a sufficiently large number

of points and joining up the points (x,y) by straight lines.

Suppose that we take N+1 points equally space a distance h

apart:

>> N=10; h=1/N; x=0:h:1; defines the set of points x=0,h,2h,....,1-h,1. The

corresponding

y-values are computed by

>> y=sin(3*pi*x); and finally, we plot the points with

>> plot(x,y)

The result is shown in the figure below where it is clear that

the value of N chosen above is too small.

On changing the value of N to 100:

>> N=100; h=1/N; x=0:h:1;


>> y=sin(3*pi*x);

>> plot(x,y)

we get the picture shown below:

To put a title and label the axes, we use

>> title('Graph of y = sin(3*pi*x)')

>> xlabel('x-axis')

>> ylabel('y-axis')

A dotted grid may be added by

>> grid

The default is to plot solid lines. A solid black line is

produced by

>> plot(x,y,'k-')

The third argument is a string whose first character specifies

the color (optional) and the second character is the line style.

The options for colors and styles are:


RESULT:

Graph is plotted


EXPERIMENT NO:4

AIM: To Creat simple plots

THEORY

The basic MATLAB graphing procedure, for example in 2D, is to take a

vector of x-

coordinates, x = (x1 , . . . , xN ), and a vector of y-coordinates, y = (y1 , . . .

, yN ), locate the

points (xi , yi ), with i = 1, 2, . . . , n and then join them by straight lines.

You need to prepare

x and y in an identical array form; namely, x and y are both row arrays or column

arrays of

the same length.

The MATLAB command to plot a graph is plot(x,y). The vectors x = (1, 2, 3, 4,

5, 6)

and y = (3, −1, 2, 4, 5, 1) produce the picture shown in Figure 2.1.

PROGRAMME:

>> x = [1 2 3 4 5 6];

>> y = [3 -1 2 4 5 1];

>> plot(x,y)


EXPERIMENT NO: 5

AIM:- To plot Multiple data sets in one plot

THEORY:

Multiple (x, y) pairs arguments create multiple graphs with a single call to plot.

For example,

these statements plot three related functions of x: y1 = 2 cos(x), y2 = cos(x), and

y3 =

0.5 ∗ cos(x), in the interval 0 ≤ x ≤ 2π.

>> x = 0:pi/100:2*pi;

>> y1 = 2*cos(x);

>> y2 = cos(x);

>> y3 = 0.5*cos(x);

>> plot(x,y1,’--’,x,y2,’-’,x,y3,’:’)

>> xlabel(’0 \leq x \leq 2\pi’)


>> ylabel(’Cosine functions’)

>> legend(’2*cos(x)’,’cos(x)’,’0.5*cos(x)’)

>> title(’Typical example of multiple plots’)

>> axis([0 2*pi -3 3])

The result of multiple data sets in one graph plot is shown in Figure 2.3.

EXPERIMENT NO:6

AIM; To study matrix operations using matlab

PROGRAMME

S

NO

OPERATION PROGRAMME RESULT

1 Entering a vector >> v = [1 4 7 10 13]

v =

1 4 7

10 13

2 >> w = [1;4;7;10;13] w =

1

4

7


10

13

3 To enter a matrix A >> A = [1 2 3; 4 5 6; 7

8 9]

1 2 3

7 8 9

4 divides the interval [0, 2π]

into 100 equal subintervals

>> theta =

linspace(0,2*pi,101)

5 To extract a submatrix B >> B = A([2 3],[1 2]) B =

4 5

7 8

6 To delete a row or column of

a matrix,

>> A(3,:) = [] A =

1 2 3

4 5 6

7 To restore the third row >> A = [A(1,:);A(2,:);[7

8 0]]

A =

1 2 3

4 5 6

7 8 0

Elementary matrices

eye(m,n) Returns an m-by-n matrix with 1 on the main diagonal

eye(n) Returns an n-by-n square identity matrix


zeros(m,n) Returns an m-by-n matrix of zeros

ones(m,n) Returns an m-by-n matrix of ones

diag(A) Extracts the diagonal of matrix A

rand(m,n) Returns an m-by-n matrix of random numbers

instructions for Matrix arithmetic operations

A+B or B+A is valid if A and B are of the same size

A*B is valid if A’s number of column equals B’s number of rows

A^2 is valid if A is square and equals A*A

α*A or A*α multiplies each element of A by α

Array operators

.* Element-by-element multiplication

./ Element-by-element division

.^ Element-by-element exponentiation

U. ∗ V produces [u1 v1 u2 v2 . . . un vn ]

U./V produces [u1 /v1 u2 /v2 . . . un /vn ]

U.ˆV produces [u1v1 u2

v2 . . . unvn]

Summary of matrix and array operations

Operation Matrix Array

Addition + +


Subtraction − −

Multiplication ∗ .∗

Division / ./

Left division \ .\

Exponentiation ˆ .ˆ

EXPERIMENT NO: 7

AIM :- Plot the following cosine functions, y1 = 2 cos(x), y2 = cos(x),


and

y3 = 0.5 ∗ cos(x), in the interval 0 ≤ x ≤ 2π.

PROGRAMME

Create a file, say example2.m, which contains the following commands:

x = 0:pi/100:2*pi;

y1 = 2*cos(x);

y2 = cos(x);

y3 = 0.5*cos(x);

plot(x,y1,’--’,x,y2,’-’,x,y3,’:’)

xlabel(’0 \leq x \leq 2\pi’)

ylabel(’Cosine functions’)

legend(’2*cos(x)’,’cos(x)’,’0.5*cos(x)’)

title(’Typical example of multiple plots’)

axis([0 2*pi -3 3])

RESULT

Programme is verified.


EXPERIMENT NO 8

AIM: -To Plot the surface defined by the function

f (x, y) = (x − 3)2 − (y − 2)2

PROGRAMME

on the domain -2 ≤ x ≤ 4 and 1 ≤ y ≤ 3.

>> [X,Y] = meshgrid(2:0.2:4,1:0.2:3);

>> Z = (X-3).^2 - (Y-2).^2;

>> mesh(X,Y,Z)

>> title('Saddle'),xlabel('x'),ylabel('y')

now repeat the previous example replacing mesh by surf.


EXPERIMENT NO;9

AIM:- To Plot the surface defined by the function

f (x, y) = −xye−2( x + y2 )

PROGRAMME

on the domain -2 ≤ x ≤ 2 and -2 ≤ y ≤ 2. Find the values and

locations of the maxima and minima of the function.

>> [X,Y] = meshgrid(-2:0.1:2,-2:0.1:2);

>> f = -X.*Y.*exp(-2*(X.^2+Y.^2));

>> figure(1)

>> mesh(X,Y,f),xlabel('x'),ylabel('y'),grid


>> figure(2)

>> contour(X,Y,f)

>> xlabel('x'),ylabel('y'), grid, hold on

To locate the maxima of the "f" values on the grid:

>> fmax = max(max(f))

fmax = 0.0920

>> kmax = find(f == fmax)

kmax = 641

1041

>> Pos = [X(kmax), Y(kmax)]

Pos = -0.5000 0.5000

0.5000 -0.5000

>> plot(X(kmax), Y(kmax),'*')

>> text(X(kmax), Y(kmax), ' Maximum')

>> hold off



LAB MANUAL

Version No. EX/5.2

Subject MICRO PROCESSOR & MICHRO CONTROLLERS

Subject Code

EX-502

Scheme New

Class/Branch

V SEM

Author Mr.Vinay Pathak



BHOPAL


DEPARTMENT

OF

ELECTRICAL

& ELECTRONICS ENGG.

LAB MANUAL

Microprocessors & Microcontroller

EX-502


LIST OF EXPERIMENTS

(1) PROGRAMMS USING MICROPROCESSOR 8086

1. ADDITION OF 2 BINARY NO OF 8 BYTE LENGTHS

2. TO FIND LARGEST NUMBER IN GIVEN STRING

3. SORT STRING OF BYTES IN DESCENDING ORDER

4. CONVERT THE STRING OF DATA TO ITS 2’ COMPLEMENT FORM

(2) PROGRAMMS USING 8051MICROCONTROLLER

5. TO FLASHING DISPLAY OF “WELCOME M51-02 KIT”

6. HEXA DECIMAL ADDITION OF TWO NUMBERS

7. STUDY OF INTER FACING CARD 8255





EXPERIMENT NO 1

AIM : PROGRAMMING USING 8086 MICCROPROCESSOR TRAINER KIT

ADDITION OF 2 BINARY NO: OF 8 BYTE LENGTHS

APPARATUS REQUIRED : MICRO PROCESSOR TRAINER KIT, KEY BOARD

PROGRAMME :

Addre

ss

Op Code Mnemonic Comments

0400 F8 CLC Clear Carry Flag

0401 B9,04,00 MOV

CX,0004

load counter register with no. of times

addition to be performed(i.e. initialize the

counterregister).

0404 BE,04,00 MOV

SI,0500

load source index reg. with

starting address of ist binary no

0407 BF,08,05 MOV

DI,0508

load destination index reg. withdest.

address (where the resultof add. is to be

started storing).

also it’s the starting address o

040A 8B,04 MOV

AX,[SI]

load data bytes (which are in location 0500

and 0501 in 16 bit acc. i.e. (0500) – ah

(0501) –

040C 11,05 ADC[DI],AX Add the contents (MS Bytes) of 0508, 0509

with the contents (lsbytes) of 0500 +0501

and store the result in location 0508

040E 46 INC SI Point at 0502 LOCN (Next rele vant source

LOCN

040F 46 INC SI Point at 0502 LOCN (Next rele vant source

LOCN

0410 47 INC DI Point at next relevant LOCN, i.e. 0504.

0411 47 INC DI Point at next relevant LOCN, i.e. 0504

0412 49 DEC CX Decrement the counter

0413 75,F5 JNE 040A If not zero (i.e. CX =0000) then continue

addition.

0415 F4 HLT Else, halt.


OBSERVATION TABLE :

BEFORE EXECUTION AFTER EXECUTION

ADDRESS INPUT DATA ADRESS INPUT DATA ADRESS OUTPUT

DATA

0500 01 0508 0A 0508 0B

0501 02 0509 0B 0509 0D

0502 03 050A 0C 050A 0F

0503 04 050B 0E 050B 12

0504 05 050C 0F 050C 14

0505 06 050D 10 050D 16

0506 07 050E 11 050E 18

0507 08 050F 12 050F 1A

RESULT :PROGRAMME IS VERIFIED .


EXPERIMENT NO:2

AIM :TO FIND LARGEST NUMBER IN GIVEN STRING

APPARATUS REQUIRED: MICRO PROCESSOR TRAINER KIT, KEY BOARD

PROGRAMME:

Address Op Code Mnemonic Comments

0400 BE,00,0

5

MOV SI,0500 load si reg:with starting address of

string

0403 B9,10,0

0

MOV CX,0010 initialize counter register with

length of string

0406 B4,00 MOV AH,00 initialize the 8 bit accumulator

0408 3A,24 CMP AH,[SI] the first data byte of the string with

00

040A 73,02 JAE 040E if both bytes match then branch to (1)

040C 8A,24 MOV AH,[SI] else move the content of (0500)into 8

bit acc i.e.a real no in ah

040E 46 INC SI point at the next address of string

040F E0,F7 LOOP NE,408 decrement the counter value if not

zero,continue processing

0411 88,24 MOV[SI],AH maximum no in 0510 address

413 F4 HLT halt

OBSERVATION TABLE :

BEFORE EXECUTION AFTER EXECUTION

ADDRESS INPUT DATA ADRESS INPUT DATA ADRESS OUTPUT

DATA

0500 01 0508 12 0510 18

0501 02 0509 18

0502 03 050A 11

0503 04 050B 0A

0504 05 050C 0B

0505 06 050D 0C

0506 07 050E 0D


0507 08 050F 0E

RESULT :PROGRAMME IS VERIFIED AND RESULT IS OBSERVED

EXPERIMENT NO:3

AIM: SORT STRING OF BYTES IN DESCENDING ORDER

APPARATUS REQUIRED :MICRO PROCESSOR TRAINER KIT, KEY BOARD

PROGRAMME :


0400 BE,00,05 MOV SI,0500 InitializeSI Register with

Memory location 0500

0403 8B,1C MOV BX,[SI] BX has the no:of bytes (to be

used for sorting )LOCNS

0500&0501

0405 4B DEC BX Decrement the no of bytes by one

0406 8B,0C(3) MOV CX,[SI] Also CX has the no of bytes in

LOCNS 0500&0501

0408 49 DEC CX Decrement the no of bytes by one

0409 BE,02,05 MOV SI,0502 Initialise SI register with the

starting address of strinf

(having data bytes )

040C 8A,04 MOV AL,[SI] Move the first data bytes of

string into AL

040E 46 INC SI Point at the next bytes of the

string

040F 3A,04 CMP AL,[SI] Compare the two bytes of string

0411 73,06 JAE 0419 If two bytes are wqual or fist

byte is above that the second

byte branch to (1)

0413 86,04 XCHG AL,[SI] Else

0415 73, DEC SI Second byte is less than first

byte and swap the two bytes

0416 86,04 MOV [SI],AL

0418 4E, INC SI Point at the next LOCN of the

string

0419 88,04 LOOP 040C Loop if CX is not zero (i.e

continue procsssing till z=0)

041B 46 DEC BX At this juncture first sorting


will be over i.e first no is

logically

041C E2,F1 MOV SI,0500 Compare with the rest of the

numbers for the correct sorting

all the numbers must be compared

with other logically i.e above

processing should be carried out

number of times

041F 4B JNZ 0406

0421 F4 HLT HALT

OBSERVATION TABLE :

ADDRESS DATA ADDRESS DATA

0500 05 0502 28

0501 00 0503 25

0502 20 0504 20

0503 25 0505 15

0504 28 0506 07

0505 15

0506 07

RESULT :PROGRAMME IS VERIFIED


EXPERIMENT NO:4

AIM :CONVERT THE STRING OF DATA TO ITS 2’ COMPLEMENT FORM

APPARATUS REQUIRED :MICRO PROCESSOR TRAINER KIT, KEY BOARD

PROGRAMME :

Address Op

Code

Mnemonic Comments

0400 BE,00,

05

MOV SI,0500 LOAD SI WITH STARTING ADDRESS OF DATA

STRING

0403 BF,00,

06

MOV DI,0600 LOAD DI WITH STARTING OF RESULT LOCNS

0406 B9,10,

00

MOVCX,0010 LOAD CX WITH THE NO OF BYTES IN STRING

0409 AC(1) LODSB LOAD AL WITH DATA BYTE ACCESSED BY SI

REGISTER AND INCREMENT THE ADDRESS

LOCN IN SI REGISTER

040A F6,D8 NEG AL THE CONTENT OF AL ARE 2 “S

COMPLIMENTED

040C AA STOSB STORE AL CONTENT IN LOCN POINTED TO BY

DI REF &INCREMENT CURRENT LOCATION IN

DI REGISTER

040D E0,FA LOOP NZ 0409 IF CX = 0000 CONTINUE 2”S

COMPLIMENTING THE DATA IN STRING

040F F4 HLT HALT


OBSERVATION TABLE :

ADDRESS

DATA

I/P

ADDR: DATA

I/P

ADDRESS DATA

O/P

ADDRESS DATA

O/P

0500 01 0508 09 0600 FF 0608 F7

0501 02 0509 0A 0601 FE 0609 F6

0502 03 050A 0B 0602 FD 060A F5

0503 04 050B 0C 0603 FC 060B F4

0504 05 050C 0D 0604 FB 060C F3

0505 06 050D 0E 0605 FA 060D F2

0506 07 050E 0F 0606 F9 060E F1

0507 08 050F 10 0607 F8 060F F0

RESULT :PROGRAMME IS VERIFIED.

EXPERIMENT NO:5

AIM :

PROGRAMMES USING MICROCONTROLLER TRAINER KIT

TO FLASHING DISPLAY OF “WELCOME M51-02 KIT”

PROGRAM:

Address Code Label Mnemonics Operand Comments

3000 90 30 1E HERE MOV DPTR#301E MESSAGE DISPLAY

3003 12 0A 3C LCALL OA36

3006 7B 00 MOV R3#0 DELAY CODE

3008 7A 00 LOOP2 MOV R2#0

300A DA FE LOOP1 DJNZ R2,LOOP1

300C DB FA DJNZ R3,LOOP2

300E 90 30 32 MOV DPTR#3032 BLANK MESSAGE

3011 12 0A 3C LCALL OA3C DISPLAY ROUTINE

3014 7B 00 MOV R3#0

3016 7A 00 LOOP4 MOV R2#0

3018 DA FE LOOP3 DJNZ R2,LOOP3 DELAY CODE

301A DB FA DJNZL R3,LOOP4


301C 80 E2 SJMP 3000 DISPLAY MESSAGE

301E 57 45 4C 43 4F

4D

DFB 57H, 45H, 4CH, 43H, 4FH, 4DH,

3024 45 20 4D 35 31

2D

DFB 45H, 20H, 4DH, 35H, 31H, 2DH

302A 30 32 20 4B 49

54

DFB 30H, 32H, 20H, 4BH, 49H, 54H,

3032 20 20 20 20 20

20

DFB 20H, 20H, 20H, 20H, 20H, 20H.

3038 20 20 20 20 20

20

DFB 20H, 20H, 20H, 20H, 20H, 20H.

303E 20 20 20 20 20

20

DFB 20H, 20H, 20H, 20H, 20H, 20H.

RESULT :MESSAGE IS DISPLAYED .

EXPERIMENT NO:6

AIM :HEXA DECIMAL ADDITION OF TWO NUMBERS

APPARATUS REQUIRED: MICRO CONTROLLER TRAINER KIT ,KEY BOARD

PROGRAMME:

ADDRESS CODE LABEL MNEMONICS OPERAND COMMENT

3000 12 0A C1 START LCALL 0AC1H READ 1ST OPERAND

3003 A3 INC DPTR

3004 E0 MOV X A@DPTR

3005 F5 0A MOV 0AH,A

3007 12 0A C1 LCALL 0AC1H READ 2ndOPERAND

300A A3 INC DPTR

300B E0 MOV X A@DPTR


300C 25 0A ADD A,0AH ADD HEX

300E 90 4E 00 MOV DPTR,#4E00H

3011 F0 MOV X @DPTR,A

3012 90 4E 00 MOV DPTR,#4E00H


3016 54 F0 ANL A,#0F0H

3018 C4 SWAP A

3019 90 4E 00 MOV DPTR#4E01H

301C F0 MOV X @DPTR,A

301D 90 4E 00 MOV DPTR,#4E00H

3020 E0 MOV X A,@DPTR

3021 54 0F ANL A#0FH

3023 90 4E 02 MOV DPTR,#4E02H


3027 12 15 58 LCALL 1558 DISPLAY RESULT

302A 90 4E 01 MOV DPTR#4E01H

302D E0 MOV X A,@DPTR

302E 12 0B 77 LCALL 0B77H GET CODE

3031 12 15 91 LCALL 1591H WRITE

3034 90 4E 02 MOV DPTR,#4E02H

3037 E0 MOV X A,@DPTR

3038 12 0B 77 LCALL 0B77H GET CODE

303B 12 15 91 LCALL 1591H WRITE

303E 12 0A A1 LP:1 LCALL 0AA1H GET KEY SPACE

3041 B4 20 FA CJNE A#20H,LP1

3044 02 30 00 LJMP START

On executing program from 3000h enter the address message displayed

,Enter the first two digit operand then press enter enter next two digit

operand sum of two numbers is displayed if sum is greater than two digit .

RESULT:HEXA DECIMAL ADDITION IS PERFORMED .


EXPERIMENT NO :7

AIM: STUDY OF INTER FACING CARD 8255

APPARATUS REQUIRED :8086 MICROPROCESSOR TRAINER KIT,KEYBOARD, INTERFACE CARD 8255.

PROGRAMME:

IN THIS PROGRAMME WE WILL BE USING 8255 IN MODE 0 WHICH IS A

SIMPLE INPUT/OUTPUT MODE HERE PORT A IS SET AS AN INPUT PORT .THE DATA WHICH IS

INPUT THROUGH PORT A WILL BE DISPLAYED ON SEVEN SEGMENT DISPLAY DEVICE THE

STATUS CAN BE VIEWED AS ON LED



0400 B0,90 MOV AL,90H INIT 8255 CWR

0402 E6,60 OUT 66H,AL SET PORT A AS

INPUT

0404 E4,60 IN AL,60H READ PORT A DATA

0406 9A,7C,F0,00,F0 CALL F000:F07C CALL CLEAR DISPLAY

040B B4,00 MOV AH,OOH MOV REG AH =00

040D B3,80 MOV BL,80H DISPLAY RAM

LOCATION OF LCD

040F 9A,94 ,F0,00,F0 F000:F094 CALL DISPLAY

ROUTINE

0414 EB,EE START JUMP TO START

OBSERVATION TABLE

STEP I:90 is the control word for 8255 in mode o using port a as input port b and

port c are not used in this experiment .

D7 D6 D5 D4 D3 D2 D1

D0

1 0 0 1 0 0 0

0

STEP II:Read the data from port a.store this data at memory location.

STEP III: Display the content of memory location on the led/lcd display of the kit

.

STEP IV: Go to start to make programe in loop so it is ready to read next data at

port a following result can be seen on LED.

DATA BUS CS RD WR

A0 A1

STEP I 90 1 0 1

1 1

STEP II DATA 1 1 0

0

RESULT :PROGRAMME IS VERIFIED .


EXPERIMENT NO: 8

AIM :STUDY OF INTER FACING CARD 8253

APPARATUS REQUIRED :SC 02,MICROPROCESSOR KIT.

PROGRAMME :


Address Op Code LABEL Mnemonic Comments

0400 B0,30 START MOV AL,30H INIT 8253

0402 E6,66 OUT 66H,AL SET FOR COUNTER 0

0404 B0,20 MOV AL,20H MOVE ACC DATA 20H

0406 E6,60 OUT 60H,AL LSB COUNT FOR COUNTER 0


040A E6,60 OUT 60H,AL LSB COUNT FOR COUNTER 0

040C B1,10 MOV CL,10H

040E FE,C9 DL1 DEC CL

0410 75,FC JNZ DL 1


0414 E6,66 OUT 66H,AL LATCH CWR COUNT

0416 E4,60 IN AL,60H READ COUNTER-0

0418 EB,E6 JMP START JUMP TO START

OBSERVATION TABLE :

DATA

BUS

CS RD WR A0 A1

START 30 1 0 1 1 1

STEP I 20 1 0 1 0 0

STEP II 00 1 0 1 0 0

STEP

III

00 1 0 1 1 1

STEP IV XX 1 1 0 0 0

STEPV AGAIN REPEAT STEP I

RESULT:8253 INTERFACING CARD IS STUDIED

EXPERIMENT NO: 9

AIM : STUDY OF INTER FACING CARD 8251

APPARATUS REQUIRED :STUDY CARD KEY BOARD,PERSONEL COMPUTER .

PROGRAMME:


THIS PROGRAMME IS TO TRANSMIT THE CHARACTER FROM PC KEY BOARD TO

8251 STUDY CARD AND THE SAME DATA WILLTRANSMITT FROM 8251 STUDY CARD TO THE PC

IN 9600 BAUD RATE THE BAUD RATE GENERATED USING 8253

ADDRESS OPCODE MNEMONICS COMMENT

0400 B0,B6 MOV AL ,B6H INIT 8253

0402 E6 06 OUT 06H,AL FOR BAUD RATE GENERATION

0404 B0,07 MOVAL,07H

0406 E6,04 OUT 04H AL LOAD LSB COUNT

0408 B0 00 MOV AL,00H

040A E6 04 OUT 04H,AL LOAD MSB COUNT

040C B0 4E MOV AL 4EH INIT MODE WORD FOR 8251

040E E6 66 OUT 86H AL OUT ON MODE WORD

0410 B0 05 MOV AL,05H MOVE ACC DATA 05H

0412 E6 66 OUT 66H,AL OUT AT COMMAND WORD

0414 E4 66 IN AL,66H

0416 24 02 AND AL,02H CHECK RECIEVER RECEIVING FLAG

0418 74 FA JZ LP2 CHECK UNTIL FLAG = 1

041A E4 60 IN AL,60H READ THE INPUT DATA (PRESSED KEY

)

041C 88 C3 MOV BL,AL MOV REG AL DATA TO BL

041E 90 NOP

041F E4 66 IN AL,66H

0421 24 01 ANDAL,01H CHECK TRANSMITTER RECEIVING FLAG

0423 74 FA JZ LP1 CHECK UNTIL FLAG =1

0425 88 D8 MOV AL,BL MOV REG BL DATA TO AL

0427 E6 60 OUT 80H,AL OUT AT DATA WORD

0429 EB E9 JMP LP2 JUMP TO LP2

RESULT :8251 STUDY CARD IS STUDIED .

EXPERIMENT NO:10

AIM :STUDY OF INTER FACING CARD 8259

APPARATUS REQUIRED :MICRO PROCESSOR TRAINING KIT,KEY BOARD, INTERFACING CARD 8259.

PROGRAMME :


0400 B8 00 00 MOV AX,0000H MOV REG AX WITH 0000H


0403 8E D8 MOV DS,AX LOAD DATA SEG AS AX

0405 B8 00 20 MOVAX,2000H INIT INTERRUPT ASSRESS

2000H

0408 89 06 00

00

MOV [0000]AX

040C B8 00 00 MOV AX,0000H

040F 89 06 02

00

MOV [0002],AX

0413 B0 17 MOV AL,17H MOV AL REG WITH DATA 17H

0415 E6 60 OUT 60H,AL ICW 1-EDGE TRIGERED

SINGLE

0417 B0 00 MOV AL,00H ICW 2

0419 E6 66 OUT66H,AL

041B B0 01 MOV AL,01 ICW4-NON BUFFERED

041D E6 66 OUT 66H,AL

041F B0 FE MOV AL,0FEH MOV ACC WIYH 0FEH

0421 E6 66 OUT 66H,AL ENABLE IR-00

0423 9A 7C F0

00 F0

CALL F000:F07C CLEAR DISPLAY

0428 B3 80 MOVBL,80H SET FIRST LINE LOCATION

RAM

042A 9A 78 F0

00 F0

CALL F000:F078 CLEAR FIRST LINE

042F B0 86 MOV AL,86H SET DISPLAY RAM LOCATION

0431 9A 44 F0

00 F0

CALLF000:F044 CALL DISPLAY

0436 0E PUSH CS

0437 1F POP DS

0438 BE 00 05 MOV SI,0500H SET MEMORY POINTER

043B B9 05 00 MOV CX,0005H COUNTER OF 5 DIGIT

DISPLAY

043E FC CLD CLEAR DIRECTION FLAG

043F AC LODSB CALL DISPLAY ROUNTINE

0440 9A 48 F0

00 F0

CALL F000,F048H LOOP TILL CX= 0

0445 E2 F7 LOOP L3

0447 FB ST1

0448 EB FE JMP HERE JUMP TO HERE

0500 48 45 4C

50 20

DB 48H, 45H ,4CH ,50H

,20H

HELP

0520 49 52 30

30 20

DB 49H, 52H, 30H 30H,

20H

IR00

INTERRUPT SERVICE ROUNTINE:



2000 9A 7C F0

00 F0

CALL F000:F07C CLEAR DISPLAY

2005 B3 80 MOV BL,80H SET FIRST LINE LOCATION RAM

2007 9A 78 F0

00 F0

CALL F000:F078 CLEAR FIRST LINE

200C B0 86 MOV AL,86H SET DISPLAY RAM LOCATION

200E 9A 44 F0

00 F0

CALL F000:F044 CALL DISPLAY RAM LOCATION

2013 0E PUSH CS

2014 1F POP DS

2015 BE 20 05 MOV SI,0520H SET MEMORY POINTER

2018 B9 05 00 MOV CX,0005H COUNTER OF 5 DIGIT DISPLAY

201B FC CLD CLEAR DIRECTION FLAG

201C AC LODSB CALL DISPLAY ROUTINE

201D 9A 48 F0

00 F0

CALL F000:F048 LOOP TILL CX=0

2022 E2 F7 LOOP L3 ICW2-NON SPECIFIC EOI

2024 B0 20 MOV AL,20H

2026 E6 66 OUT 66H,AL

2028 EB FE JMP HERE JUMP TO HERE

STEPS OF PROGRAMME FOR 8086:

STEP 1 :INITIALIZE STACK POINTER AND GIVE INITIALIZING COMMAND WORD

STEP 2 :ENABLE INTERRUPT 0 ONLY

STEP3:DELAY AND CLEAR DISPLAY

STEP 4:DISPLAY MESSAGE

THE RESULT ON LED WILL BE AS FOLLOWS :

DATA

BUS

RD WR INTA A0 CS COMMENT

STEP 1 17 0 1 0 0 1 icw 1

STEP 2 00 0 1 0 1 1 icw 2-the isr upper address

byte= 21h

STEP 3 01 0 1 0 1 1 icw 4

STEP 4 FE 0 1 0 1 1


STEP 5 FF 0 0 0 1 0 now cpu will be free runing

indicated by freshly glowing

leds and help displayed

waiting for interrupt

NOW CONNECT IR0 TO Vcc BY THE PATCH CORD

RES

ULT

:82

59

STU

DY

CAR

D

IS

STU

DIE

D .


LAB MANUAL

Version No. 1

DATA

BUS

RD WR INTA INTR A0 CS COMMENTS

STEP 1 CD 0 0 1 1 1 0 first inta cycle with cd

STEP 2 60 0 0 0 1 1 0 second inta lower adder

byte of isr

STEP 3 21 0 0 1 1 1 0 3rd inta upper address byte

of isr

STEP 4 20 0 1 0 0 0 1 ocw2 eoi

iroo will display on seven

segment

STEP 5 - - - - - - -- free running cpu

displaying”ir0”with some

delay and again display

reverts to help after

returning to main


Subject ELE. M/C -2

Subject Code

BE-503

Scheme New

Class/Branch

V SEM

Author Mr.Pajan Gangele




E.M.E.C-II Lab.


1 To Determine Equivalent circuit parameters by No load & Block

Rotor test on Single-phase induction motor.

2

V-I Characteristics of Synchronous motor

3 To perform open circuit and short circuit on a 3 phase alternator

4 To measure direct axis synchronous reactances (Xd) & Quadrature

axis synchronous reactances (Xq) of a synchronous machine.

5 To study the synchronizing of a 3-phase alternator with the bus

bar .

6 REGULATION BY SYNCRONOUS IMPEDANCE METHOD

7 V-CURVES OF SYNCHRONOUS MOTOR

8 SLIP TEST TO MEASURE STEADY STATE REACTANCES (Xd,Xq)


EXPERIMENT NO: 1

AIM: To Determine Equivalent circuit parameters by No load &

Block Rotor test on Single-phase induction motor.

INSTRUMENTS REQUIRED:

S.No

.


1 Ammeter MI 0-5A/10 A 1

2 Voltmeter MI 0-150/300 V 1

3 Wattmeter Dynamometer 5/10A,200/400

V

1

4 Lamp bank load Resistive 10 A,250 V 1

5 Techometer digital 0-2000 1

THEORY:

No load & block rotor tests are performed on 1- phase

Induction motor to determine the parameters of the equivalent

ckt.

The motor consists of a stator winding, represented by its

resistance R1 & leakage reactance X1 & two imaginary rotors

called forward & backward rotors. Exciting branch has been shown

with exciting reactance with one half the total magnetising

reactance assigned to each rotor. If forwad rotor operates at

slip S, backward rotor operates at 2S.

1. Measurement of AC resistance of stator main winding:


The DC resistance of the main winding of the stator i.e

Rdc is measured by voltmeter ammeter method at full load

current. The effective value of the resistance at line

frequency may be taken 1.1 to 1.3 times the DC voltage.

2. Parameters from block rotor test:

Using the information of block rotor test, the parameters

can be established as..

Equivalent impedance (Ze) = Vsc/ Isc.

Equivalent resistance (Re) = Wsc/ Isc.

Equivalent reactance in terms of stator, Xe = X1 +

X2’

More over X1 can be taken equal to X2’

X1=X2=1/2 Xe

Thus X2f = X2b = ½ X2’

Lly, R2f = R2b = ½ R2’

3. Parameters from No Load test:

No load equivalent impedance, Z0 = V0/ I0

Z0 = (R1+ R2’/ 4) + j(X1 + Xm/ 2 + X2’/ 2)

Cos Ф0 = W0/ V0I0


PROCEDURE :

(a). No Load test:

4. connect the ckt as shown.

5. Switch on the AC supply.

6. Adjust the voltage applied to the ckt to a low value.

7. Centrifugal switch will get open automaticlally at 75 % of

the rated speed, disconnecting the stator winding.

8. Record the applied voltage, the no load current & power

for various values of applied voltage.

9. Switch off the supply to stop the motor.

(b). Block rotor test:

4. connections are the sameexcept the meters are replaced with

proper range suggested.

5. Adjust the variac in the ckt such that its o/p voltage is

quite lowapproximately 5% to 10% of the rated voltage.

6. Switch on the ac supply.

7. Adjust the applied voltage, such that the I drawn by the

motor is full load rated current. Record the applied

voltage, I/P current & power.


8. Switch off the AC mains to stop the motor.

(c) Resistance of the main winding:

Measure the DC Resistance of the main stator winding, using the

voltmeter- ammeter method.

Observation table:

EXPERIMENT NO.02

V-I CHARACTERISTICS OF SYNCHRONOUS MOTOR

OBJECTIVE :- To study the effect of field current upon the

stator current and power factor with synchronous motor running

at no/on load , hence to draw V and inverted V-curves of the

motor.

APPARATUS REQUIRED :-

S.

No

.

Item Type Specification Quantity

1 Ammeter MI 0-10/20A 1

2 Ammeter MC 0-5/10A 1


3 Wattmeter DY 10/20A,200/400V 2

4 Voltmeter MI 0-300/600V 1


6 Voltmeter MC 0-300V 1

UNDERLYING CONCEPT :-

With constant mechanical

load on the synchronous motor, the variation of field current

changes the armature current drawn by the motor and also its PF.

As such behavior of synchronous motor is described by three

different modes of field excitation.

Normal excitation: The armature current is minimum at a

particular value of field current which is called the

field excitation. The operating PF of the motor is unity

ie it is equivalent to resistive load.

Under excitation :When the field current is decreased below

normal excitation the armature current increases and the

operating PF of the motor decreases. The PF under this

condition is lagging.

Over excitation : When the field current is increased

beyond normal excitation the armature current again

increases and the operating PF of the motor decreases.

However the PF is leading in this condition.

If the above variation of field &

armature current are plotted for a constant mechanical load a

curve of the shape V is obtained.


CIRCUIT DIAGRAM :

PROCEDURE :

14) Connect the circuit as shown in fig.

15) Switch on the supply & start the motor using starter.

16) In this case field winding is automatically excited

with the help of exciter provided on the shaft of main

motor.

17) Set rheostat in the field circuit of the motor to the

position of normal excitation . under this condition

armature will draw minimum current from the mains. Note

down readings of all the meters connected in the circuit .

18) Reduce the excitation in steps & note down the


corresponding armature current and reading of both watt

meters. Excitation may be reduced till the current in the

armature winding is of rated value. Under this condition

armature should increase on reducing the excitation .

19) Again adjust the rheostat in the field circuit to

normal excitation .Now increase the excitation in steps

and note down the reading of all the meters at each setting

of increase excitation .

20) Adjust the voltage of dc generator coupled to

synchronous motor to rated value by varying the field

current of the generator.

21) Load the DC generator to half load /Full load & repeat

steps 4,5,6.

22) Remove the load on the dc generator gradually.

10 . Switch off the supply .

OBSERVATION TABLE :-

S.No V If Ia W1 W2 Vdc Idc COSФ

1

2

3

4

5

RESULT:-


CONCLUSION:-

EXPERIMENT NO.: 03

OBJECTIVE :-

(a) perform open circuit and short circuit on a 3 phase

alternator

(b) Perform load test on 3 phase alternator with highly lagging

load (approximately zero power factor ) and at rated voltage

with rated current flowing in the stator winding

(b) Draw open circuit and zero power factor saturation

characteristics of the alternator on the same graph .

(c) Calculate the regulation of alternator by drawing the

proper phasor diagram connected with the above characteristics

.


S.No Item Type Range Quantity

1 Ammeter MI 0-10/20 A 1

2 Ammeter MC 0-2.5/5 A 1

3 Voltmeter MI 0-300/600

V

1

4 Rheostat Single 272 , 1.7 1


tube A

5 Rheostat Single

tube

300 2.2 A 1

6 3 Phase Highly

inductive load

Lagging 15 A ,400

V

1

7 Tachometer Digital 0-2000 rpm 1


Zero power factor saturation curve

method is most reliable for determining the regulation of

alternator , because it properly takes into account , the effect

of armature leakage reactance drop and the saturation .The

following experimental data is needed to determine the

regulation by this method .

Open circuit characteristics at the rated speed of the

alternator .

Field current corresponding to full load short circuit

current i.e. only one reading of short circuit test .

Field current corresponding to full load rated voltage zero

power factor i.e. again only one reading of zero power

factor full load characteristics.

AC resistance of the stator winding per phase of the

alternator .


Plotting of zero power factor , full load characteristic:-

To plot zero power factor full load characteristic from the

experimental data proceed as follows

(yyy) Draw the open circuit characteristic to proper scale

and also draw the air gap line

(zzz) Draw the field current , If sc corresponding to full

load short circuit current ,This has been represented by the

line OB in fig .

(aaaa) Draw the field current If Zp at rated voltage (line

TP) which correspond to full load zero power factor thus

obtaining a point P on the zero power factor full load

characteristic.

(bbbb) From the point P draw a horizontal line PC

representing the field current corresponding to full load

short circuit current i.e. PC = OB .

(cccc) From the point C draw a line CD parallel to air gap

line .

(dddd) Join D to P Now PCD is a triangle which is normally

called as Potier triangle .

(eeee) Points P’ and P” on the zero power factor full load

curve can be obtained by tracing the Potier triangle as shown

in fig.


(ffff) Zero power factor full load characteristic can now be

drawn from the points B, P’, P” and P, which are in this

characteristics .

DETERMINATION OF LEAKAGE REACTANCE

Drop a perpendicular from the point D

meeting the PC at the point E then line ED represents the

leakage reactance drop which is also called as Potier reactance

drop (Ez )

DETERMINATION OF REGULATION

Regulation of alternator can be determined following the

various steps given below .

4. Draw the current phasor , Ia horizontally which is a

reference phasor , fig

5. Terminal voltage phasor V (line OA) is drawn at power factor

angle with respect to current .

6. Add armature resistance drop Ia Ra (line AB) to the terminal

voltage phasor V.

7. Potier reactance drop Ex is added in quadrature to the


current phasor.(line BC)

8. Join O and C , line OC represents the internally generated

emf. Eg.

9. Phasor OA and OC are projected by arc to the vertical line .

10. Intercept DE shown by dotted horizontal line in fig

represents the field current Ifg corresponding to no load

rated voltage .

11. The portion GH to the intercept FH represents the field

current Ifs which takes into account the effect of

saturation .

12. Draw the field current Ifg horizontally (line OS) a shown

in fig.

13. Add the field current Ifsc (line ST) at power factor angle

with the vertical as shown in fig.

14. Join OT and the field current Ifs (line TU) thus giving a

total field current If.

15. No load emf Eo corresponding to field current , I is found

out from the open circuit characteristic

Then regulation = E− V

V× 100 percent

CIRCUIT DIAGRAM :-


Fig shows the circuit diagram for conducting open circuit and

short circuit tests on 3 phase alternator which have already

been explained in art gives the circuit diagram for performing

load test (with highly inductive load ) on the alternator .the

following instruments connected in the circuit serve the

function indicated against each .

1.Rheostat R1 –to vary the field current of dc motor coupled

with alternator to adjust and maintain the rated speed of

alternator .

2. 3 Phase highly inductive load – to load the alternator at

rated current and at approximately zero power factor .

3. Ammeter , A – to record the load current of alternator .

4. Voltmeter – to measure phase voltage of the alternator .

5. Rheostat R2 –to vary the field current of alternator so as to


obtain rated voltage at full load .

6. Ammeter A1- to record field current of alternator

PROCEDURE.

For zero power factor test :-

12. Connect the circuit as per figure .

13. Set the rheostat R1 so that the field current of the motor

is maximum possible at the instant of starting the motor

(fully out of field circuit ).

14. Set the rheostat R2 so that the field current of

alternator is minimum .

15. Ensure that the alternator is on no-load.

16. Switch on the dc supply and start the dc motor with the

help of starter .

17. Vary the field current of the motor by rheostat R1 so as

to obtain rated speed .

18. Switch on the dc supply to the field of the alternator .

19. Vary the field current of the alternator gradually in

steps and adjust the rated terminal voltage across the load

at each step by increasing the field current till full load

of the alternator .Record field current of the alternator


.The complete zero power factor characteristics can be

plotted based in one reading only.

20. Decrease the load on the alternator gradually and side by

side , reduce the field current of the alternator .

21. Switch off the dc supply to the field of the alternator

and dc motor .

22. Measure the dc resistance of the stator phase by

voltmeter .ammeter method and convert it to ac resistance

by multiplying the same with a factor 1.3 which takes into

account the skin effect ..

OPEN CIRCUIT AND SHORT CIRCUIT TEST :

Procedure for open circuit and

short test on alternator has already been explained in

experiment -01 , which may be referred for performing these

tests.

OBSERVATION : May be tabulated as follows :

(a) For ZPF Test

S.No Stator current Terminal

voltage

Field current


For open and short circuit test

Open circuit test Short circuit test

S.No Field

current

E.M.F. S.N

o

Field

current

Short circuit

test

RESULT :-

CONCLUSION:-

EXPERIMENT NO:04

AIM: To measure direct axis synchronous reactances (Xd) &

Quadrature axis synchronous reactances (Xq) of a synchronous


machine.

INSTRUMENTS REQUIRED:

THEORY:

Xq & Xd are the steady state reactances of the synchronous

machine.

(gggg) Direct axis synchronous reactance, Xd :

Xd of a syn. machine in per unit is equal to

the ratio of field current, Ifsc at the rated armature current

from the short circuit test, to the field current, Ifo at the

rated voltage on air gap line.

Direct- aixs synchronous reactance, Xd = Ifsc / Ifo

per unit.

(ii) Quadrature axis synchronous reactance, Xq by slip

test :

For the slip test, the alternater should

be driven slightly les than the synchronous speed with its field

current open. 3 phase balanced voltage of rated frequency is


applied to armature (stator) terminals. Now in the wave graph,

when the crest of the stator mmf wave coincides with the direct

axis of the rotating field, the induced emf in the open field is

zero, the voltage across the stator terminals will be maximum &

the current drawn by the stator winding is minimum.

Thus, approximate value of Xd :

(Xds) =Emax / Imin

When the crest of the stator

mmf wave coincides with the quadrature axis of the rotating

field, the induced emf in the open field is maximun, the voltage

across the stator terminals will be minimum & the current drawn

by the stator winding is maximum.

hus, approximate value of Xq :

(Xqs) =Emin / Imax

Now, the Quadrature- axis synchronous reactance, Xq = Xd (Xqs /

Xds) = Xd [Emin / Imax][Emax / Imin ] per unit.

Note: For synchronous machines, Xd is greater than Xq

i.e Xd > Xq .

PROCEDURE:

(a). open ckt test:

connect the ckt.

Swith on dc supply to dc motor & the field of

alternator.

Start the dc motor with the help of starter.

The starter arm should be moved slowly, till the speed

of the dc motor builds up & finaly all the resistance steps

are cut out & the starter arm is held in on position by the

magnet of no volt releasse.


Record the field current of the alternator & its open

ckt voltage per phase.

Increase the field current in steps by decreasing the

resistance & record the field current & open ckt voltage of

the alternator for various values of field current.

Increase the field current upto 30 % higher than the

rated voltage.

Now Decrease it to minimum by inserting rheostat fully

in field ckt.

(b). short ckt test :

with the dc motor running at rated speed & with

minimumfield current of alternator, close the switch s,

thus short-ckting the stator winding of alternator.

Record the field current of the alternator & the short ckt

current.

Increase the field current till the rated full load short-

ckt current.

Take 4-5 observations.

Decrease the field curent of alternator to minimum & also

decrease the speed of dc motor by field rheostat of the

motor.

13. Switch off the dc supply.

(c). slip test :

23) connect the ckt.

24) Keep the resistance in the field current of the dc

motor minimum.

25) switch on dc supply & repeat the step in (a).

26) Ensure that the setting of 3-phase variac is at zero

position.

27) Switch on 3-phase ac supply to the startor winding of

alternator.

28) Ensure the direction of rotation of alternator, when

run by dc motor & when by 3-phase induction motor is the


same.

29) Adjust the voltage applied to the stator winding, till

the current in the stator winding is approx full load rated

value.

30) Reduce the applied voltage & switch off the ac supply.

31) Decrease the speed of dc motor & switch off dc supply.

Observation table :

EXPERIMENT NO :-05

SYNCHRONISATION OF ALTERNATOR

OBJECTIVE :- To synchronise a 3 phase alternator with the bus

bar .


S.No Name Type Range Quantity


2 Rhesostat Single tube Consisting

of 3 set of bulbs and

290 Ω1.7 A

2


a 3 phase switch

3

Synchronisin

g

Switch board

---------------

-

290 Ω1.7 A

1

UNDERLYING CONCEPT:-

A single generating station normally consist of several ac

generators to supply the total load on the station .During light

load on the station only a few generators are operated to supply

the demand .When the load on the station increases heavily other

ac generators are also to be operated to run in parallel with

the existing generator in order to cope up the increased load on

generating station.

Synchronising of ac generators is the process of

switching on an incoming alternator to the bus bar so that it

can operate in parallel with other alternators already connected

to the bus bar to share the load on the generating station.

Before an incoming alternator can be synchronised to the bus

bars the following conditions must be fulfilled .

a) The voltage generated by the incoming generator

is equal to the bus bar voltage .It is advisable

to check this condition using the same voltmeter

for measuring both the voltage .

b) The phase sequence of the generated voltage of

incoming alternator is the same as that of bus

bar voltage.

c) The frequency of the generated voltage of

incoming alternator is the same as the bus bar

frequency .

Condition (i) can be satisfied by equalising the two voltage

which are indicated by a voltmeter .Other conditions of

synchronisation are indicated by a synchroscope and by lamp


method .Before using any one of the above method to ascertain

condition (ii) and (iii) the speed of the incoming alternator

is adjusted to its rated value by varying the field current of

the dc motor which is the prime mover for this alternator .

Synchronoscope is a device by means of which we can correctly

detect the frequency or the speed the incoming alternator with

respect to the busbar .The device is fed by the generated phase

voltage of incoming alternator on one side and by the bus bar

phase voltage on the other side .It clearly indicates by a

pointer whether the incoming alternator is running fast or slow

.As per the indication obtained by this device the speed of the

alternator can be increased or decreased as the case may be to

equalise the frequency to this alternator with that of bus bar.

To indicate the correct equalization of frequency and the same

phase sequence of incoming alternator and bus bar lamp

synchronizing or bright lamp synchronising are generally used

in laboratories .In dark lamp method of synchronizing all the

three sets of bulbs become dark at the same time and at a

different instant become bright at the same time .The three sets

of lamps are connected directly across the R-R’ , Y-Y’ , and

B-B’ phase of incoming alternator and that of bus bar , so that

synchronizing of incoming alternator is carried out while all

the three sets of lamps are dark .This method of synchronizing

is preferred , because it is easier to; judge the instant of

the bright period than the instant of dark period at the time

of synchronizing .Hence bright lamp method is commonly used for

synchronizing the incoming alternator with the bus bar .

In bright lamp method one set of lamp is directly

connected between the similar phases of incoming alternator and

bus bar where as other two sets of lamps are cross connected

between the phases of incoming alternator and bus bar as shown

in fig ., so that at the instant of synchronizing one set of

lamp which is directly connected would be dark while the other


two sets should be equally bright .In this set of synchronising

if the frequency of the alternator and the bus bar are not

equal , lamp will flicker the alternation is brightness being

rapid when there is a large difference in frequencies and slow ,

when the frequencies are nearly equal .Hence the speed of the

incoming alternator is adjusted until the set of lamps go in and

out very slowly This method gives a clear indication of the same

phase sequence also that of the voltage of alternator and of bus

bar .

CIRCUIT DIAGRAM :-

Fig

sho

ws

the

cir

cui

t

diagram for synchronising an alternator with the bus bar .The

prime mover of the alternator is dc motor whose speed can be

adjusted bu the rheostat provided in its field circuit .The

generated voltage of the alternator is adjusted equal to the bus

bar voltage by varying the field current of alternator with the

rheostat provided in its field circuit .Synchronising switch

board consisting of three set of lamps (each set with 2 lamps in

series ) and a switch forms the proper link between the


incoming alternator and the bus bar .

PROCEDURE ;-

1. Connection are made as per circuit diagram.

2. ensure that the synchronising switch is open ,

external resistance in the field circuit of the motor

is zero and external resistance in the field circuit

of alternator is maximum.

3. Switch on dc supply to the dc motor and start it using

the starter.

4. Adjust the speed of the dc motor to rated speed of

alternator by varying the rheostat in its field

circuit .

5. Switch on the dc supply to the field of the

alternator and adjust the field current so that the

generated voltage of the alternator is equal to the

bus bar voltage .

6. Switch on the bus bar voltage .Now the three set of

lamps will flicker .In case flickering is fast adjust

slowly the speed of the incoming alternator , so that

its frequency become equal to the bus bar frequency

.Check the equality of two voltage that of alternator

and bus bar again. Under such condition the set of

lamps will of in and out very slowly

7. Observe that the phase sequence of the alternator is

the same as that of bus bar which can be checked by

the order of the sets becoming dark and bright .As per


the connection of the set of lamps , one set which is

directly connected between the same phase should be

dark and at the same instant the other two set of

lamps which are cross connected should be bright

8. Watch for the correct instant of sychronising switch

in hand and close this switch when the directly

connected set of lamps is dark and the other two set

of lamps are equally bright thus synchronizing the

incoming alternator with the bus bar .

9. Switch –off the synchronizing switch , bus –bar switch

and then the dc main to stop the dc motor and the

alternator .

EXPERIMENT NO :- 06

REGULATION BY SYNCRONOUS IMPEDANCE METHOD

OBJECTIVES :-

(a) Perform, no load and short circuit tests on a 3 phase

alternator .

(b) Measure the resistance of the stator winding of

alternator .

(c) Find out regulation of alternator at full load and at (i)

unity p.f. (ii) 0.85 p.f. lagging (iii) 0.85 p.f. leading ,

using synchronous impedance method .


PREREQUISITE :-


UNDERLYING CONCEPT:-

To find out the regulation of

alternator by synchronous impedance

method , following characteristics and data has to be

obtained experimentally ,

9. open circuit characteristics at synchronous speed.

10. Short circuit characteristics at synchronous speed.

(iii) Ac resistance of the stator winding per phase i.e.

Ra .

Figure shows the open circuit and short circuit

S.No

.


1 Ammeter MC 0-1/2 A 1

2 Ammeter MI 0-10/20 A 1

3 Voltmeter MI 0-300/600 V 1

4 Rheostat Single

tube

272, 1.7 A 2

5 Tachometer Digital 0-2000 rpm 1


characteristics of a 3 phase

alternator plotted on the phase . To find out the synchronous

impedance from these characteristics open circuit voltage , E1

and short circuit current I1 (preferably full load current ) ,

corresponding to a particular value of field current is obtained

.Then synchronous impedance per phase is given by,

Synchronous impedance , ZO = E1/I1

Then , Synchronous reactance , Xs = Zs –Rs

Figure shows the phasor diagram of the alternator supplying full

load current of Is ampere lagging the terminal voltage V by an

angle .The open circuit voltage E of the alternator is given by

E = V +IaRa

+IsXs (Phasor sum)

The diagram has been drawn with the current as the reference

phasor and is self explanatory .The open circuit voltage is

finally obtained from the phasor diagram corresponding to this

loading condition is E volts .Then the regulation of the


alternator under the above loading condition is given by

Regulation =

E− V

V× 100 percent

An approximate expression for the open circuit voltage can be

established referring to the phasor diagram

Open circuit voltage , E = (OD +DC)

= ( OF +FD) +(DB +BC)

or E = (V cos +IaRa ) + (V sin +Ia

Xa ) (for lagging p.f. load )

The above expression is lagging power factor load .In case

alternator is operating at leading power factor open circuit

voltage , E can be found out in a similar way and is given by ,

E = (V cos +IaRa ) –(Vsin + IaXa )

(for lagging p.f. load )

The value of regulation obtained by this method is higher than

obtained from as actual load test , as such it is called the

pessimistic method .

CIRCUIT DIAGRAM :-


It is essential to include the following equipments

/instruments of proper type and range to serve the function

indicated against each ,

4. DC motor – used as a prime –mover for the alternator i.e.

coupled with the alternator

5. Rheostat R1 – used as a variable resistance and connected

in the field circuit of dc motor to obtain and maintain the

speed of the motor and hence the alternator .

6. Rheostat R2 – connected in field circuit of alternator as a

variable resistance to vary the field current of alternator

.

7. Ammeter A1 – connected in the field circuit of alternator

to measure the field current

8. Voltmeter – Connected across a stator phase to measure open

circuit voltage .

9. Ammeter A2 – To measure the short circuit current of


alternator

Complete circuit diagram drawn on the basis of above

discussion has been shown figure.

PROCEDURE :

Connect the circuit as per figure.

Adjust the position of rheostat R1 for maximum possible

current in the field circuit of dc motor to ensure (i) low

starting speed (ii) high starting torque

Set the position of rheostat R2 for minimum current in the

field circuit of alternator to ensure low value of

generated emf at starting .

Switch on the dc main feeding the dc motor and the field

circuit of alternator .

Start the dc motor using the starter properly .Various

resistance steps of the starter should be cut out slowly so

that the motor does not draw high current during starting

Set the speed of the motor and hence the alternator at its

rated speed value by varying rheostat R1 provided in the


field circuit of motor .

Note down the open circuit voltage of the alternator and

the field current .

Repeat step 7 for various value of field current (can be

obtained by varying the rheostat R2 provided in the field

circuit of the alternator ).Observation should be contained

till the open circuit voltage is 25 to 30 percent higher

than its rated value

Set the position of rheostat R2 again for minimum possible

current in the field circuit of alternator .

Short circuit the stator winding of the alternator , by

closing the switch provided for this purpose in the circuit

diagram.

Note down the short circuit current and the field current .

Repeat step 11 for various value of field current till the

short circuit current becomes equal to the full load

current of alternator .

Readjust the setting of rheostat of rheostat R1 and R2 to


their initial position and then switch off the dc supply to

stop the dc motor .Measure the dc resistance of the

stator winding by usual voltmeter ammeter method .To obtain

ac resistance skin effect must be taken into account .As

such ac resistance may be taken approximately 1.3 times the

dc resistance measured.

OBSERVATION : May be tabulated as follows.

Open circuit voltage

Short circuit

voltage

S.No If E If Isc

RESULT:-

CONCLUSION :-


EXPERIMENT NO.07

V-CURVES OF SYNCHRONOUS MOTOR

OBJECTIVE :- To study the effect of field current upon the

stator current and power factor with synchronous motor running

at no/on load , hence to draw V and inverted V-curves of the

motor.


S.

No

.


1 Ammeter MI 0-10/20A 1


3 Wattmeter DY 10/20A,200/400V 2



6 Voltmeter MC 0-300V 1


With constant mechanical

load on the synchronous motor, the variation of field current

changes the armature current drawn by the motor and also its PF.

As such behavior of synchronous motor is described by three

different modes of field excitation.

Normal excitation: The armature current is minimum at a

particular value of field current which is called the

field excitation. The operating PF of the motor is unity


ie it is equivalent to resistive load.

Under excitation :When the field current is decreased below

normal excitation the armature current increases and the

operating PF of the motor decreases. The PF under this

condition is lagging.

Over excitation : When the field current is increased

beyond normal excitation the armature current again

increases and the operating PF of the motor decreases.

However the PF is leading in this condition.

If the above variation of field &

armature current are plotted for a constant mechanical load a

curve of the shape V is obtained.

CIRCUIT DIAGRAM :


PROCEDURE :

32) Connect the circuit as shown in fig.

33) Switch on the supply & start the motor using starter.

34) In this case field winding is automatically excited

with the help of exciter provided on the shaft of main

motor.

35) Set rheostat in the field circuit of the motor to the

position of normal excitation . under this condition

armature will draw minimum current from the mains. Note

down readings of all the meters connected in the circuit .

36) Reduce the excitation in steps & note down the

corresponding armature current and reading of both watt

meters. Excitation may be reduced till the current in the

armature winding is of rated value. Under this condition

armature should increase on reducing the excitation .

37) Again adjust the rheostat in the field circuit to

normal excitation .Now increase the excitation in steps

and note down the reading of all the meters at each setting

of increase excitation .

38) Adjust the voltage of dc generator coupled to

synchronous motor to rated value by varying the field

current of the generator.

39) Load the DC generator to half load /Full load & repeat


steps 4,5,6.

40) Remove the load on the dc generator gradually.

10 . Switch off the supply .

OBSERVATION TABLE :-

S.No V If Ia W1 W2 Vdc Idc COSФ

1

2

3

4

5

RESULT:-

CONCLUSION:-

EXPERIMENT NO

:-8

SLIP TEST TO MEASURE STEADY STATE REACTANCES (Xd,Xq)

OBJECTIVES :

(a) To measure direct axis synchronous machine.

(b) To measure quadrature- axis synchronous reactance

by slip test.



S.NO

.


1 Ammeter MI 0-15 A 1

2 Ammeter MC 0-2A 1

3 Voltmeter MI 0-150V 1

4 Voltmeter MI 0-600V 1

5 3-phase variac - 400/0-

400V,15A

1

6 Rheostat Single

tube

272Ω, 1.7A 2

UNDERLYING CONCEPT:

Direct-axis synchronous reactance and quadrature-axis

synchronous reactance are the steady state reactances of the

synchronous machine. These reactances can be measured by

performing, open circuit, short circuit tests and the slip test

on a synchronous machine.

4. Direct- axis synchronous reactance of synchronous machine

in per unit is equal to the ratio of field current Ifac

at rated armature current from the short circuit test,

to the field current, I,fo at rated voltage on the air

gap line.

Direct-axis synchronous reactance, Xd = Ifac

Ifo

Thus direct-axis synchronous reactance can be found out by

performing open circuit and short circuit test on an alternator.


5. Quadrature-axis synchronous reactance, Xq by slip test:

For the slip test, the alternator should be driven at a speed,

slightly less than the synchronous speed with its rated

frequency is applied to armature (stator) terminals of the

synchronous machine. Applied voltage is to be adjusted, so that

the current drawn by the stator winding is full load rated

current. Under these conditions of operation, the variation of

the current drawn by the stator winding, voltage across the

stator winding and the voltage across the field winding will be

as shown in fig. The wave shapes of stator current and stator

voltage clearly indicate that these are changing between minimum

and maximum values. When the crest of the stator mmf wave

coincides with the direct axis of the rotating field, the

induced emf in the open field is zero, the voltage across the

stator terminals will be maximum and the current drawn by the

stator winding is minimum as shown in fig. Thus approximate

value of direct-axis synchronous reactance, Xds is given by,

Xds = Emax

Imin

When the crest of stator wave coincides with the quadrature-axis

of the rotating field, the induced emf in the open circuit field

is maximum, the voltage across the stator terminals will be

minimum and the current drawn by the stator winding is maximum

as shown in qudrature- axis synchronous reactance ,Xqs is given

by, Xqs is given by,

Xqs= Emin

Imax

For best results, these values are not taken as final values.

The most accurate method for determining the direct axis

synchronous reactance, Xd is the one, that has already been

described in (i) above. The most accurate value of qudrature-


axis synchronous reactance, Xq can now be found out using the

above information i.e Xds, Xqs and Xd.

Quadrature –axis synchronous reactance ,Xq = Xqs Xd

Xds

= [Emin] [Imax ] Xd per unit.

Imax Emin

Hence the accurate value of Xq can be found out by recording

minimum and maximum values of the above quantities.Accurate

results can be obtained, if the oscillograms are taken during

experimentation for statorv current,stator voltage and injected

voltage across the field.

It may be noted that for synchronous machine,Xd is greater than

Xq i.e. Xd >Xq.

Important caution for conducting slip test

9. Slip should be extremely low during experimentation. In

case of high slip (more than about 50%), following effects

may be observed.

6. Currents induced in the damper winding of alternator will

produce an appreciable error.

7. Induced voltage in the damper winding of alternator will

produce an appreciable error.

10. It should be assured that the induced voltage in the

field circuit is less than the rating of the voltmeter

connected in this circuit.

CIRCUIT DIAGRAM:-


Fig(10.4) and (10.13) show the circuit diagrams to perform the

open circuit, short circuit and slip test respectively on

synchronous machines, which are self explanatory. Fig. (10.40

has already been given in art, 10.5 and hence not repeated.

PROCEDURE :-

open circuit test

11. Connect the circuit as per fig. (10.4).

12. Ensure that the external resistance in the field of dc

motor acting as a primover for alternator is minimum and

the external resistance in the field circuit of alternator

is maximum.

13. Switch on dc supply to dc motor and the field of

alternator.

14. Start the dc motor with the help of starter. The

starter arm should be moved slowly, till the speed of the


motor builds up and finally all the resistance steps are

cut out and the starter arm is held in on position by the

magnet of no volt release.

15. Adjust the speed of the dc motor to rated speed of the

alternator by varying the external resistance in the field

circuit of the motor.

16. Record the field current of the alternator and its

open circuit voltage per phase.

17. Increase field current of alternator in steps by

decreasing the resistance and record the field current and

open circuit voltage of alternator for various values of

field current.

18. Field current of alternator is increased, till the

open circuit voltage of the alternator is 25 to 30 percent

higher than the rated voltage of the alternator.

19. Decrease the field current of alternator to minimum by

inserting the rheostat fully in the field circuit.

Short circuit test

20. With the dc motor running at rated speed and with

minimum field current of alternator, close the switch s,

thus short-circuiting the stator winding of alternator.

21. Record the field current of alternator and the short

circuit current.

22. Increase the field current of alternator in steps,

till the rated full load short-circuit current. Record the

readings of ammeters in both the circuit at every step. 4

to 5 observations are sufficient, as short circuit

characteristic is a straight line.

23. Decrease the field current of alternator to minimum

and also decrease the speed of dc motor by field rheostat

of the motor.

24. Switch off the dc supply to dc motor as well as to

alternator field.


c) Slip Test

6. Connect the circuit of alternator as shown in fig.(10.13),

keeping the connections of the dc motor same.

7. Ensure that the resistance in the field circuit of dc motor

is minimum.

8. Switch on the dc supply to the motor.

9. Repeat steps 4 described in (a).

10. Adjust the speed of the dc motor slightly less than

the synchronous speed of the alternator by varying the

resistance in the field circuit of the motor. Slip should

be extremely low, preferably less than 4 percent .

11. Ensure that the setting of 3 phase variac is at zero

position.

12. Switch on 3 phase ac supply to the stator winding of

alternator.

13. Ensure that the direction of rotation of alternator,

when run by the dc motor and when run as a 3 phase

induction motor) is the same.

14. Adjust the voltage applied to the stator winding, till

the current in the stator winding is approximately full

load rated value.

15. Under these conditions, the current in the stator

winding, the applied voltage to the stator winding and the

induced voltage in the open field circuit will fluctuate

from minimum values to maximum values, which may be

recorded by the meters included in the circuit. For better

results, oscillogram may be take of stator current, applied

voltage and induced voltage in the field circuit.

16. Reduce the applied voltage to the stator winding of

alternator and switch off 3 phase ac supply.


17. Decrease the speed of dc motor and switch off dc

supply.

OBSERVATIONS: May be tabulated as follows:

Open circuit

test Short circuit test Slip test

S.

No. Ir Vo If Iac Imin Imax Vmin Vmax

RESULT :-

CONCLUSION:-


BHOPAL INSTITUE OF

TECHNOLOGY

LAB MANUAL

Version No. POWER ELECTRONIC (EX-504)

Subject POWER ELECTRONIC (EX-504)

Subject Code

EX-504

Scheme New

Class/Branch

I & II Semester / all

Author REETA PAWAR



POWER ELECTRONIC

EXPERIMENT :- 1

STATIC CHARACTERISTICS OF SCR

Aim : Study static characteristics of SCR.

Apparatus Required:

Sl. No. Components Quantity Range

1. Connecting wires 1 -

2. SCR module 1 -

Procedure :

A variable DC power supply, using LM 317 regulator to vary the Anode voltage from 2.5

Volts to

35 volts approximately. One more variable DC power supply using LM 317 regulator to

vary the

Gate Voltage from 1.5 volts to 15 volts approximately. Switch and fuse is provided in

series with

both the power supplies. A potentiometer of 25 watts is provided to vary the load

current. A

potentiometer of 3 watts is provided to vary the Gate current. A Digital Voltmeter is

provided to

measure the Voltage. Two digital Ammeters are provided to measure Anode current and

Gate

current.

Definitions:-

Holding Current (IH): Minimum value of anode current below which the current must

fall for turning Off the SCR.

Latching Current (IL): Minimum value of anode current that SCR must attain during

turn On process to maintain conduction when gate signal is removed. Latching current

is two to three times higher than holding current.

Ckt Diagram:


Proced

ure:

1. Set

VG to

minimu

m,

adjust

Vak to

VA –

10

Volts.

1. To

find

IG:

2. Slowly increase VG till SCR conducts. Note down the corresponding IG.

3. Repeat the procedure 2-3 times to accurately get the IG values

1. Make the connections as given in the circuit diagram including meters for SCR

1.

2. V – I Characteristics:

2. Now switch ON the mains supply to the unit and initially keep VA &VG at

minimum.

3. Set load potentiometer R1 in the minimum position. Adjust IG to the value

found

in procedure 1.

4. Slowly vary VA and note down Vak and IA readings for every 5 Volts and

entered

the readings in the tabular column. Further vary VA till SCR conducts, this

can be

noticed by sudden drop of Vak and rise of IA readings note down this

readings

and tabulate. Keep multi meter in mili-volts range and connect across VA

terminals. Note down the variation of IA for small variations in VA.

5. Draw the graph of Vak v/s IA. Repeat the same for IG=IG2 /IG3 and draw the

graph.

3. To find latching current:

1. Apply about 20 V between Anode and Cathode by varying VA. Keep the load

potentiometer R1 at minimum position. The device must be in the OFF state

with

gate open.

2. Gradually increase Gate voltage - VG till the device turns ON. This is the

minimum gate current (Igmin) required to turn ON the device.

3. Adjust the gate voltage to a slightly higher.

4. Set the load potentiometer at the maximum resistance position. The device


should comes to OFF state, otherwise decrease VA till the device comes to OFF

state. The gate voltage should be kept constant in this experiment.

5. By varying R1, gradually increase load current IA in steps. Open and close the

Gate voltage VG switch after each step. If the anode current is greater the

latching current of the device, the device stays on even after the gate

switch is

opened. Otherwise the device goes into blocking mode as soon as the gate

switch

is opened. Note the latching current.

6. Obtain the more accurate value of the latching current by taking small steps

of IA

near the latching current value.

4. To find holding current:

1. Increase the load current from the latching current level by load pot R1 or

VA.

2. Open the gate switch permanently. The Thyristor must be fully ON.

3. Now start reducing the load current gradually by adjusting R1. If the SCR does

not turns OFF even after the R1 at maximum position, then reduce VA. Observe

when the device goes to Blocking mode. The load current through the device at

this instant is the holding current of the device.

4. Repeat the steps again to accurately get the Ih. Normally Ih < Il.

5. Repeat the same procedure for other SCR – SCR 2. Note down the different

ratings of both the devices.

Tabular Column:

a) V-I Characteristics Reading

Sl. No V AK IA V AK IA

b) IG = ______________ mA

c) Latching Current Il = ______________ mA

d) Holding Current Ih = _______________ mA


Result:

Static characteristics of SCR are determined.

EXPERIMENT 2 &3 :

STATIC CHARACTERISTICS OF MOSFET AND IGBT

Aim: To study the static characteristics of MOSFET and IGBT.

Apparatus Required:

Sl. No. Components Quantity Range

1. External meters 1 -

2. Connecting wires 1 -

3. IGBT/MOSFET module 1 -

Details of the module: This unit mainly consists of the following Power

Semiconductor devices

a. IGBT - IRGBC20S

b. MOSFET - IRF 740

whose characteristics are to be studied.

A variable DC power supply, using LM 317 regulator to vary the load voltage from

2.5Volts to 35 volts approximately. One more variable DC power supply using LM 317

regulator to vary the Gate Voltage from 1.5 volts to 15 volts approximately. Switch

and

fuse is provided in series with both the power supplies. A potentiometer of 25 watts

is

provided to vary the load current. A potentiometer of 3 watts is provided to vary the


Gate current.

Front Panel Details:

Mains Power ON/OFF switch to the unit with built-in indicator

For MOSFET:

Trans conductance Drain

V1= VDS1 = 10 V V1 = VDS2 = 15 V V2 = VGS = 3.5 V V2 = VGS = 3.8 V

VGS Volts ID mA VGS Volts ID mA VDS Volts ID mA VDS Volts ID mA

Trans

condu

ctanc

e

Chara

cteri

stics

Drain

Chara

cteri

stics

Obsev

ation

Table

:


s.no. VDS VGS

25V 3.6 V

15V 3.55 V

3.5 V

Procedure:

1. Make the connections as shown in the circuit diagram with meters.

Trans Conductance Characteristics:

2. Initially keep V1 and V2 zero. Set V1= VDS1= say 10V.

3. Slowly vary V2 (VGS) and note down ID and VGS readings for every 0.5V. and

enter in the tabular column. The minimum gate voltage VGS which is required

for

conduction to start in the MOSFETis called Threshold Voltage VGS (Th). If VGS

is

less than VGS (Th) only very small leakage current flows from Drain to

Source. If

VGS is greater than VGS (Th), the Drain current depends on magnitude of the

Gate Voltage. VGS varies from 2 to 5Volts.

4. Repeat the same for different values of VDS and draw the graph of I D V/S VGS.

Initially set V2 to VGS1= 3.5 Volts.

Drain Characteristics :

2. Slowly vary V1 and note down ID and VDS. For a Particular value of VGS1 there

is

a pinch off voltage (Vp) between drain and source as shown in figure. If VDS

is

lower than Vp, the device works in the constant resistance region and ID is

directly proportional to VDS. If VDS is more than Vp, constant ID flows from

the

device and this operating region is called constant current region.

3. Repeat the above for different values of VGS and note down ID V/S VDS

4. Draw the graph of ID V/S VDS for different values of VGS.


Transfer Characteristics Collector Characteristics

Obsevation Table :

s.no. VCE VGE

VCE1 = 10 V 3.5 V

15 V 3.8 V

25V = 5.2 V

Procedure:

. Initially keep V1 and V2 zero. Set V1= VCE1= say 10V.Slowly vary V2 (VGE) and

note down IC and VGE readings for every 0.5V. and enter in the tabular

column.

The minimum gate voltage VGE which is required for conduction to start in the

IGBT is called Threshold Voltage VGE (Th). If VGE is less than VGE (Th) only

very

small leakage current flows from Collector to Emitter. If VGE is greater than

VGE

(Th), the Collector current depends on magnitude of the Gate Voltage. VGE

varies


from 5 to 6Volts.

Repeat the same for different values of Vc and draw the graph of Ic V/S VGE.

Initially set V2 to VGE1= 5 Volts.

Collector Characteristics:

2. Slowly vary V1 and note down IC and VGE. For a particular value of VGE1 there

is

a pinch off voltage (Vp) between Collector and Emitter as Shown in figure. If

VGE

is lower than Vp, the device works in the constant resistance region and IC

is

directly proportional to VGE. If VGE is more than Vp, constant IC flows from

the

device and this operating region is called constant current region.

3. Repeat the above for different values of VGE and note down IC V/S VGE.

Draw the graph of I C V/S VGE for different values of VGE.

Result : Input and output characteristics of MOSFET and IGBT are determined.


EXPERIMENT 4:

STUDY OF UJT FIRING CIRCUIT

Aim: To turn-on SCR circuit using synchronized UJT relaxation oscillator.

Apparatus Required:

Serial

no.

Apparatus required no.s Quantity range

1 Connecting probes 1

2 Resistor 1 45 ohm

3 CRO 1

4 Multimeter 1

Details

of UJT

Firing

Module

This unit

consists

of the

following

component

s to

study

firing of

SCR using

UJT

relaxatio

n

oscillato

r. This

can also

be used

to study

UJT relaxation oscillator in

unsynchronized mode.

a) A step down transformer – 20V / 1A.

b) UJT relaxation oscillator circuit.

c) Pulse transformer isolation for SCR triggering.

d) SCR.

Procedure:


Firing of SCR using UJT:

1. Switch ON the mains supply, observe and note down the wave forms at the

different points in the circuit and also the trigger outputs – T1 & T11.

2. Now make the connections as given the circuit diagram using AC source, UJT

relaxation Oscillator, SCR and a suitable load.

3. Now switch ON the mains supply, observe and note down the output waveforms

across load and SCR. Draw the wave forms at different firing angle – 120, 90

&

60.

In the UJT firing Circuit the firing angle can be varied from 150° – 30°

approximately.

We cannot vary exactly from 0° - 180° as we vary in single phase converter firing

circuit.

Result: The input and output waveforms are observed.


EXPERIMENT 5:

SCR DIGITAL TRIGGERING CIRCUIT FOR A SINGLE

PHASE CONTROLLED RECTIFIER

Aim: To turn-on single phase controlled rectifier using SCR digital triggering

circuit.

Apparatus Required:

Sl. No Apparatus no.

Quantity Range

1. Digital Firing Circuit 1

-

2. Single phase half & fully controlled power circuit 1

-

3. CRO

1 -

4. Multimeter

1 -

5. Connecting probes

Circuit

Diagram:

Single

Phase

Full –

Controll

ed

Bridge

Converte

r:


Proced

ure:

1.

Switch

ON the

Mains

Supply

to the

Firing

circui

t.

Observ

e all

the

test

points

by

varying the firing angle and trigger outputs ON/OFF key. Observe the trigger

outputs and phase sequence. Make sure that all the trigger outputs are proper

before connecting to the power circuit. The trigger output pulse width varies

as

we vary the firing angle.

2. Make the connections in the power circuit.

3. Connect 30V tapping of the transformer secondary to the power circuit.

4. Connect the R-load between load points.

5. Connect firing pulses from the firing circuit to the respective SCR’s in the

power

circuit. Switch ON the MCB, switch ON the trigger outputs and note down

output

voltage, output current and the voltage wave forms across load and devices.

6. Draw the waveforms across load and device for different firing angle.

7. Repeat the same for different input voltage up to maximum voltage as provided

in the isolation transformer.

8. Repeat the same for R-L load with and without freewheeling diode and note

down the waveform.

Parameters and Observations :

1. Input voltage wave form.

2. Output voltage wave form (across the load)

3. Output current wave form (through the shunt)

4. Voltage wave form across thyristors (make this measurement only if isolations

is


used)

5. Study of variation of voltage and current wave forms with the variation of

firing

angle.

6. Study of effect of freewheeling diode in case of inductive loads.

Result: All waveforms are verified.

EXPERIMENT 6:

SINGLE PHASE FULL WAVE RECTIFIER WITH R AND R-L

LOADS

Aim: To turn-on single phase full wave rectifier using Single Phase Converter Firing

Unit or Microcontroller Firing Unit.

Apparatus Required:

Sl. No Apparatus

no. Quantity Range

1. Single Phase Converter Firing Unit or μC Firing Unit

2. Single phase half & fully controlled power circuit module 1

-

3. CRO

1 -

4. Multimeter

1 -

23.Connecting probes

- -

24.

Circuit Diagram:

Tabular column:


Sl No. Input Voltage-

Vin

Firing

angle

Output voltage

Procedure:

1. Switch ON the Mains Supply to the Firing circuit. Observe all the test points

by

varying the firing angle and trigger outputs ON/OFF key. Observe the trigger

outputs and phase sequence. Make sure that all the trigger outputs are proper

before connecting to the power circuit. The trigger output pulse width varies

as

we vary the firing angle.

2. Make the connections in the power circuit.

3. Connect 30V tapping of the transformer secondary to the power circuit.

4. Connect the R-load between load points.

5. Connect firing pulses from the firing circuit to the respective SCR’s in the

power

circuit. Switch ON the MCB, switch ON the trigger outputs and note down

output

voltage, output current and the voltage wave forms across load and devices.

6. Draw the waveforms across load and device for different firing angle.

7. Repeat the same for different input voltage up to maximum voltage as provided

in the isolation transformer.

8. Repeat the same for R-L load with and without freewheeling diode and note

down the waveform.

Parameters and Observations:

1. Input voltage wave form.

2. Output voltage wave form (across the load)

3. Output current wave form (through the shunt)

4. Voltage wave form across thyristors (make this measurement only if isolations

is

used)

5. Study of variation of voltage and current wave forms with the variation of

firing

angle.


6. Study of effect of freewheeling diode in case of inductive loads.

Result: Waveforms of single phase full wave rectifier were observed.

EXPERIMENT 7:

LAMP DIMMER CIRCUIT USING TRAIC – DIAC

Aim: To control the AC voltage using Triac – Diac combination

Apparatus Required:

Sl. No Apparatus Quantity Range

1. Lamp Dimmer Module 1 -

2. Lamp 1 60w

3. CRO 1 -

4. Multimeter 1 -

5. Connecting probes -


Details of the Module:

This unit consists of 50V AC supply, R-C phase shifting components, a diac, a Triac

and a

lamp to construct lamp dimmer circuit using Triac – Diac by controlling AC supply.

The

circuit works on the phase control method. It consists of phase shifting network

comprising of R and C. The firing of Triac is determined by the relative phase

difference

between line and gate control voltage. Adjusting the value of R changes the phase

difference between line and gate control voltage and this changes the firing instant

of

TRIA

C

and

the

load

volt

age.

Diac

is

used

to

trig

ger

the

TRIA

C.

Lamp

Dimm

er

Circuit Using Triac- Diac:

Procedure:

1. Make the connections as given in the circuit diagram.

2. Switch ON the mains supply, vary the firing angle potentiometer and observe the

variation in lamp brightness and also note down the voltage variation across

the

lamp.

Result: AC voltage using Triac – Diac combination was controlled.


EXPERIMENT 8:

DC-MOTOR SPEED CONTROL UNIT USING POWER

MOSFET / IGBT CHOPPER

Aim: To control the speed and direction of stepper motor.

Apparatus Required:



1. DC motor module 1 -

2. DC motor 1 -

3. Multimeter 1 -

4. Tachometer 1 -

Details of the Module

This trainer kit consists of two parts.(a) Power circuit and (b) Control circuit to

study

speed control of DC motor.

a) Power circuit :- The power circuits mainly consists of Power MOSFET, IGBT, a

freewheeling diode, and built in DC source for the chopper circuit and

Digital

meters to measure DC voltage and current.

A POWER MOSFET (IRF-460), an IGBT (IRGPH20KD) and a free wheeling diode are

mounted on a suitable heat sink and protected by snubber circuit and fuses. All the

device terminals are brought out on the front panel.

A built in DC source is provided in the unit for input to the chopper circuit. AC

mains

supply of 230 Volts is step down using a transformer with tappings and different AC

output voltage is selected using a rotary switch. The selected AC voltage is fed to a

diode

bridge rectifier to get rectified DC voltage and filtered using filter capacitor. A

glass fuse

is provided in series with the DC supply for protection. Different DC voltages of

24V,

48V, 110V and 220Volts can be selected using the rotary switch. Different DC voltages

are required to run DC motors of different ratings like 24V, 48V, 110V and 220 Volts.

One more diode bridge rectifier is provided to get 220 V ±10% DC voltages from

230

Volts AC mains for field supply of DC shunt motor. The field supply is not required

for

speed control of permanent magnet DC motor. A digital voltmeter and Ammeter are

provided to measure DC voltage and current.

Front Panel Details for MOSFET:

1. Vdc Digital Voltmeter to measure DC voltage.

Sl. No Terminals Description

2. Adc Digital Ammeter to measure DC current.

Insulated Gate Bipolar Transistot-IRGPH20KD

IGBT

International Rectifier make

3.

Collector, Gate & Emitter IGBT terminals.


MOSFET IRF 460 (International Rectifier make)

4.

Drain, Source & Gate MOSFET terminals.

Dfw Free wheeling diode - SPR 12PB.

5.

Cathode, Anode Free wheeling diode terminals.

Field Field supply 220 V ± 10% @ 2Amps for field of

DC

6.

220V DC shunt motor with neon lamp indicator.

Volt-Select Rotary switch to select DC supply as follows.

OFF DC supply is OFF.

1 24 V DC.

7.

2 48VDC.

3 110VDC.

4 220V DC

Step down transformer with tappings @ 20V, 40V,

8. Transformer 80V and 170Volts to get different DC output

Voltages.

Diode bridge rectifier -10Amps/600V to rectify

9. Rectifier

input AC supply to DC supply.

11.C Capacitor filter.

12.

TABULAR COLUMN (Motor control):

Sl.

No.

Duty cycle Vout Io Speed

Note: Since the DC supply is unregulated DC supply, the input will slightly drop as

the

Draw the graph of Duty Cycle V/S Vo.

current increases.


Control Circuit :

The control circuit is 89C51 microcontroller based to accurately generate the

control output. The duty cycle can be varied from 0-100%, Frequency of the

•

chopper can varied from 50Hz to 500Hz.

2 line x 16 character LCD display to indicate the parameters and their

values.

4 keys to increment & decrement the chopper frequency or Duty cycle and to

•

Run/Stop the output with soft start and stop feature.

•

Opto coupler based driver circuit to drive MOSFET/IGBT.

•

Procedure:

1) Keep the volt – select switch at OFF position and switch on the mains supply to

the

unit.

2) The LCD display shows –

POWER MOSFET/IGBT CHOPPER

0FF DCY – 0 FRQ 50

Digital volt meter and ammeter shows 000 – 000

3) Measure the Field voltage using digital voltmeter. It should be 220V ± 10%

approximately and the neon lamp glows.

4) Now keep the voltage select switch at position 1 and measure the voltage at VDC

terminals. It should be 24 volts. The output voltage should be 48V when VOLT-

SELECT switch at position – 2, 110V when the VOLT-SELECT switch at position –

3, 220V when the VOLT-SELECT switch position at 4 approximately.

5) Make sure that the DC supply is correct. Now observe the driver output using a

CRO by varying duty cycle and frequency.

6) Make sure that the driver output is proper before connecting to the gate/emitter

or gate/source of IGBT or MOSFET.

7) Now all the outputs are proper. Make the connections as given in the circuit

diagram.

8) Initially select 24 volts DC. Connect a Rheostat – 100Ω/2 Amps.

9) Apply the driver output pulses.

10)Vary the duty cycle and observe the load voltage and tabulate the Voltmeter and

Ammeter readings.

11)Now change the frequency to some other value and change the duty cycle and

note down the readings.

12)Repeat the same procedure for 48 volts, 110 volts and 220 volts.


13)In case of DC shunt motor experiment, connect field supply to the field

terminals

before connecting to the armature supply. And the field supply should be

removed

only after switch OFF the armature supply.

14)Use higher value of Rheostat – 470Ω /1Amp to work at 110 volts / 220 volts DC

supply.

15)External DC supply can also be used as input to the chopper to get regulated DC

Supply.

Result: The Speed increase and Speed decrease of DC motor was studied.

EXPERIMENT 8:

STEPPER MOTOR CONTROLLER

Aim: To control the speed and direction of stepper motor.

Apparatus Required:


1. Stepper motor module 1 -

2. Connecting probes -

3. Stepper motor 1 -

Details of the Module

This unit is microcontroller based, controller circuit to accurately generate pulses

to energize

the stepper motor winding in the desired sequence. Power transistor based driver

circuit to

drive the Stepper motor. From this controller we can set the speed of the stepper

motor in RPM,

set the number of steps the motor can move. We can set the direction of rotation –

forward and

reverse direction. We can also set Half step and full step mode.


Front panel details:

1. Mains Power ON/OFF switch on the unit with built-in indicator

Sl. No Terminals Description

2. Display LCD display to display the parameter & values.

Key Board

SET To set the Parameter.

3. INC To increment the set parameter values.

DEC To decrement the set parameter values.

RUN/STOP To start and stop the stepper motor.

4. +V 5V @ 2Amps DC supply for stepper Motor (Built in)

5. +5V 5V for control circuit (Built in)

6. GND Supply ground point.

7. FUSE 2 Amps fast blow glass fuse for short circuit protection.

A1, A2, B1,

8. Output points to connect to the A1, A2, B1, & B2 leads of

stepper motor.

B2

9. LED’s To indicate the status of output.

Back Panel Details

2 pin Mains cable and Fuse holder with 500mA Glass fuse.

Circuit Diagram:

SWITCHING LOGIC SEQUENCE:

Full step

A1 A2 B1 B2

0 1 0 1

Red Black Blue Green

0 1 1 0

1 0 1 0

1 0 0 1

Q1 Q2 Q3 Q4

Half step

A1 A2 B1 B2

0 1 0 1

Red Black Blue Green

0 0 0 1

1 0 0 1

1 0 0 0

1 0 1 0

0 0 1 0

0 1 1 0

0 1 0 0

Q1 Q2 Q3 Q4


To change the direction read sequence from bottom to top.

1. Connect A1, A2, B1 and B2 leads of stepper motor to the corresponding output

Procedure:

terminal points. And two common terminals to +V supply.

2. Switch ON the mains supply to the unit. Check the Power supplies.

The unit displays STEPPER MOTOR

After few seconds it displays STOP S/R R/F H/F

RPM 1 FOR FULL

Stop - Corresponds to RUN/ STOP selection.

S / R - Corresponds to Step / RPM (Continuous rotation) selection.

R / F - Corresponds to Reverse / Forward - direction selection.

H / F - Corresponds to Half step / Full step selection.

Now RPM blinks. Press INC / DEC key to select STEP or RPM (Continuous

rotation) mode.

After selecting RPM / STEP mode press SET key to select the mode. Now 1

3.

blinks. This corresponds to number of rotation or number of steps selected.

4. Press INC / DEC key to select the speed or steps. Press SET key to set the

rpm /

number of steps. Now FOR blinks. This corresponds to direction of rotation -

Forward.

5. Press INC / DEC key to select the direction of rotation and press SET key to

select. Now FULL blinks. This is corresponds to Full step. Press INC / DEC

key to

select Half step / Full step mode and press SET key to select Half / Full

step

mode.

6. Now the setting is over. Press RUN / STOP key, the stepper motor rotates at

the

set speed if RPM is selected or it moves the number of steps set and stops.

Again

pressing RUN/ STOP key the motor stops if it is in RPM mode or it again moves

the number of set steps and stops.

7. Set the step mode, 1 step, FORWARD and Half step mode. Check the output

status

by LED indication for each step and verify with the switching logic sequence

as

given in the below truth table.

8. Repeat the same for Full step mode. Repeat the same for Reverse direction.

Result: Speed control and direction of stepper motor was observed and studied.

EXPERIMENT 10:


STUDY OF UNIVERSAL MOTOR & INDUCTION MOTOR

SPEED CONTROL UNIT - 0.5 HP/220V AC/DC

Aim: To control the speed of a universal motor ad a single-phase induction motor

using

A. C. voltage controller.

Module Details:

This unit consist of two parts:

(a) Firing Circuit and

(b) Power Circuit.

This unit, generates line synchronized 2 pulse transformer isolated trigger

pulses.

(a) Firing Circuit :

These trigger pulses can be used to trigger :

Single phase AC phase control using SCR’s (Anti-parallel SCR’s)

Single phase AC phase control using Triac.

Single phase Half wave rectifier (Single SCR)

i)

Single phase Full wave rectifier (Two SCR’s)

ii)

Single phase Half controlled bridge rectifier (Two SCR’s & Two diodes)

power

iii)

circuits.

iv)

v)

The firing circuit is based on zero crossing detector, ramp generator, op-amp

comparator and amplifier/pulse transformer isolation method.

THEORY:

1. Speed control of universal motor using ac voltage control:


a. Using SCR

b. Using Triac

S

p

e

e

d

c

o

n

t

r

o

l

o

f

D

C

m

o

tor using DC – control

Single phase Full controlled bridge rectifier

OBSERV

ATION

DETAIL

:

Sl. No. Input Output Firing angle Output Speed


Voltage Voltage Current

(b) Power Circuit:

The power circuit consists of 2 SCR’s, 3 diodes and a Triac. The power devices are

mounted on suitable heat sink for power dissipation. The snubber circuit is connected

for dv/dt protection. A fuse is also provided in series with the devices for short

circuit

or over current protection. In the input side a MCB is provided to switch ON/OFF the

supply to the power circuit.

A digital voltmeter and an Ammeter is provided to measure the Input / Output voltage

and current with ac / dc selector switch.

Procedure:

1. Make the inter connections in the power circuit as given is the circuit

diagram.

2. Switch ON the firing circuit and observe the trigger outputs. Make sure that

the

firing pulses are proper before connecting to the power circuit.

3. Then connect the trigger output from firing circuit to corresponding SCR’s /

Triac.

4. In the power circuit initially set the AC input to 30 volts. Switch ON the

MCB.

Switch ON the Trigger outputs switch. Select the SCR / Triac selection

switch and

observe the output wave forms across ‘R’ load by varying the firing angle

potentiometer.

5. If the output wave form is proper then you can connect the motor & increase

the

input voltage to rated value 0 – 230V gradually.

6. Vary the firing angle and note down O/P voltage and speed of the motor.

NOTE: If you are not getting the O/P after all proper connections interchange AC O/P

terminals, by turning OFF the MCB. This is just to synchronize the power circuit with

firing circuit.


Result: Speed control of universal motor and single phase induction motor was

studied.

EXPERIMENT 10:

STUDY OF SINGLE PHASE PWM INVERTER – IGBT

BASED

Aim: To study the behavior of MOSFET or IGBT based single-phase full-bridge inverter

connected to R load.

Apparatus Required:

1. PWM module 1 -


2. CRO 1 -

3. Multimeter 1 -

4. Connecting probes

Details:

This unit consist of two parts :

(a) Control Circuit and

(b) Power Circuit.

a) Control Circuit :

This is based on 89C52 Microcontroller. 2 X 16 line LCD display to indicate and

monitor

the Parameters and type of modulation. The following modulation techniques are

incorporated:

a) Single pulse modulation

b) Sine triangle modulation

c) Multi pulse modulation

d) Trapezoidal modulation

e) Stair case modulation

5 keys: SET, INC, DEC, FRQ/DTY and RUN/STOP to vary and set the parameters.

Optocoupler based isolation circuit to drive 4 IGBTs connected as 1-ph. Bridge

Inverter.

b) Power Circuit:

This unit consists of 4 IGBT’s unit built in diodes of rating 19A/600V. All the

devices are

mounted on proper heat-sink and protected by snubber circuit and fuse. All the

terminals are brought out on the front panel. In the input side a switch and a fuse

are

provided for DC input 24V @ 2A. The frequency can be varied from 20Hz to 100Hz. The


duty can be varied from 0% to 100%. Carrier frequency – 9 pulses per each half cycle.

Result: The behavior of MOSFET or IGBT based single phase full bridge inverter was

studied.


LAB MANUAL

Version No. POWER SYSTEM -1

Subject POWER SYSTEM -1

Subject Code

EX-505

Scheme New

Class/Branch

V SEM

Author



BIT, BHOPAL

LAB MANUAL

Power System-I

List Of Experiment

1. Study Of Power Flow Diagram.

2 Study of Transmission line design.

3 Study of Advanced Transmission Technologies.

4 To study the Tower and Support for Over Head Transmission

line.

5 Study of line insulator used in transmission line.

6 To study the Electrical Design of Overhead Lines.


EXPERIMENT NO: 1

OBJECT:

Study Of Power Flow Diagram.

Customer service Drop

120/240 volt

Primary distribution

4KV - 46KV

Step down

Transformer


EXPERIMENT NO: 2

OBJECTIVE:

Study of Transmission line design.

The electric lines that generate the most public interest are high-voltage

transmission lines. These

are the largest and most visible electric lines. Most large cities require several

transmission lines for

reliable electric service. Figure 2 shows two 345-kV double-circuited transmission

structures sharing

the same right-of-way (ROW). Double-circuited means that the transmission structure

is carrying

two sets of transmission lines, each with three conductors.

Transmission lines are larger than the more common distribution lines that exist

along rural roads

and city streets. Transmission line poles or structures are between 60 and 140 feet

tall. Distribution

line structures are approximately 40 feet tall.

There are several different kinds of transmission structures. Transmission structures

can be

constructed of metal or wood. They can be single-poled or double poled. They can be

single-

circuited carrying one set of transmission lines or double-circuited with two sets of

lines. Figure 3

shows a close up of a commonly built double-circuited, single-pole transmission

structure. Figure 4

shows diagrams of different types of transmission structures.

Diff

eren

t

tran

smis

sion

stru

ctur


es have different material and construction costs, and require

different right-of-way widths, distances between structures (span length), and pole

height. These

issues also vary with different voltages. In the past, many transmission lines were

constructed on H-

frame wood structures and metal lattice structures. New lines are most often

constructed with single

pole structures because of right-of-way width limitations and environmental

considerations. Current

right-of-way widths vary between 80 to 140 feet. A typical right-of-way is diagrammed

in Figure 5.

EXPERIMENT NO: 3

OBJECTIVE:

Study of Advanced Transmission Technologies.

Not all new power transmission technologies are currently ready for commercial use.

Many are still

in the experimental and prototype stage. The new technologies mostly fall into two

categories – new

materials that may increase the amount of power that can be safely transferred

through right-of-

ways, and devices that more finely control the flow of power. New power control

devises improve

the capacity of existing lines. New material advances include high-temperature super-

conducting

technology and advanced composite conductors. New technologies that better manage the

flow of

power include high-voltage direct current systems, superconducting magnetic energy

storage, flexible

alternating current transmission system devices, and real-time ratings on

transmission lines. The

disadvantage of many of these new technologies is that they are still being

researched and their cost

is extremely high.


High-Temperature Superconducting (HTSC) technology

The conductors in HTSC devices operate at extremely low resistances. However, they

require

refrigeration (generally liquid nitrogen) to super-cool the conductors, increasing

maintenance costs

and the complexity of the system. The benefits are cables that can carry five times

as much power

as traditional copper wires with the same dimensions. This greatly reduces the number

of new

transmission lines and the amount of new right-of-way required.

Composite conductors

Usually transmission lines contain steel-core cables that support strands of aluminum

wires which

are the primary conductors of electricity. New cores developed from composite

materials reduce

sagging with high temperatures associated with more power going through transmission

lines. Life-

cycle costs of the experimental conductors are high. The installation and maintenance

procedures

continue to be developed.

Superconducting Magnetic Energy Storage (SMES)

SMES devices would be strategically located in a transmission grid to damp out

disturbances. SMES

systems use a cryogenic technology to store energy by circulating current in a super-

conducting coil,

advanced line-monitoring equipment to detect voltage deviations, and inverters that

can rapidly

inject the appropriate combination of real and reactive power to counteract voltage

problems. By

correcting for potential stability problems, these systems permit the operation of

transmission lines

at capacities much closer to their thermal limits than currently possible. However,

the expense of

these cooling systems is a disadvantage. American Transmission Company currently has

six SMES

devices in use on its system to address low-voltage and grid instability issues.

Flexible AC Transmission System (FACTS) devices

Currently, the transmission grid relies mostly on slow, electromechanical switches

and human

operators. Mechanical switching creates split-second delays in responding to

problems. A variety of


power-electronic power switching and other devices are being developed that will

operate much

faster, along with sensors capable of spotting disturbances instantly. These systems

will improve

control and stability of the transmission grid and permit transmission lines to

operate closer to their

thermal limits, making better use of existing wires. However, these FACTS devices are

very

expensive, costing several hundred million dollars for the conversion of a single

line.

Real-time ratings of transmission lines

This is another use of advanced information technologies to expand the capacity of

existing

transmission systems. Special devices can measure the real time tension in

transmission lines,

ambient temperature and wind speed, or cable sag. The results of the measurements are

telemetered

to the control center, which then adjusts the line rating accordingly. Once again the

drawback with

this technology is the high cost relative to the incremental potential increase in

capacity.


EXPERIMENT NO: 4

OBJECTIVE:

To study the Tower and Support for Over Head Transmission line.

Theory:

The support for an overhead line must be capable of carrying the load due to the

conductors and insulators together with the wind load on the support itself.

Types of line support-

(a) Wooden poles

(b) RCC poles

(c ) Steel tubular poles

(d)Steel towers.

(a) Wooden poles :

poles made of chemically treated treated wood are used for distribution lines .

specially in ares where ample supplies of good quality of wood are available. They

are very economical but susceptible to decay. To reduce decay Wooden poles are

protected by an aluminum or zinc cap at the top and bitumen coating over the portion

of the pole in the ground. One pole used for low voltage line and two poles are used

for 33 kv lines two poles in A or H formation are uesd.

(b) RCC poles :

Poles made of reinforced cement concrete are stronger but more costly then wooden

poles. They have very long life and need little maintenance. However , They are bulky

and heavy . They are widely used for distribution lines up to 33 kv in urban area.

Prestressed concrete poles are less bulky and lighter then RCC poles.


(c ) Steel tubular poles :

These may be stepped or swaged type . A stepped pole is manufactured from a single

tube, the diameter being reduce in parallel step by passing the tube through a series

of dies . A swaged pole is made of different diameter which are swaged together when

hot They posses the distinct advantages of light weight high strength to weight ratio

and long life .the use of cap at the top of the concrete muff in the ground and

regular painting prolongs their life. They are very widely used for lines up to 33

kv.

Two Angle Structures and a Transmission Line Crossing a Road

(d)Steel Towers :

Lines of 66 kv and above are invariably supported on steel towers. They are

fabricated for painted or galvanized angle which can be transported separately and

the erection done on site . Steel tower have the advantage of a very long life and

high degree of reliability. They can stand very severe weather conditions.

They can very suitable for double ckt lines. Tower many shape and sizes are used for

different types of lines.

The common configurations are

narrow base single ckt up to 33 KV

Broad base single ckt up to 66 KV

Double ckt 132 KV

Cats head single ckt for 220 KV

Single ckt with two sub-conductors per phase for 400 KV .


EXPERIMENT NO: 5

OBJECTIVE :

Study of line insulator used in transmission line.

Theory:

The insulator used for transmission lines are classified as

Pin Insulators

Suspension type

Post type

Strain insulators


Pin type insulator :

A pin type insulator is small, simple in construction and cheap. It is used on lines

up to and including 33 KV lines. The conductor is bound into a groove on the top of

the insulator which is cemented on to a galvanized steel pin attached to the crossarm

on the pole or the tower .To avoid the direct contact between porcelain and the metal

pin , a soft metal thimble is uesd . line conductor and An adequate length of leakage

path is obtain by providing the insulator with two or three petticoats or rain sheds.

These are so designed that even when the outer surface of the insulator is wet due to

rain sufficient leakage resistance is still given by the inner dry surface.

In its electrical behavior the pin insulators may be compared to a complicated series

of condenser

with series resistance and shunt resistance.

Pin type insulator are used only upto about 33 KV because for higher voltage they

tend to be very heavy and more costly than suspension type insulators.

Suspension type Insulators:

The cost of a Pin Insulators are rapidly with increase in line voltage. Therefore,

suspension insulators are used for line above 33 KV. They are also known as Disc type

insulators or string insulator

A suspension Insulator consists of porcelain disc units mounted one above the other.

Each disc consists of a single shed of porcelain grooved on the under surface to

increase the creepage distance . The upper surface of each disc is inclined at the

suitable angle to the horizontal in order to ensure free drainage of water. Each disc

is provided with a metal cap at the top and a metal pin underneath. The cap is

recessed so as to take the pin of another unit and thus a string of any required

number of units can built up.

Post Insulators:

These are used for supporting the bus bars, and disconnecting switches in supporting

bus bars, and disconnecting switches in substation . A post insulator is similar to a

pin type insulators but has a metal base and the frequently a metal cap so that more

than one unit can be mounted in series.

In extra high voltage sub station 400 kv above polycon post insulator are used. Also

known as multi cone insulator . These insulator is puncture proof, solid core

insulator for outdoor use. In these insulator the porcelain elements are in the form

of cones smugly fitting one one inside the other and boded by special cement . The

path is through many layers of porcelain cones and the voltage required to puncture

this path is many times the external flash over voltage so that the insulator is

almost puncture proof.

Strain insulator:

these are special mechanically strong suspension insulators and are used to take the

tension of the conductor at the line termination and at position where there is a


change in the direction of line .

The discs of a strain insulator are in a vertical plane as compared to the discs of

suspension insulator which are in a horizontal plane. One extra long span like river

crossing Two or three strings of strain insulator .arranged in parallel, are often

used.


EXPERIMENT NO: 6

OBJECTIVE:

To study the Electrical Design of Overhead Lines.

Theory:

The Design of transmission line involves a number of technical and economic aspects.

The capacity and distance of transmission are specified the voltage regulation and

efficiency are also specified. The design detail include line voltage, size of phase

conductor, span , specing and configuration of conductor , number and size of earth

wire .

Selection of Conductor :

Types of conductors used in overhead transmission lines.

Hard drawn Copper

Hard drawn Aluminium

Steel cored Aluminium Conductors

Cadmium Copper Conductors

Steel Cored Copper Conductors

Copper weld conductors

All Aluminium Conductors

Aluminium Conductor Steel Reinforced

Expanded ACSR Conductors

All Aluminium Alloy Conductors

ACAR Conductors

Alumoweld Conductors


Phospher Bronze Conductors

Galvanized Steel conductors

1 Hard drawn Copper:

Copper for overhead lines is hard drawn to give a high tensile strength. It has a

high electrical conductivity , long life, and high scrap value. Other property of

hard drawn copper conductivity are given table along with the properties of hard

drawn Aluminium . Copper conductor is most suitable for distribution work where spans

are short and tapping are more.

Electrical and Mechanical charactersics of Hard drawn Aluminium and Copper wires.

Cadmium Copper Conductors:

The tensile strength of copper is increased by approximately 50 percent by adding

about 0.7 to 1/0 percent cadmium to it . The conductivity is , However, reduced by

about15 to 17 percent. The property of higher tensile strength enable it to be

erected on longer spans with the same sag. Like hard drawn copper this alloy posses

the advantage of easy jointing. The small diameter render these conductor unsuitable

to be used on high voltage lines where corona losses are serious.

Steel Cored Copper Conductor:

One or more layers of copper strands a steel core to make a steel cored copper


conductor . The steel core added to tensile strength of the conductors. The core is

provided with bituminised cotton tape in order to protect the conductors from the

galvanic action .

Copperweld Conductor:

Copper is welded on to a steel wire by hot rolling and cold drawing a billet of steel

coated with copper. It is ensured that the uniform thickness of copper is welded .the

conductivity of copperweld conductors varies from 30 to 60 percent of that of a solid

copper conductor with the same diameter .the conductivity of the standard grade is

about 40 percent . The modulus of elasticity is about 16800kgf/mm2 . And coefficient

of linear expansion is 1.296x10-5oC . Copperweld conductors may be used for longer

spans such as river crossing.

All Aluminum Conductors:

The increasing trends in the cost of copper has resulted in replacement of copper and

adoption of aluminum for transmission work. At least 99.5 percent electrolytically

refined aluminum is rolled and hard drawn for conductor use. For a given resistance

the cross-section of the aluminum conductor is 60 percent greter then that of copper

and its weight is only 48.3% of that of copper conductor .

ACC are used for distribution lines in urban ares and short transmission lines with

the lower voltage.

Where high winds are frequent, aluminum conductors due to their lightness, large

diameter and greter sag, are more likely to swing resulting in inter phase faults.

Aluminum Conductors Steel Reinforced (ACSR):

Conductors made of all aluminum are not sufficiently strong mechanicaly for

construction of long span lines. The deficiency in strength can be compensated by

adding a steel core to the conductor.such a conductor is called Steel cored aluminum

SCA or ACSR.

It has 7 steel strands forming a central core around which there are two layer of

24 aluminumstrands. The conductor stranding is specified as 24A1/7 St.

The important advantages of ACSR is it high tensile strength and light weight. The

sag is therefore small and the line can be design with shorter supports or longer

spans for a given sag.

The presence of steel in ACSR conductor create a difficulty in making splices and

dead ends. In urban construction this is particularly important..

In industrial and coastal areas this galvanic corrosion may be serious to effect the

life of conductor , but this is now avoided due to CORONA.

Expanded ACSR:

sometimes a plastic or fibrous material is introduced between the steel core and

aluminum strands to make the diameter of the conductor large to reduce corona loss

and radio interferencesss



LAB MANUAL

Version No. CONTROL SYSTEM

Subject CONTROL SYSTEM

Subject Code

EX-602

Scheme New

Class/Branch

VI SEM

Author Gaurav Shrivastav




Control System LAB.


1 Study of ON- OFF controller.

2 Study of Prportional controller.

3 Study of Integral controller.

4 Study of Derivative controller.

5 Study of P-I controller( Prportional + Integral controller)

6 Study of P-D controller ( Prportional+ Derivative controller)

7 Study of PID( Prportional + Integral +Derivative )controller.

8 Study of PID in close loop system.

9 Study of Open Loop system.

10 Study of Close Loop system.

11 Study of Close loop with disturbance.

12 To study and observe Voltage to frequency converter

13 To study and observe Frequency to Voltage converter

14 To study and implement Light intensity control using PWM method

15 To study and observe Characteristics of Photoconductive Cell

(LDR)

16 To study and implement Characteristics of DC Motor (Speed / Vin).

17 To study and implement Bidirectional motor speed control


18 To study and implement Tachogenerator.

19 To study and implement Motor control using PWM method

20 To study and observe Position control of DC Servo Motor

21 To study and implement DC Motor Control-Open Loop

22 To study and observe DC Motor Control-Close Loop

23 To study and implement Temperature Control-Open Loop

24 To study and observe Temperature Control-Close Loop

25 To study and implement Light intensity control-Open Loop

26 To study and observe Light intensity control-Close Loop

27 Calibration of RTD Characterstics

28 Study of RTD characteristics

29 Study open loop response of the process

30 Study of ‘On/Off’ controller

31 Study of Ziegler- Nichols PID controller tuning

32 Study of P-control action using the software

34 Study of PI-control action using the software

35 Study of PID-control action using the software

36 Study of the Industrial PID controller as ‘On/Off’

Controller

37 Study of the Industrial PID controller as P Controller

38 Study of the Industrial PID controller as PI Controller

Study of the Industrial PID controller as PID Controller


Experiment:1

Object:

Study of ON- OFF controller.

Apparatus Required:

(1)PID Kit

(2)Multimeter

(3)connecting wire probes

Procedure:

Connet the ckt as shown in fig.

On the power supply .

Set 1 volt at TP 1 and apply it to SetPoint of On/Off controller.

From disturbance block , apply to variable input of On/ Off controller and vary

the disturbance knob as required.

Now measure the voltage at variable input of On/Off controller by digital

multimeter


Conclu

sion :

When

knob

of

On/Off

contro

ller

at min

positi

on you

will

find

that

LED

will

glow

voltage of variable goes slightly above the set point ,But if knob of On/Off

controller at max position you will find that LED will glow voltage of variable

goes slightly above then the min set

voltage value .

So the differential gap in min position is less than the max position setting of On

/Off controller.

Experiment: 2

Object:

Study of Proportional controller.

Apparatus Required:

(1)PID Kit

(2)Multimeter


Procedure:

1 Make connection as shown in fig.

2 On the power supply .

3 Ground PV and input of summing Blocks that are not used.

4 Set .5 volt at TP 1.

5 Apply set point to proportional input.

6 Check the output of proportionsl block with digital voltmeter.


7 Vary slowly the value of Kp and find out the proportinal band.

8 we can check the effect on Kp on CRO. also

Obse

rvat

ion

:

S.no Input voltage Kp O/p voltage

1 .5 .2 0.819

2 .5 .3 0.920

3 .5 .4 1.54

4 .5 .5 1.86

5 .5 .6 2.58

Conclusion :

as we vary the value of Kp the Out put voltage vary in magnitute of voltage will

increase by varying Kp.

Experiment:3

Object:

Study of Integral controller.

Apparatus Required:

(1)PID Kit

(2)Multimeter


Procedure:




4 Apply square wave to the input of Integrator.

5 Check the out put of integrator block on CRO


6 Vary slowly the Ki and observe the changes in the output.

Conclu

sion :

By

changi

ng the

value

of Ki

we

observ on CRO that the slope of the wave will increase with increment in the value of

Ki.

Experiment: 4

Object:

Study of Derivative controller.

Apparatus Required:

(1)PID Kit

(2)Multimeter


Procedure :





4 Apply square wave to the input of Derivative .

5 Check the out put of Derivetive block on CRO.

6 Vary slowly the Kd and observe the changes in the output.

Conc

lusi

on :

By

chan

ging the value of Kd we observ on CRO that the tip of the of wave will increase with

increment in the value of Kd.

Experiment: 5

Object:

Study of P-I controller( Prportional + Integral controller)

Apparatus Required:

(1)PID Kit

(2)Multimeter


Procedure:




4 Apply square wave to the Set Point SP .

5 Check the output TP 10 of summing block on CRO that will look like as shown in

fig.


6 Vary slowly the value of Kp and Ki and observe the changes in waveshape.

Conclusion :

When we vary the value of Kp the

mag of square wave increase and by

vary the Ki the slop will add at

the top of the square wave shape .

Experiment: 6

Object:

Study of P-D controller ( Prportional+ Derivative controller)

Procedure:

1 Make Connection as shown in fig.

2 Switch On the power supply .




fig.

6 Vary slowly the value of Kp and Kd and observe the changes in waveshape.


Conclusion :

When we vary the value of Kp the mag of square wave increase and by vary the Kd , the

tip of the first edge is in slightly greater than the last edge and these

decrement is in the shape of exponentialy decrement shape at both side this effect

seen at upper side as well as lower side of wave shape.

Experiment: 7

Object:

Study of P-I-D controller ( Prportional+Integral+ Derivative) controller

Procedure:







fig.

6 Vary slowly the value of Kp ,Ki and Kd and observe the changes in waveshape.

Conclusion :

When we vary the value of Kp the mag of square wave increase and by vary the Kd , the

tip of the first edge equal of the last edge and Kd effect add the Right mark

shape between two edges .


Experiment: 8

Object:

Study of PID in close loop system.

Apparatus Required:

(1)PID Kit

(2)Multimeter


Procedure:






fig.

6 Vary slowly the value of Kp ,Ki and Kd and observe the changes in waveshape.


Experiment: 9

Object:

Study of Open Loop system.

Apparatus Required:

(1)PID Kit

(2)Multimeter


Procedure:




4 By controlling the knob of set point , we can set +/- 10 volt at TP 1 and find

the relation ship between input and output variable .

5 After finding the relationship between output and input voltage , measure the

overall gain gain proportional block Kp.

6 Now note the value of TP1 to which output at TP 10 repeat the measurement for 2

volt .

7 The chain amplification is defined as the ratio of the output difference to

input difference.

Observati

on :

s.no i/p voltage o/p voltage Diffrece in sequencial o/p

1 1 0.7 0.48

2 2 1.18 0.63


3 3 1.81 0.60

4 4 2.41 0.58

5 5 2.99

Conclusion :

the output variable can be manualy controlled by reading the instrument connected to

the output and varying the amplitude of input until the output variable reaches the

required value . With thiconcept open loop system is cleared.

Experiment: 10

Object:

Study of Close Loop system.

Apparatus Required:

(1)PID Kit

(2)Multimeter


Procedure:




4 set the feedback rate by adjusting the feedback knob.

5 To set the feed back rate first apply 2 volt at i/p of feedback and measure the

o/p of that block such that output is 1 volt so the feedback rate is 0.5 , repeat the

process for different outputs.

Obse

rvat

ion

:

s. no Input voltage Output voltage Feedback rate

1 2 1 0.5

2 2 0.5 0.25


3 2 0.4 0.20

4 2 0.25 0.12

5 2 0.20 0.12

Conclusion :

Experiment: 11

Object:

Study of Close Loop system with disturbance .

Apparatus Required:

(1)PID Kit

(2)Multimeter


Procedure:




4 Read out the output voltage once with connect feedback and once with out connect

the feedback.

5 these all value is in presence of disturbance.

Observation

:

s.no Out put voltage with

feedback

o/p voltage without feedback

1 0.4 1.08

2 0.808 2.07


3 1.24 3.62

4 1.56 4.18

5 2.01 5.39

Conclusion:

Experiment 12

Aim: To study and observe Voltage to frequency converter

Apparatus required :

1. NV3000-Control System Lab

2. Oscilloscope/ Frequency counter

3. Voltmeter

4. 2 mm patch cords (3)

Circuit diagram :

Proc

edur

e :

1.

Make

the

conn

ecti

ons

acco

rdin

g to

the Figure 23

2. Connect the NV3000-Control System Lab to AC mains.

3. Switch ON the trainer by Power switch.

4. Set the potentiometer in such a way that it gives 0.5V output at tp2 and measure

the frequency at tp3 using oscilloscope/ frequency counter.

5. Set the potentiometer in such a way that it gives 1.0V output at tp2 and measure

the frequency at tp3 using oscilloscope/ frequency counter.

6. Now repeat the step 4 and 5 for 1.5V, 2.0V up to 5.0Vand measure the frequency


at tp3 using oscilloscope/ frequency counter.

7. Switch OFF the power switch.

8. Now make a observation table and plot a graph between voltage (Vin) and

frequency (Fout).

Observation table :

s.no voltage (Vin) at tp2 Frequency(Fout) at tp3

1 0.5 55 Khz

2 1.0 60 Khz

3 1.5 64.30 Khz

4 2.0 68.45 Khz

5 2.5 72.10 Khz

6 3.0 79.1 Khz

Experiment 13

AIM: To study and observe Frequency to Voltage converter



2. Voltmeter

3. Oscilloscope/ Frequency

4. 2mm patch cords (2)

Circuit

diagram

:

Procedu

re :

1. Make

the

connect

ions

accordi

ng to

the

Figure 24



4. Set the clock frequency at 5 KHz and observe the voltage at socket 5 using Digital

Voltmeter.

5. Tune the potentiometer and increase the clock frequency for every 5 KHz (5 KHz,

10 KHz, 15 KHz ……….) and observe the change in voltage with respect to

frequency.



7. Now make an observation table and plot a graph between frequency (Fin) &

voltage (Vin).

Experi

ment

14

AIM:

To study and implement Light intensity control using PWM method




Circuit diagram :

Proc

edur

e :

1.

Make

the

conn

ecti

ons

acco

rdin

g to the Figure 25.

2. Connect the NV3000-Control System Lab to AC mains


4. Slowly tune the potentiometer and observe the change in intensity of the Lamp-1.


Conclusion :

You will observe that on varying the PWM driver input voltage the ON –OFF time of

pulse will vary and because of which intensity of lamp will change. The ON-OFF

effect of PWM driver output on lamp will not be observed because of fast switching


speed.

Experiment 15

AIM: To study and observe Characteristics of Photoconductive Cell (LDR)



2. Voltmeter


Circuit diagram :

Theory :

Electrical conduction in semiconductor materials occurs when free charge carriers


e.g.

electrons are available in the material when an electric field is applied. In certain

semiconductors. Photoconductive cell are elements whose conductivity is a function

of incident electromagnetic radiation. Since, resistance of these materials decrease

with increase in incident light, therefore these materials are also called Light

Dependent Resistor or LDR. Commercially available photoconductive cell materials

are cadmium sulfide (CdS) and cadmium selenoid (CdSe) with band gap of 2.42 eV &

1.74 eV respectively. On account of the large energy bands, both the materials have a

very high resistivity at ambient temperature which gives a very high value of

resistance for practical purposes. The photoconductive cells use a special type of

construction which minimizes resistance while providing maximum surface.

Photoconductive cells are made by chemically sintering the required powder into

tablets of the protective envelope of glass or plastic. Electrons are deposited on

the

tablet surface and are made of materials which give an ohmic contact but with low

resistance compared with that of the photoconductor.

The electrodes are usually in the form of interlocked fingers as shown.

Photoconduct

ive cell are

made from cadmium sulphide doped with silver antimony or

indium chemically deposited on a substrate. Light falling on the sensitive area

breaks

chemical bonds. The resulting electrons and holes become available to increase the

conductivity. These bonds are slow to re-form when light is removed and the response

time is sluggish. The resistance of the ORP12 drops dramatically as the incident

light

increases. Its characteristics are given in table given. The device requires a

suitable

load resistor to provide a voltage output which then falls with increasing

illumination.

The characteristics of a photoconductive cell vary considerably depending upon the

type of material used. When the cell is kept in darkness its resistance is called

Dark

Resistance. The dark resistance may be as high as 1010 Ω . If the cell is illuminated

its

resistance decreases. The resistance depends on the physical character of

photoconductive layer as well as on the dimensions of the cell and its geometric

configuration. The current depends upon the electricity voltage applied and it is of

the

order of the mA. When using photoconductive cell for a particular application it is


important to select the proper dark resistance, as well as suitable sensitivity. The

sensitivity is defined as :

Where,

∆R = Change in resistance; Ω

∆H = Change in irradiation; W/m-2

The spectral response of the sensor must match that of the light source. A Photo

conductor has a relatively large sensitive area. A small change in light intensity

causes

a large change in resistance. The relationship between irradiance and resistance is,

however not linear. It is closely an exponential relationship. The spectral response

of

cadmium sulphide cell closely matches that of the human eye and the cell is often

used in application where human vision is a factor, much as street light control or

automatic iris controls for cameras, to alter the bias of transistor or change the

gain of

an amplifier. Such circuits are used in automatic brightness composition of TV

receivers. Photoconductive cells are also used in bridge circuit applications, and

for

measurement of attenuation of light etc.

Experiment 16

AIM : To

study and


implement Characteristics of DC Motor (Speed / Vin).



2. Oscilloscope


Procedu

re :

1.

Make

the

connect

ions

accordi

ng to

the

Figure

30



4. Turn voltage POT slowly until the motor begins to rotate. And note down the

corresponding Reference voltage.

5. Increase the input voltage by slowly turning the Reference voltage POT. For

every one volt increment of the reference voltage (1v, 2v, 3v……….), record

the corresponding change in voltage on the socket 5 with the help of Digital

Voltmeter.

6. Note down all the readings in table given below

7. Switch Off the power switch.

8. Plot a graph on input voltage vs motor speed.


Experiment 17

AIM : To study and implement Bidirectional motor speed control

Equipments Needed :


2. Oscilloscope


Proc

edur

e :

1.

Make

the

conn

ecti

ons

acco

rdin

g to

the

Figu

re

32



4. Slowly move the pot and set the motor at particular speed.

5. Connect tp22 (Direction in) to tp6 (De-Bounce switch)

Observation :

Now when De-Bounce switch is pressed, motor will change its direction of rotation

and when De-Bounce switch is not pressed motor will rotation in its own direction.


Experiment 18

AIM:To study and implement Tachogenerator.

Equipments Needed :


2. Oscilloscope


Circuit diagram :

Procedur

e :

1.

Make the

connecti

ons

accordin

g to the

Figure

33

2.

Connect

the NV3000-Control System Lab to AC mains.


4. Connect tp21(IR Out) to CRO

5. On increasing the input voltage slowly by rotating the Reference voltage POT in

counter clockwise (CCW). For every 1volt increment of the reference voltage

(1v, 2v, 3v……….), you will see the corresponding square wave on CRO screen

that gives the measure of Reference voltage (input voltage).

Observation :

You will observe that with the increase in motor speed, pulse (square wave) widths

will decreases & vice versa. So, it is concluded that there is linear but inversely

proportional relationship between motor speed and pulse width.


Experiment 19

AIM :To study and implement Motor control using PWM method

Equipments Needed :



Circuit diagram :

Procedure :

1. Make the connections according to the Figure 34


3. Switch ON the trainer Power supply.

4. On slowly varying the POT in CCW (counter clockwise) direction to increase

the motor speed and CW (clockwise) to decrease the motor speed.

5. Connect the socket with +5v and ground to rotate the fan in one direction and

on

interchanging the terminals (+5v to Gnd & Gnd to +5v) the direction of rotation

will be in reverse.

Observation :

You will observe that speed of DC Motor will vary according to the change in

voltage.


Experiment 20

AIM: To study and observe Position control of DC Servo Motor

Equipments Needed :


2. PC Interface Module

3. Oscilloscope


5. One computer along with NV3000-Control System Lab Software.

Circuit diagram :

Proc

edur

e :

1.

Make

conn

ecti

ons

as

show

n in

Figu

re 35 between PC interface module and

trainer kit.

2. Switch ON the trainer power supply

3. Counter-check the trainer supply. Is it ON? If yes then ok and if not then

switch

it ON.

4. Now you are ready to “Run” the software given with the trainer.

5. Single left click on the “Connect” command button, so that all the application


buttons will get activated.

6. Now, single left click on the “Servo Motor” command button. A screen will

appear as shown in Figure 36

7. By changing the cursor position of scroll bar you can change the position of the

servo motor according to your requirement.

8. The change in angle position is shown in the form of an animated picture as

shown in Figure 36.

9. On connecting oscilloscope to digital output (D0) you will observe the change in

pulse width (ON time) with the change in angle.

10. Make an observation table to record the readings between ON time and angle

position.

Observation Table :

Experiment 21

AIM : To study and implement DC Motor Control-Open Loop

Equipments Needed :







Circuit diagram :

Procedur

e :

1.

Make

connecti

ons up

to

socket

23 & 24

as shown

in

Figure

37 between PC

Interface Module and NV3000-Control System Lab.

2. To built a Wave shaping circuit on the trainer bread board follow the following

steps :

• Insert transistor (LM3904) into the bread board properly.

• Connect a 1KΩ resistor with collector and a 100 KΩ resistor between 1 k &

base of transistor.

• Connect a 1 KΩ resistor and a 100 μf capacitor in series with base of the

transistor.

• Connect the output of IR sensor i.e., from socket-21 to base of the

transistor.

• Take the output between collector and 1 KΩ resistor and connect it to input

of F to V converter (Frequency to voltage) and connect emitter to gnd

(ground).

• Connect a supply of 5V dc between 100 K and 1 K resistor.

3. Before Switch ON the trainer power supply check once again the connection

properly and if you are sure about it then only switch ON the supply. Otherwise

components may burn.

4. Counter-check the trainer power supply. Is it ON? If yes then ok and if then

switch it ON.

5. Now, you are ready to “Run” the software given with the trainer.



7. Single left click on the “DC motor control” and a screen will appear on the

window as shown in Figure 38.

8. Choose “Open Loop Control” option.

9. Set the set-point value in set-point block according to your requirement.


10. Now move the cursor position in order to reach the set-point value until the

value of speed block matches or nearly equal to the set-point.

11. This method also called as Manual mode of controlling the system.

12. After completion of the experiment double click on “Disconnect” command

button given on the toolbar to stop the communication between PC and trainer.

Conclus

ion :

Observe

and

write,

how the

open

loop

charact

eristic

acting

on

sliding

the

scroll

bar in

order

to achieve the desired set-point or, the behaviour of the open loop? Whether you

are able to reach the set-point manually or not. And take the screen print of your

experiment and attach with your practical notebook as shown in FIG.

Experiment 22

AIM : To study and observe DC Motor Control-Close Loop

Equipments Needed :







Circuit diagram :

Proced

ure :

1.

Make

connec

tions

as

shown

in

Figure

39

betwee

n PC

Interface Module and

NV3000-Control System Lab.

2. To built a Wave shaping circuit on the trainer bread board follow the following

steps :

• Insert transistor (LM3904) into the bread board properly.

• Connect a 1KΩ resistor with collector and a 100 KΩ resistor between 1 KΩ

& base of transistor.

• Connect a 1 KΩ resistor and a 100 μf capacitor in series with base of the

transistor.

• Connect the output of IR sensor i.e., from socket-21 to base of the

transistor.

• Take the output between collector and 1 KΩ resistor and connect it to input

of F to V converter (Frequency to voltage) and connect emitter to gnd

(ground).

• Connect a supply of 5V DC between 100 KΩ and 1 KΩ resistor.


properly and if you are sure about it then only switch ON the trainer supply.

Otherwise components may burn.

4. Counter-check the trainer power supply. Is it ON? If yes then ok and if NO then

switch it ON.




7. Single left click on the “DC motor control” from the main menu then a screen


will appear on the window as shown in Figure 40.

8. Choose “Close Loop Control” option.

9. Set the set-point value in set-point block by clicking the up & down arrow as

shown in figure 40.

10. Now observe the change in the speed of DC motor with respect to the set-point

value in the Real – Time graph screen.

11. You will observe that the speed will change in accordance with the error (Err)

generated between the set-point (S.P.) and the feed-back (F.B.) value i.e., (Err

=

SP-FB).

12. In some cases the error will not be reduced to zero exactly because here we are

not using any controller (like PID). This experiment is to study the concept of

close loop. Here we can study the effect of feedback on a system.

13. This method also called as Automatic mode of controlling the system.

14. After the completion of an experiment double click on “Disconnect” button

given on the main menu.

Conclusion

:

Observe

and write,

how the

close loop

acting in

order to

achieve

the

desired

set-point

or, the

behaviour

of the

close

loop?

Whether the close loop is acting according to the

theory and the graphical representation (not exactly but it should be nearer to it)

or

not. Finally, take the screen print of your experiment and attach with your practical

notebook as shown in Figure


Experiment 23

AIM : To study and implement Temperature Control-Open Loop

Equipments Needed :






Circuit diagram :

Procedur

e :

1.

Make

connecti

ons as

shown in

Figure 41

between

PC

Interface

Module

and

NV3000-

Control

System Lab.

2. To do the connection as shown in Figure 41 you will need one relay (GoodSky-

GS-SH-205T) and one transistor (PNP type-2N3906). This component is

provided with this trainer, for pin configuration of relay and transistor refer

to

Figure 42 and Figure 43. Respectively, by using this components make the

circuit on breadboard given on the trainer as shown in Figure 41.






switch it ON.




7. Single left click on the “Temperature control” from the main menu then a

screen

will appear on the window as shown in Figure 44.


9. Set the set-point value in set-point block by clicking the up & down arrow

(temperature. range or set point value 25–70˚C) as shown in Figure 44.

10. To ON the heater click on the “check box” and to make OFF the heater

“uncheck” it. To reach the desired set point you have to ON and OFF the heater

as per requirement and the corresponding graph will be displayed on the Real-

Time graph screen is shown in the right side of Figure 44.

11. Now change the speed of DC motor by scrolling the cursor position to cool the

heater. It is mandatory that while changing the speed of motor turn OFF the

heater.

This method also called as Manual mode of controlling the system.

After the completion of an experiment double click on “Disconnect” button


Conclusion :

Observe and write, how the open loop characteristic acting on sliding the scroll bar

in

order to achieve the desired set-point or, the behaviour of the open loop? Whether

you


experiment and attach with your practical notebook as shown in Fig.


Experiment 24

AIM :To study and observe Temperature Control-Close Loop

Equipments Needed :






Circuit diagram :

Procedure

:

1.

Make

connectio

ns as

shown in

Fig.45

between

PC

Interface

Module

and

NV3000-

Control

System

Lab.

2. To do the connection as shown in Fig.45 you will need one relay (GoodSky-GS-

SH-205T) and one transistor (PNP type-2N3906). This component is provided

with this trainer, for pin configuration of relay and transistor refer to Fig.

42 and

43 respectively, by using this components make the circuit on breadboard given

on the trainer as shown in Fig. 45.






switch it ON.


6. Single left click on the “Connect” command button, so that all the

application


7. Single left click on the “Temperature control” from the main menu then a

screen

will appear on the window as shown in Fig. 46.


9. Set the Set-point value in set-point block by clicking the up & down arrow

(temp. range or set point value 25–70˚C) as shown in Fig. 46.

10. You will observe that the heater will switch ON/OFF in accordance with the

error generated between the set-point and the feed-back value and the

corresponding graph will be displayed on the Real-Time graph screen as shown

in the right side of Fig. 46.

11. The error will not going to be zero exactly because here we are not using any

controller (like PID). This experiment is to study the concept of close loop.

Here

we can study the effect of feedback on a system




Conclusion :

Observe and write how the close loops acting in order to achieve the desired set-

point

or, the behaviour of the close loop. Whether the close loop is acting according to

the


or


notebook as shown in Fig.


Experiment 25

AIM: To study and implement Light intensity control-Open Loop

Equipments Needed :





Circuit diagram :

Procedu

re :

1.

Make

connect

ions as

shown

in

Fig.47

between

PC

Interfa

ce

Module and


2. To complete the connection as shown in Fig.47 you will need an Op-Amp IC

(741). that is provided with this trainer. And for IC (741) layout and pin

configuration refer the Fig.48, by using this components make the circuit on

breadboard given on the trainer.



Otherwise components may get damage.


switch it ON.




7. Single left click on the “Light Intensity control” from the main menu then a

screen will appear on the window as shown in Fig. 49.



9. Now by scrolling the cursor position you can change the intensity of lamp-1 and

reach near to the set-point value and the corresponding change in graph will be

displayed on the Real-Time graph screen on the right side of Fig.49.

10. This method also called as Manual mode of controlling the system.



Conclusion :

Observe and write, how the open loop characteristic acting on sliding the scroll bar

in

order to achieve the desired set-point or, the behaviour of the open loop? Whether

you


experiment and attach with your practical notebook as shown in Fig


Experiment 26

AIM : To study and observe Light intensity control-Close Loop

Equipments Needed :





Circuit diagram :.

Procedure :

1. Make connections as shown in Fig.50 between PC Interface Module and


2. To complete the connection as shown in Fig.50 you will need an Op-Amp IC

(741). That is provided with this trainer. And for IC (741) layout and pin

configuration refer to the Fig.48, by using this components make the circuit on

breadboard given on the trainer.



Otherwise components may get damage.


switch it ON.


6. Single left click on the “Connect” command button, so that all the

application


7. Single left click on the “Light Intensity control” from the main menu then a


screen will appear on the window as shown in Fig. 51.


9. Now by scrolling the cursor position you can change the intensity of lamp-1 and

reach near to the set-point value and the corresponding change in graph will be

displayed on the Real-Time graph screen on the right side of Fig.51.

10. Now you will observe that the intensity of the Lamp-1 will change automatically

with respect to the set-point value and the corresponding change in graph will

be

displayed on the Real-time graph screen as shown on the right side of Fig.

11. In some cases the error will not be reduced to zero exactly because here we are

not using any controller (like PID). This experiment is to study the concept of

close loop. Here we can study the effect of feedback on a system.


13. After the completion of an experiment click on “Disconnect” button given on

the main menu.

Conclusion :

Observe and write, how the close loop acting in order to achieve the desired set-

point

or, the behaviour of the close loop? Whether the close loop is acting according to

the


or


notebook as shown in Fig.


Experiment 27

AIM : Calibration of RTD sensor

Equipments Needed :

NV3002 Mini Process Control Demonstrator trainer kit

NV3002 Mini Process Control Demonstrator software

2 mm Patch Chords

Low salinity mineral water (less than 2 litres.)

Connection diagram:

Procedure :

Make connections on trainer kit as shown in figure.

Connect mains chord and switch on power supply

Check whether the drain valve is closed or not, if it is open then close it surely

Fill tank with mineral water till LED at L1 glows. (This much amount of water is

required to turn ‘On’ heater)

Fill the tank up to L2

Open Software

Click ‘RTD Characteristics’ on home page.


Navigate ‘Open’ >> ‘Start’ (This will open USB port and starts acquiring

data).

Now temperature and resistance will show some reading.

Adjust pot given in ‘Signal Conditioning’ block on trainer kit until temperature

show 0 °C and resistance show 100 Ω

Observation :

This is calibration experiment. The signal conditioning block is calibrated to RTD

for further experiments.

Conclusion :

RTD gives 0 °C for the resistance value of 100 Ω


Experiment 28

AIM : Study RTD Characteristics

Equipments Needed :

25.NV3002 Mini Process Control Demonstrator trainer kit

26.NV3002 Mini Process Control Demonstrator software

27.2 mm Patch Chords

28.Low salinity mineral water (less than 2 litres.)

Connection diagram :

Procedure :

13.Make connections on trainer kit as shown in figure.

14.Connect mains chord and switch on power supply

15.Check whether the drain valve is closed or not, if it is open then close it surely

16.Fill tank with mineral water till LED at L1 glows. (This much amount of water is

required to turn ‘On’ heater)

17. Fill the tank up to L2

18.Open Software

19.Click ‘RTD Characteristics’ on home page.

20.Navigate ‘Open’ >> ‘Start’ (This will open USB port and starts acquiring

data).

21.Switch on heater.

22.‘Stop’ the process and ‘Close’ the USB port. After temperature goes to 70-75

°C


23.You can store the results by pressing ‘Save Record’; it will save data in Excel

format.

Observations :

figure shows the screenshot of this experiment. Typical characteristic based on

sample data is as shown in figure.

Conclusion :

Resistance of RTD is directly proportional to change in temperature. Prepare

following table.

Minimum Maximum

Resistance

Temperature


Experiment 29

AIM : Study the Open loop response of the process

Equipments Needed :

NV3002 Mini Process Control Demonstrator trainer kit

NV3002 Mini Process Control Demonstrator software

2 mm Patch Chords

Low salinity mineral water (less than 2 litres.)


Connection Diagram

Procedure :

Make connections on trainer kit as shown in figure

Connect mains chord and switch on power supply

Check whether the drain valve is closed or not, if it is open then close it surely

Fill tank with mineral water till LED at L1 glows. (This much amount of water is

required to turn ON heater)

Fill the tank up to L2

Open Software

Click ‘Process Control’ on home page.

A window will open; choose ‘Open Loop’ option

Navigate ‘Open’ >> ‘Start’ (This will open USB port and starts acquiring

data).


Check ‘Step Input to heater’ and ‘Stirrer’

A point will reach after which temperature starts decreasing. ‘Stop’ the process

and ‘Close’ the USB port.

Click ‘Plot’ to see fitted curve.

You can store the results by pressing ‘Save Record’; it will save data in Excel

format.

Observations :

You will get a response as shown in figure. A blue line is the real time response

while red line is approximated response of real time data.

Find out two values of time T1 and T2 as shown in figure the dotted curve shown is a

continuous function of the real time data.

After that find out following calculations:


2 1

2

3τ = T T

2

θ = T τ

Open Loop Transfer Function (OLTF):

s

pK e

1 s

From sample data T1 = 34 sec, T2 = 53 sec, Kp = 1.4

Therefore

3

τ = 53 342

τ = 28.5

θ = 53-28.5 = 24.5

-24.551.4 e OLTF =

1+28.55

Conclusion :

Find out step response of open loop system. Using open loop step response, find Open

Loop Transfer Function.


Experiment 30

AIM : Study of ‘On/Off’ controller using the software

Equipments Needed :

(hhhh)NV3002 Mini Process Control Demonstrator trainer kit

(iiii)NV3002 Mini Process Control Demonstrator software

(jjjj)2 mm Patch Chords

(kkkk)Low salinity mineral water (less than 2 litres.)


Procedure :

Make connections on trainer kit as shown in figure

Connect mains chord and switch on Power Supply

Check whether the drain valve is closed or not, if it is open then

close it surely

Fill tank with mineral water till LED at L1 glows. (This much

amount of water is required to turn ‘On’ heater); Fill the tank up to L2

Open Software. Click ‘Process Control’ on home page.

A window will open; choose ‘Close Loop’ >> ‘On/Off’ option

A window will popup asking for hysteresis settings. Set the value

of hysteresis range is (2-5)

Set the value of set point, the difference between set point &

current temperature should be at least 10 to see the performance of ‘On/Off’

control action


Navigate ‘Open’ >> ‘Save Parameters’ >> ‘Start’ (This will

open USB port and starts acquiring data).

You can store the results by pressing ‘Save Record’; it will save

data in Excel format. Before that ‘Stop’ the process and ‘Close’ the USB port.

Observations :

You will get a response as shown in figure. As it is only heating process you will

get peaks below the set point line.

Conclusion :

The heater gets on whenever temperature decreases below hysteresis line, and gets off

above set point line.


Experiment 31

AIM : Study of Ziegler- Nichols PID Controller tuning

Procedure :

Use open loop transfer function concluded in experiment number 3.

Prepare following table.

s

pK e

1 s

Open Loop Transfer Function

Observations :

Find out all the values given in table. These values are required in further

experiments like study of P, PI and PID control action. Following table is prepared

from sample data:

Controll

er

Kp

Td

P

p

28.50.8383%

K 1.424.5

-

PI

p

0.9 0.928.50.7575%

K 1.424.5

3.3 3.324.573.5 -

PID

p

1.2 1.228.50.9999%

K 1.424.5

2 224.549 24.512.25

2 2


Experiment 32

Objective :

Study of P-control action using the software

Equipments Needed :

41)NV3002 Mini Process Control Demonstrator trainer kit

42)NV3002 Mini Process Control Demonstrator software

43)2 mm Patch Chords

44)Low salinity mineral water (less than 2 litres.)


Procedure :

18.Make connections on trainer kit as shown in figure

19.Connect mains chord and switch on power supply


21. Fill tank with mineral water till LED at L1 glows. (This much amount of water is

required to turn ‘On’ heater); Fill the tank up to L2

22.Open Software. Click ‘Process Control’ on home page.

23.A window will open; choose ‘Close Loop’ >> ‘PID’ >> ‘P’ option

24.Set ‘P’ Parameter as per table, Set set-point

25.Navigate ‘Open’ >> ‘Save Parameters’ >> ‘Start’ (This will open USB port and

starts acquiring data).



format. Before that ‘Stop’ the process and ‘Close’ the USB port.

Observations :

You will get response of P-controller as shown in figure.

6. Find out transient response specifications from graph.

Rise Time, Peak Time, Delay Time, Maximum Overshoot, Settling time.

Specifications for sample data:

Rise Time (Tr): Time required to set-point rise from 0% to 100%, Tr = 120 sec

Delay Time (Td): Time required for the response to reach half the final value

the very first time. Td = 83 sec

Peak Time (Tp): Time required for the response to reach first peak of

overshoot.


Tp = 160 sec

Settling Time (Ts): Time required for the response to reach and stay within a

range about the final value of size specified by percentage of final value

(usually 2% or 5%).

Ts = 300 sec

Maximum Overshoot (Mp): Maximum overshoot is the maximum peak value.

Mp = 40 %

Find out Close Loop Transfer Function of the Process with P Controller.

For example:

Conclusion : Thus we performs P- Control action and close loop response with P

controller.


Experiment 33

AIM :Study of PI-control action using the software

Equipments Needed :






Procedure :

d) Make connections on trainer kit as shown in figure

e) Connect mains chord and switch on power supply

f) Check whether the drain valve is closed or not, if it is open then close it surely

g) Fill tank with mineral water till LED at L1 glows. (This much amount of water is


h) Open Software. Click ‘Process Control’ on home page.

i) A window will open; choose ‘Close Loop’ >> ‘PID’ >> ‘PI’ option

j) Set ‘P’, ‘Ti’ Parameter as per table, Set set-point

k) Navigate ‘Open’ >> ‘Save Parameters’ >> ‘Start’ (This will open USB port and


l) You can store the results by pressing ‘Save Record’; it will save data in Excel



Observations :


Find out transient response specifications from graph.






Peak Time (Tp): Time required for the response to reach first peak of

overshoot.

Tp = 183 sec


range about the final value of size specifies by percentage of final value


(usually 2% or 5%).

Ts = 360 sec


Mp = 9 %

Find out Close Loop Transfer Function of the Process with PI Controller.

For example:

Conclusion : Thus we performs PI- Control action and close loop response with PI

controller.


Experiment 34

AIM :Study of PID-control action using the software

Equipments Needed :






Procedure :

8. Make connections on trainer kit as shown in figure

9. Connect mains chord and switch on power supply


11. Fill tank with mineral water till LED at L1 glows. (This much amount of water is


12.Open Software. Click ‘Process Control’ on home page.

13.A window will open; choose ‘Close Loop’ >> ‘PID’ >> ‘PID’ option

14.Set ‘P’, ‘Ti’, ‘Td’ Parameter as per table, Set set-point

15.Navigate ‘Open’ >> ‘Save Parameters’ >> ‘Start’ (This will open USB port and





Observations :


Find out transient response specifications from graph.






Peak Time (Tp): Time required for the response to reach first peak of overshoot.

Tp = 350 sec


range about the final value of size specifies by percentage of final value

(usually 2% or 5%).


Ts = 460 sec


Mp = 6.2 %

Find out Close Loop Transfer Function of the Process with PID Controller.

For example:

Conclusion : Thus we performs PID- Control action and close loop response with PID

controller.


Experiment 35

AIM: Study the Industrial PID controller as ‘On / Off’ Controller

Equipments Needed :

11. NV3002 Mini Process Control Demonstrator

12. Patch cords

13. Mineral water (low salinity water)

Circuit diagram :

Connection diagram of Industrial PID controller as P-Controller


Procedure :

10. Connect the patch cords as shown in the figure.

11. Don’t connect the “Relay output” terminal to “Relay input” terminal, now.

12. Connect the mains cord and switch on the power supply of NV3002 Mini Process

Control Demonstrator.

13. Check whether water drain valve is closed properly.

14. Start filling water in tank until level 1 (L1) LED glows. Because heater will

start only when water is above L1 level.

15. To enter into the configuration set-up menu of industrial PID control, press

switches and simultaneously for 3 seconds and it display “SET 2” on

upper display and four zeros “0000” in the lower display. It tells that you

have entered into the menu.

16. Now, press 3 times. You will observe that upper the line of seven segment

display will show inpt (Input) and in the second line of seven segment display

select input sensor type as RTD by pressing or keys.

Now, press or until upper display line displays Pb (Proportional Band). At

this condition, press as well as or to set lower reading for

Proportional Band to “ Zero” i.e, 0000.

17. Now, press or until upper display line displays int.t (integral time),

and in lower display, set it by pressing as well as or , to 000.

18. Now, press or until upper display line displays der.t (differential

time), and in lower display, set it by pressing as well as or , to 000.

19. Now, press switches and simultaneously for 3 seconds to return to main

screen. Here upper display will show current process temperature i.e. measured

value.

20. In lower display we can set the required set point by pressing as well as

or .

21. Now, open the software. The main window of the software will appear on your

desktop as shown in figure below.


Stopwatch screen of the software

22. As you click on the “Stopwatch” option, the stopwatch screen will appear on

your desktop as shown in figure

23. In the table the 2nd column will records the difference between two intervals

and the 3rd column will record the total time elapsed.

24. Now, connect the “Relay output” terminal to “Relay in” terminal as shown in

the connection diagram.

25. Click on the “Start” option of the stopwatch screen.

26. Start note down the temperature and time in the interval of 10 seconds.

27. Take 30 to 40 readings or more for better result.

28. As the experiment is completed, close the stopwatch screen and then “Exit”

from the main window.

29. Now, switch off the power supply of the trainer and open all the connections.

30. Open the drain valve fully and drain the water completely from the tank and

don’t forget to close the valve.

31. Now, plot the graph using the readings you have noted down.


Observation :

1. After every 10 second interval note down the reading of temperature.

2. Plot the graph between temperature and time. Also note down the on time and off

time of heater.

3. Observe that, the on time of heater is more when the measure value is more drifted

from set point and it reduces when the measured value approaches near the Set

Point.

4. We can also change proportional band value to observe different readings.

Conclusion :

1. With increase in proportional band value, the measured value is shifted away from

the set point.

2. Heater will turn ‘On’ only when the lower level LED (L1) glows.

Note :

1. Do not overheat the heater; and the set-point value must not be above 800C at any

condition.

2. After completion of the experiment drain the water from the tank completely. And

if possible dry up the tank base with a piece of cloth to increase the tanks life.

3. Be careful while pouring water into the tank, such that no blot of water is

falling on the base and on the front panel of the trainer. It may cause electric

shock.


Experiment 36

AIM: Study of the Industrial PID controller as Proportional (P) Controller

Equipments Needed :


2. Patch cords


Circuit diagram :

Connection diagram of Industrial PID controller as P-Controller


Procedure :

1. Connect the patch cords.

2. Don’t connect the “Relay output” terminal to “Relay input” terminal, now.

3. Connect the mains cord and switch on the power supply of NV3002 Mini Process

Control Demonstrator.


5. Start filling water in tank until level 1 (L1) LED glows. Because heater will only

start when water is above L1 level.

6. To enter into the configuration set-up menu of industrial PID control, press

switches and simultaneously for 3 seconds and it display “SET 2” on upper

display and four zeros “0000” in the lower display. It tells that you have

entered into the menu.

7. Now, press 3 times. You will observe that upper the line of seven segment

display will show inpt (Input) and in the second line of seven segment display

select input sensor type as RTD by pressing or keys.

8. Now, press or until upper display line displays Pb (Proportional Band). On

this condition, press as well as or to set lower reading for Proportional

Band (for e.g. 005), as it was calculated in the “open loop response”

experiment.

9. Now, press or until upper display line displays int.t (integral time), and

in lower display, set it by pressing as well as or , to 000.

10.Now, press or until upper display line displays der.t (differential time),

and in lower display, set it by pressing as well as or , to 000.

11.Now, press switches and simultaneously for 3 seconds to return to main

screen. Here upper display will show current process temperature i.e. set point.

12.In lower display we can set the required set point by pressing as well as or

.

13.Now, open the software. The main window of the software will appear on your

desktop.



(e)As you click on the “Stopwatch” option, the stopwatch screen will appear on your

desktop.

(f)In the table the 2nd column will records the difference between two intervals and

the 3rd column will records the total time elapsed.

(g)Now, connect the “Relay output” terminal to “Relay in” terminal as shown in


(h)Click on the “Start” option of the stopwatch screen.

(i)Start note down the temperature and time in the interval of 10 seconds.

(j)Take 30 to 40 readings or more for better result.

(k)As the experiment is completed, close the stopwatch screen and then “Exit” from

the main window.

(l)Now, switch off the power supply of the trainer and open all the connections.

(m)Open the drain valve fully and drain the water completely from the tank and don’t

forget to close the valve.

(n)Now, plot the graph using the readings you have noted down.


Observation :

(a)After every 10 second interval note down the reading of temperature.

(b)Plot the graph between temperature and time. Also note down the on time and off

time of heater.

(c)Observe that, the on time of heater is more when the measure value is more drifted

from set point and it reduces when the measured value approaches near the Set

point.

(d)We can also change proportional band value to observe different readings.

Conclusion :

a) With increase in proportional band value, the measured value is sifted away from

the set point.

b) Heater will turn ‘On’ only when the lower level LED (L1) glows.

Note:

i. Do not overheat the heater; and the set-point value must not be above 800C at any

condition.

ii.After completion of the experiment drain the water from the tank completely. And

if possible dry up the tank base with a piece of cloth to increase the tank’s

life.

iii. Be careful while pouring water into the tank, such that no part of

water is falling on the base and on the front panel of the trainer. It may cause

electric shock.


Experiment 37

AIM :Study of the Industrial PID controller as Proportional Integral (PI) Controller

Equipments Needed :

NV3002 Mini Process Control Demonstrator

Patch Cords

Mineral water (low salinity water)

Circuit diagram :

Connection diagram of Industrial PID controller as PI- controller


Procedure :

14. Connect the patch cords.

15. Don’t connect the “Relay output” terminal to “Relay

input” terminal, now.

16. Connect the mains cord and switch on the power supply of

NV3002 Mini Process Control Demonstrator.


18. Start filling water in tank until level 1 (L1) LED glows.

Because heater will only start when water is above L1 level.

19. To enter into the configuration set-up menu of industrial PID

control, press switches and simultaneously for 3 seconds and it display

“SET 2” on upper display and four zeros “0000” in the lower display. It

tells that you have entered into the menu.

20. Now, press 3 times. You will observe that upper the line

of seven segment display will show inpt (Input) and in the second line of seven

segment display select input sensor type as RTD by pressing or keys.

21. Now, press or until upper display line displays Pb

(Proportional Band). On this condition, press as well as or to set lower

reading for Proportional Band (for e.g. 005), as it was calculated in the “open

loop response” experiment.

22. Now, press or until upper display line displays int.t

(integral time), and in lower display, set it by pressing as well as or ,

as it was calculated in the “open loop response” experiment.

23. Now, press or until upper display line displays der.t

(differential time), and in lower display, set it by pressing as well as or

, to 000.

24. Now, press switches and simultaneously for 3 seconds to

return to main screen. Here upper display will show current process temperature

i.e. Set point.

25. In lower display we can set the required set point by

pressing as well as or .

26. Now, open the software. The main window of the software will

appear on your desktop.



a) As you click on the “Stopwatch” option, the stopwatch screen will appear on your

desktop.

b) In the table the 2nd column will records the difference between two intervals and

the 3rd column will records the total time elapsed.

c) Now, connect the “Relay output” terminal to “Relay in” terminal as shown in


d) Click on the “Start” option of the stopwatch screen.

e) Start note down the temperature and time in the interval of 10 seconds.

f) Take 30 to 40 readings or more for better result.

g) As the experiment is completed, close the stopwatch screen and then “Exit” from

the main window.

h) Now, switch off the power supply of the trainer and open all the connections.

i) Open the drain valve fully and drain the water completely from the tank and don’t

forget to close the valve.

j) Now, plot the graph using the readings you have noted down.


Observation :

1. After every 10 second interval note down the reading of temperature.

2. Plot the graph between temperature and time. Also note down the on time and off

time of heater.

3. Observe that, the on time of heater is more when the measure value is more drifted

from set point and it reduces when the measured value approaches near the measured

value.

4. We can also change proportional band value to observe different readings.

Conclusion :

1. With increase in proportional band value, the measured value is shifted away from

the set point.

2. Heater will turn ‘On’ only when the lower level LED (L1) glows.

Note :

1. Do not overheat the heater; and the set-point value must not be above 800C in any

condition.

2. After completion of the experiment drain the water from the tank completely. And

if possible dry up the tank base with a piece of cloth to increase the tanks life.

3. Be careful while pouring water into the tank, such that no part of water is

falling on the base and on the front panel of the trainer. It may cause electric

shock.


Experiment 38

AIM : Study of the Industrial PID controller as Proportional Integral Derivative

(PID) Controller

Equipments Needed :


2. Patch cords


Circuit diagram :

Connection diagram of Industrial PID controller as PI- controller


Procedure :

Connect the patch cords.

Don’t connect the “Relay output” terminal to “Relay input” terminal,

now.

Connect the mains cord and switch on the power supply of NV3002 Mini

Process Control Demonstrator.

Check whether water drain valve is closed properly.

Start filling water in tank until level 1 (L1) LED glows. Because heater

will only start when water is above L1 level.

To enter into the configuration set-up menu of industrial PID control,

press switches and simultaneously for 3 seconds and it display

“SET 2” on upper display and four zeros “0000” in the lower

display. It tells that you have entered into the menu.

Now, press 3 times. You will observe that the upper line of seven

segment display will show inpt (Input) and in the second line of seven

segment display select input sensor type as RTD by pressing or

keys.

Now, press or until upper display line displays Pb (Proportional

Band). At this condition, press as well as or to set lower

reading for Proportional Band (for e.g. 005), as it was calculated in the

“open loop response” experiment.

Now, press or until upper display line displays int.t (integral

time), and in lower display, set it by pressing as well as or ,

as it was calculated in the “open loop response” experiment.

Now, press or until upper display line displays der.t (differential

time), and in lower display, set it by pressing as well as or ,

as it was calculated in the “open loop response” experiment..

Now, press switches and simultaneously for 3 seconds to return to

main screen. Here, upper display will show current process temperature

i.e. measured value.

In lower display we can set the required set point by pressing as well

as or .

Now, open the software. The main window of the software will appear on

your desktop.



As you click on the “Stopwatch” option, the stopwatch screen will

appear on your desktop.

In the table the 2nd column will record the difference between two

intervals and the 3rd column will record the total time elapsed.

Now, connect the “Relay output” terminal to “Relay in” terminal as

shown in the connection diagram.

Click on the “Start” option of the stopwatch screen.

Start note down the temperature and time in the interval of 10 seconds.

Take 30 to 40 readings or more for better result.

As the experiment is completed, close the stopwatch screen and then

“Exit” from the main window.

Now, switch off the power supply of the trainer and open all the

connections.

Open the drain valve fully and drain the water completely from the tank

and don’t forget to close the valve.

Now, plot the graph using the readings you have noted down.



LAB MANUAL

Version No. SWITCHGEAR & PROTECTION

Subject SWITCHGEAR & PROTECTION

Subject Code

EX-603

Scheme New

Class/Branch

VI SEM

Author Mr.Kritarth shrivastav



EXPERIMENT NO. 1

TO STUDY INSTANTANEOUS OVER CUURENT RELAY

AIM:- To study instentanous over current relay.

study the construction of relay.

Study the operating & deoperating relay.

Study the time vs current characteristics.

INSTRUMENTS REQUIRED:- Voltmeter, ammeter,loading CT, Autotransformer,instentanous

relay time rotary switch etc.

FEATURES:-

Continuously variable current setting

high drop-off/pick-up ratio

low transient over reach

wide setting range

PROCEDURE:- Study the operating & deoperating cuurent of relay.

Connection are made as shown as fig.

Set the desired current in the relay.

Switch on the MSB.

Now to set the fault current,we will be using current source for that press the

green butten.

Now decrese the current through current source.at certain current,the relay

will design or drop off.this current is called de energising current note it.


1. Observation table:-

Plug setting Operating current Deoperating current

(A)

2.

PS = 1A or 5v

PSM (A) = Fault current Operating time


29.Study the current vs time charac.

24.connection are made as shown in the dia.

25.Set the desired current in the relay.

26.Switch on MSB.

27.Now to set the fault current, we will be using current source.

Now reset the time totilizer by pressing red butten fitted on the totalizer &

press green butten.

RESULT:- From the current chara. It can be concluded that increse in PSM,

operating time decreses for very small rise in fault current above plug setting

= 1A the drop is extremly large.

Experiment NO:-2

AIM:- To study the operation of solid state over voltage/under voltage relay and

hence to obtain its inverse time/voltage characteristics.

Apparatus required: one over voltage relay, autotransformers,one(0-500 volts A C)

voltmeter and connecting wires all fitted in control panel.

Circuit diagram:

detai

ls of

the

relay

:

1)vol

tage

ratin

g-


400-500 volts.

2)settings range -stepless variable settting.

3)resting voltage- about 100 tyo 105 % of the voltage setting.

4)pick up voltage- equal to the set voltage with a minimum error of +/-5%.

5)Auxiliary unit and operational indicator- Auxiliary voltage=220 volts AC.

6)Accuracy – the operating value conferms to error clall index 5.0 per I.S. 3231/1965

at the voltage settings.

7)Application – the over voltage relay is used for protection of AC circuits, static

capacitors and machine such as indution motors.

8)in the over voltage relay 2 pot setting for particular voltage and pot no. 2 for

time setting.

Note: over voltage relay contacts are normally closed/normally open.

Procedure:

1)connect 3 ph with neutral to the control pannel strip.

2)set therelay voltage at 440 V and set the adjustment of voltage difference at

maximum .

3)Switch on MCB and push ON the control circuit.

4)Measure voltage of all the phase

Experiment no:- 3

AIM:- To study the operation of a non directional electro mechanical type over

current relay and hence to obtain its inverse time current characteristics.

Apparatus required ;- One non directional over current relay and control panel with time totalizer

fault creation panel , digital ammeter.

Theory:- This manual covers the commissioning and maintenance instruction for non directional

inverse time over current relays belonging to the CDG 11 family which are self

powered .there is no

need for any seprate auxillary DC or AC supply for these type of relays.these relays

are available in the standard current range of 50-200 % and 10-40% of 1A or 5A .

STANDARD I.D.M.T. RELAY:- idmt over current relay have been used extensively in UK

for protection of generators , tranformers and distribution network.

The minimum permissible time

grading between the over current relay at each section breaker is approx 0.5 sec.

With the increase in the system fault current.it is desirable to shorten the

clearance time of fault nearest to the power source in order to minimize damage.it is

thus necessary to reduce the errors which are disproportionately large ,when compared

to the clearance time of a C.B.


The operating time of an over current relay

tends to become aasymtotic minimum value with increase in the value of current .T his

is inherent in electromagnetic relays due

to saturation of magnetic circuits. So by varying the saturation , different

characterstics are obtained

if the core is made to saturate at large stage , it is called IDMT relay.

PROC

EDUR

E:-

S

w

i

t

c

h

o

n

t

he MCB.

Initially Toggle switch should be in OFF position.

Now to set desired fault current we will be using current source. For that Switch

on the toggle switch and move the current source till the desired fault current

is indicated on the ammeter it is quit possible that while adjusting the fault

current the FLAG of the relay might trip for that you have to reset the flag by

moving the marked shaft UPWARD for resseting the flag the toggle switch must be

brought in off position and the marked shaft move UPWARD.

Now the desire fault current is Set and relay flag RESET only when the disk has

move fully anti clockwise . Now move the toggle switch on OFF position and

press the green push button and timer counting will start and counting will

stop once the relay is operated. Note down the time in second.

Now plot the graph between time take for the relay to operate vs plug setting

multiplier at various T.M.S

GRAPH:-

(1) Agraph the oprating time vs relay current for any one plug setting current .

(2) A common graph of operating time vs multiplies of plug setting current is drawn

.

it can be seen that for a given TMS the operating time vs multiplies of plug

setting


current

change

rustics

is same

irrespe

ctive

of

pllug

setting

.

Experi

ment

no:-4

AIM:-

To

study

of

operation of electro-mechanical type under voltage relay and hence to obtain it`s

inverse time/voltage characteristics.

APARATUS REQUIRED:-

Under Voltage Relay(Electro-mechanical type).

Auto Transformer.

Toggle Switch.

Voltmeter 0-600v.

Time Totalizer

Time(Digital).

Control Circuit.

Transformer(P/T).

Connection wires.

DETAIL OF THE RELAY:-

Voltage rating-110 Volts

Setting range-50%+90% adjustable in 5 equal steps of 10%


PROCEDURE:

30.Switch on the MCB.

31.Initially Toggle switch should be in off position.

32.Now to set the desired fault voltage we will be using voltage source. For that

switch ON the Toggle switch marked as voltage set and move the voltage source

till the desired fault voltage is indicated on the voltmeter, it is quit

possible that while adjusting the fault voltage the FLAG of the Relay might

trip for that you have to RESETthe FLAG by moving the marked shaft UPWARD

denoted by (RELAY FLAG RESET) for resetting the FLAG the Toggle switch must be

brought in off position and the marked shaft move UPWARD.

33.Now the desire fault voltage is SET and relay FLAG RESET only when the disk has

move fully anti clock wise . Now move the Toggle Switch on OFF position and

press the green push button and timer counting will start and counting will

STOP once the relay is operated . Note down thw time in seconds.

34.Now for various T.M.S(Time Multiplier Setting) and P.S.M. (Plug Setting

Multiplier)

the time taken by the relay to operate at various fault voltage may be

note down.

28.Now plot the graph between time taken for the relay to opperate Vs Plug Setting

Multiplier

at various T.M.S.

TABULAR COLUMN:-


Graph:-

A graph of operation time V/S applied voltage for any one plug setting.

Experiment no:- 6

Aim: To obtain the characteristics of MCB relay.

Appratus Required: control panel with MCB

Circuit Diagram;


Proc

edur

e:

T

h

e

c

o

n

n

e

c

t

i

on are made as shown in the diagram.

Keep the auto Transformer at minimum position.

Now switch in the MCB.

Press the green button and switch on the MCB which is under test ,set the desired

current by varying the auto transformer .After setting the current,reset the

time tatalizer by pressing the red push mounted on the time totalizer.

Note down the time and current .The MCB will trip ,because this is bi-metalic

relay you have to wait for 3 to 4 minutes for next reading.

Take the reading and different current setting .

Draw a graph current v/s time

GRAPH:-

Agraph of current v/s time .it can be seen that the characteristics are inverse type

i.e time of operation is inversely proportional to the current.


The above

graph shows

two lines

at the same

same

current

depicting

the change

in tripping

time at the

same load

current

which shows

that the

tripping

time

reduced

after

loading the

thermal bimetallic relay.

The observation should be made at various multiples of rated current of

Bimetallic relay and noting the tripping time.

EXPERIMENT NO:- 7


MANUAL FOR PERCENTAGE BIASED DIFFERENTIAL RELAY

OBJECTIVE:- To determine the charactristic of the given differential relay and 2, apply the relay for the protection of a transformer against internal faults.

APPARTUS :- Prepare a list of equipment required from the given connection

diagram and note their ratings.

INTRODUCTION :- A differential relay has two electromagnets one attracting magnet and one stblizing magnet . Which actuate a balanced beam in opposite direction A

spring operates together with the stablizing magnet and the tension of the spring may

be altered and its position is graduated .This

construction is used in high speed differential relays Refer to . When used as a

differential relay one carries through current and and the other the difference

current. The force at each end of the beam is proportional to the square of the

current.

Differential protection :- The most positive way of protecting a

circuit against internal faults is to arrange relays to compare the current entering

and leaving it. Which should be the same under normal condition and during an

external fault any difference current must flowing into a fault within the protected

circuit .

When this system is applied to electrical equipment it is called differential

current protection and

afford protection against internal faults only.

Differential protection can be applied to generators motors transformers and

transmission lines when applied to transformer the ratio of transformer and the phase

shift in three phase shift transformer must be taken into account . In order to avoid


undesirable operation on heavy external fault faults due to current transformer

errors a restrainig winding is provided which is energies by the through current and

fewer turns than the operating.

Proced

ure:-

By

re

mo

vi

ng

th

e

to

p

li

d

ov

er

of

re

la

y

, adjust the bias top on both sides i.e. Either at 20% , 30% , or 40% for each

setting tripling time etc & as welll as minimum current operating setting.

Adjust relay oprating time which can be adjusted by moment of the disc

backstop which is controlled by rottating a knurled molded disc at the base of

the graduate time multiplier scale at present we have T.M.S. At 1

Adjust relay minimum operating current of the relay which is determined by the

tension of the disc control spring and can be adjust by rotating a molded disc.

Switch on the MCB and push green button, now adjust I1 and I2 each to be equal to

the set current by keeping continuosly variable knob is the control.

Keep I1 constant at this value and increase I2 through the Rheostate till your

control circuit and alarm indicate and take the regardind I1,I2 & I3

Increase I1 by 1A and then increase I2 through the rhestostate till your control

circuit trips.

Repeat till the current reacheas the rated value.

Repeat the above steps. Each time setting I2 to a constant value and adjust I1


till the control circuit trips Plots I1 vs I2 as in.

A transformer differential relay compare the current in the winding of the

transformer whose ratios are such as to make their of the transformer equal,

except for the magnetising current secondary currents foemer which is

relatively small the restrainig winding is provided in the relay to take care

of OT errors tap changing in the protected transformer and the effect of

magnetising and rush current of trsansformer

Dete

rmin

e

the

curr

ent

rati

o of

the

tran

form

etr

be protected.

Select suitable current transformer and connect as in set the operating

current so that the

relay will opereate for any internal fault but not operate for external

fault or overloads

Checks the operation of the relay by introducing fault.

Differential protection of transformer c.c. Contactor Holding coil If

internal fault to be

introduced.

OBSERVATION TABLE (I) 20% BIAS setting

S.N. Through current (A) Differential cut (A)

1

2

3

4

5

6


7

8

9

10

30% BIAS setting

S.N. Restraning current (A) Opereting cut (A)

1

2

3

4

5

6

7

8

9

10

(iii) 40% BIAS setting

S.N. Restraning current (A) Opereting cut (A)

1

2

3

4

5


6

7

8

9

10

EXPERIMENT NO:-9

AIM:- To obtain the characteristics of thermal bimetalic Relay.

Apparatus Required:-

Control panel with thermal.

Thermal relay provides overload protection & short circuit protection . As the

current increase beyond the rated value, the thermal relay can be reset by hand after

tripping, & removing the fault. There are two main operations. One is the thermal

operation with inverse time characteristics for overload protection & hammer trip

that assisted magnetic operation for short circuit operation.Thermal operation is

achieved with a bimetallic strip.when it heated by any over current flowing through

it & cause the contacts to open. Greater the inverse current,shorter the time

required to operate the thermal relay.

Proc

edur

e:-

(1)T

he

conn

ecti

on

are

made


as shown in fig.

(2)Keep the auto transformer at minimum position.

(3) Now switch on the M.C.B

(4) Press the green button & set the desired current by varying the auto

transformer.After setting the current, reset the time totalizer by pressing the

red push mounted on the time totalizer.

(5) Note down the time & current. The thermal relay will trip , because this is

bimetallic

relay you have to wait for 3 to 4 minutes for next reading or reset the relay

by press red nob fitted on the relay.

(6) take the reading & different current setting .

(7) Draw a graph current v/s time.

GRAPHS:-

A graph of current V/S time. It can be seen that the characteristics are inverse

type i.e time of operation is inversely proportional to the current.

The above

Graph shows

two lines at

the same

current

depicting

the change

in tripping

time at the

same load

current

which shows

that the

tripping

time reduced

after loading the thermal bimetallic relay. The observations should be made at

various multiples of rated current of bimetallic relay 7 noting the tripping

time.


BHOPAL INSTITUE OF TECHNOLOGY LAB MANUAL

Version No. 1ELECTRONIC INSTRUMENTATION

Subject ELECTRONIC INSTRUMENTATION

Subject Code EX604

Scheme New

Class/Branch VI SEM

Author Nirupa chaturvedi


LIST OF EXPERIMENTS

Experiment

No

NAME OF EXPERIMENT

1 (a) To Study of Input-Output characteristics of LVDT.

(b) Determination of sensitivity of LVDT.

2 (a) Study of Strain measurement using Strain gauges and

cantilever assembly.


(b) Determining sensitivity Strain Gauge.

3 To measure the value of unknown Resistance with the help of

wheat stone bridge.

4 To measure the value of unknown inductance with the help of

Maxwell's inductance bridge .

5 To measure the value of unknown capacitance with the help of

schering bridge .

6 To study the characteristics of photo voltaic cell.

7 To study and observe the characteristic of PIN Photo diode .

8 To study the characteristic of platinum RTD .

9 To study the operation of Analog to Digital converter .

10 To study the operation of digital to Analog converter .

Experiment : 1(a) Objective :

Determination of sensitivity of LVDT

Theory :

Sensitivity : The ratio of the change in LVDT output to a change in the value of the

measure and (displacement). Sensitivity is the smallest change in displacement, which

LVDT is able to detect. The output of LVDT is an alternating signal which is

rectified

and filtered to give DC output (Signal conditioner output). The DC output is

proportional to amplitude of alternating signal of LVDT.

Sensitivity S = AC output / Displacement (Vpp/ mm) OR

= DC output / displacement (Vdc/mm)

Procedure :



3. Note the reading of micrometer.

4. Measure the differential voltage between Test Point TP6 and TP7 with multi-


meter in mV range.


6. Repeat step 4.

(Differential voltage for 10 mm - Differential voltage

for 9 mm)

7. Calculate S = (10 mm - 9 mm)

= ……………. mV/mm

Exper

iment 1(b) Objective :

Study of Input-Output characteristics of LVDT

Apparatus Required:

LVDT kit

Multimeter

Connecting probes

Theory:

Linear variable differential transformers (LVDT) are used to measure displacement.

LVDTs operate on the principle of a transformer. As shown in figure 4, an LVDT

consists of a coil assembly and a core. The coil assembly is typically mounted to a

stationary form, while the core is secured to the object whose position is being

measured. The coil assembly consists of three coils of wire wound on the hollow

form. A core of permeable material can slide freely through the center of the form.

The inner coil is the primary, which is excited by an AC source as shown. Magnetic

flux produced by the primary is coupled to the two secondary coils, inducing an AC

voltage in each coil.

LVDT Measurement :

LVDT measures displacement by associating a specific signal value for any given


position of the core. This association of a signal value to a position occurs through

electromagnetic coupling of an AC excitation signal on the primary winding to the

core and back to the secondary windings. The position of the core determines how

tightly the signal of the primary coil is coupled to each of the secondary coils. The

two secondary coils are series-opposed, which means wound in series but in opposite

directions. This results in the two signals on each secondary being 180 deg out of

phase. Therefore phase of the output signal determines direction and its amplitude,

distance.

Displac

ing the

core to

the

left

causes

the first secondary to be more strongly coupled to the primary than the second

secondary. The resulting higher voltage of the first secondary in relation to the

second secondary causes an output voltage that is in phase with the primary voltage.

Procedure :


2. Make micrometer to read 10 mm .

3. Display will indicate 00.0. This is the position when core is at centre i.e

equal flux linking to both the secondary.

5. Rotating thimble again clockwise by 0.1mm. Reading will be taken after each 0.1

mm rotation until micrometer read 0 mm. This is positive end. At this point secondary

I have highest voltage and secondary II has lowest voltage.

6. Rotate thimble anticlockwise so that micrometer read 10 mm.

7. Rotate thimble anti clockwise so that micrometer read 10.1 mm. It will move

core 0.1 mm outside the LVDT and simultaneously observe reading on display.

It will indicate displacement from 10 mm position in negative direction. The

reading will be negative. It indicates that secondary II is at higher voltage

than

secondary I.

8.take reading of voltage generated in coil by connecting multimeter on output point

of LVDT kit.

9. Plot the graph between displacement (mm) indicated by micrometer and Display


reading (mm).The graph will be linear .

Observation Table:

S.no Displacement in micrometer Display displacement(mm) Generated voltage (mv)


Experiment 2(a)

Objective :

Determining sensitivity Strain Gauge

Theory :

Strain Gauge :

If a metal conductor is stretched or compressed, its resistance changes on account of

the fact that both the length and diameter of the conductor change. There is also a

change in the value of resistivity of the conductor when it is strained and this

property

is called piezoresistive effect. This is the principle of strain gauge. Strain gauge

is a


device the electrical resistance of which varies in proportion to the amount of

strain in

the device. The most widely used gauge is the bonded metallic strain gauge.

A strain gauge of length L, area A, and diameter D when unstrained has resistance

R = (ρL)/ A

When a gauge is subjected to positive strain, its length increases while its area of

cross section decreases, resistance of gauge increases with positive strain.

lateral strain − ∂D / D

ε = strain = ∆L/L

∆R / R

Gauge Factor = ∆L / L

Sensitivity :

The ratio of the change in auxillary output to a change in the value of the measurand

(strain). Sensitivity is the smallest change in strain, which the trainer is able to

detect.

Strain is directly proportional to weight.

Auxillary Output

Sensitivity S = Weight mV /gm

Procedure :


2. Measure the auxillary output.

3. Adjust Offset Null Adjust preset slowly to get 0 mV at auxillary output

terminal.

4. Place weight of 5 gm on cantilever and measure the auxillary output voltage by

multimeter in 200 mV range.

5. Repeat the above step by placing the weights of 10gm, 20 gms etc.

6. Calculate :

Auxillary Output

S= for above specified weights.

Weight

= ……………. mV/gm

Compare value of sensitivity for different weights.

Experiment :2(b)

Objective :

Study of Strain measurement using strain gauges and cantilever assembly



Strain gauge Kit

Connecting Probes

Theory:

Strain is the amount of deformation of a body due to an applied force. More

specifically, strain (ε) is defined as the fractional change in length, as shown

below.

∆L

ε= L

Strain can be positive (tensile) or negative (compressive). Although dimensionless,

strain is sometimes expressed in units such as in/in or mm/mm. In practice, the

magnitude of measured strain is very small. Therefore, strain is often expressed as

micro strain (µ-strain), which is ε x 10 -6.

Types of Strain gauges :

1. Unbonded metal strain gauges.

2. Bonded metal wire strain gauges.

3. Bonded metal foil strain gauges.

4. Vacuum deposited thin metal film strain gauges.

5. Sputter deposited thin film metal strain gauges.

Procedure :


2. Observe reading of the display. It should be 000.

If the display reading is not 000 then adjust offset null.

Take reading of strain directly from display board .

Observation Table:

S.no Weight in gm Strain


Result:

EXPERIMENT NO : 4


AIM :-To measure the value of unknown inductance with the help of Maxwell's

inductance bridge


Analog board

Dc power supply

function generator

2mm patch cord

Digital multimeter

Circuit

Diagram:

Theory :

This is the simplest method of comparing two inductance and to determine the values

off unknown inductance.Its first arm consist of a non inductive resistance R1 second

arm consist of a standard inducter in series with the noninductive resistance R3 is

used for resistance balance control third arm consist of an unknown inductors with

internal resistance Rx The balance can be obtained by varying resistance R2 of third

arm

L1 = inductor with unknown inductance

Rx= internal resistance

L3= standard inductor

R1,R3= non inductive resistance

At balance


Z1 Zx=Z2 Z3

the value of Lx can be calculated by the formula

Lx =L3R2/R1

Where Lis the value of unknown inductor and R is internal resistaance

PROCEDURE :-

Connect external power supply

Connect function generator probe in between Vin terminals

Make connection as shown in figure

Set 5Vpp,1 Khz input sinusoidal signal of function generator

Rotate the potentiometer R2 to find null or minimum sound is generated

Switch off the power supply and function generator

Take the reading of potentiometer resistance R2 between test points TP2 and

TP3

calculate the value of inductance Lxi and Rxi by there formula

Take the reading of unknown internal resistance Rx1 at socket a and test point

Tp2

Repeat the above steps for different values of Lx and Rx

OBSERVATION TABLE :

S NO RI R2 L3 LX=L3R2/R1 Rx=R2R3/R1

1

2

3

CALCULATION :

Measured value of R2 is .............ohm

Now measure the value of Lx by the formula

LX=L3R2/R1

Measured value of resistance Rx by the multimeter between socket .........ohm

Now measure the values of Rx by the formula

Rx=R2R3/R1


Result :

The Inductance for Lx is measured to be =.............micro henry

The internal Resistance is =.................ohm

EXPERIMENT NO :5

Aim:- To measure the value of unknown capacitance with the help of schering bridge

Apparatus Required :-

Analog board

DC power supply

Function generator

2mm patch cord

Digital multimeter

Theory :-

This bridge is the simplest method of comparing Two capacitance and to determine

unknown capacitance In first arm Zx consist of an unknown capacitor cx in series with

the resistance Rx and second arm consist of capacitor c3 and third arm consist of

variable resistance R2 and forth arm consist of a parallel combinaation of resistance

R 1 and capacitor c1 The balance can be obtained by varying the resistance R2of third

arm

At balance

Z1Zx=Z2Z3

The value of Rx can be calculated by formula

RX =R2C1/C3 The value of Cx can be calculated by the formula

Cx =R1C3/R2

Procedure :

Connect external powerr supply

connect functioon generator probe in between vin termminals

Make connectioon as shown in figure

Set 5Vpp,1 Khz input sinusoidal signal of function generatorr

Rotate the potentiometer R2 to find null or minimum sound is generated

Switch off the power supply and function generatorr

Take the readingg of potentiometer resistance R2 between test points TP2 and

TP3

calculate the value of capacitance Cxi and Rxi by there formula

Take the reading of unknown internal resistance Rx1 at socket a and test point


Tp2

Repeat the above steps for different values of Cx and Rx

Observaation table :-

S no R1 C1 C R RX=R2C1/C3 CX= R1C3/R2

1

2

3

Measured value of R2 is ...............ohm /k ohm

Now measure the value of Cx by the formula

CX= R1C3/R2 Now measure the value of Rx by the formula

RX=R2C1/C3 Result :-

The capacitance of capacitor CX= ...........micro farad

The effective resistance Rx= ...................ohm /K ohm

EXPERIMENT NO : 6

AIM:-To study the characteristics of photo voltaic cell

APPARATUS REQUIRED:-Experiment kit,connecting probes,digital multimeter.

Circuit Diagram:

THE

ORY

:-

The

pho

to

vol

tai

c

cell is a two layer device,It generate a voltage by electron/hole pair production

when the junction is exposed to light.these diffuse across the junction to set up

voltage. A current will flow if a resistance is placed across the terminal optimized

for energy production are often called solar cells This is an important class of

photo detectors. They generate a voltage proportional to EM radiation intensity.

They are called photo voltaic cells because of their voltage generating

characteristic when light falls on them. They in fact convert the EM energy into


electrical energy. They are active transducers ie they do not need an external source

to power them instead they generating voltage .

The cell is a diode constructing a pn junction between appropriately doped

semiconductors Photons striking cell pass through the thin p doped under layer

and are absorbed by electrons in lower layer causing a difference of potential to

develop across the junction. All photo voltaic cell have low but finite internal

resistance .When connected in circuit having some load resistance

photo voltaic the cell voltage is reduced some what from rated value .

The photo voltaic cell can operate satisfactorily in temperature range of 100 to

125 c The temp. changes have little effect on short circuited current but affect the

open circuited voltage considerably .The main advantage of the photo voltaic cell as

name implies are its stability to generate a voltage without any form of bias and

its extremely fast responses ,This means that it can be used as an energy converter

directlY

CHARACTERISTIC:-

PROCEDURE:-

35. Connect the circuit as shown in figure

36.The socket C of wire wound pot to +12 v

45)The socket A of Wire wound pot to 0v

46)The socket B of wire wound pot to input of powerr amplifier


47)The out put of power amplifier to input of Lamp filament

48)The other input of filament lamp to +ve input of Moving coil meterr '

49)The -ve input of moving coil meter to 0 v

50)Output of photo voltaic cell to 0v through a digital multimeter connected as

an ammeter at 2 mA range to measure short circuit current of photo voltaic cell

51)switch ON the power supply & set the 10 K ohm wire wound pot to minimum zero

output voltage from power amplifier

52)Place the opaque box over the plastic enclosure to exclude all the ambient

light Take reading of photo voltaic cell short circuit output current as

indicated on digital multimeter as lamp voltage is increased in 1 v steps

record the result in below table

OBSERVATION TABLE:-

Lamp filament

voltage

0 1 2 3 4 5 6 7 8 9 10

Short circuit

output current

(Micro A)

Open circuit

output voltage

Procedure:

29. Switch off the power supply &set the digital multimeter as voltmeter at

2/20 v dc range to read the open circuit output voltage

30.Switch on thee power supply and take the reading adding result to above table

31.switch off the power supply


32.Plot the graphs off photo voltaic cell short circuit current & open circuit

voltage against lamp filament voltage

RESULT :-characteristic of photo voltaic cell is plotted.

EXPERIMENT NO :7

AIM:-To study and observe the characteristic of PIN Photo diode .

Apparatus required :- Experiment kit,connecting probes

DIAGRAM:-


Theory :-

PIN photodiode differs from a standard PN photodiode by having layer of intrinsic

silicon.The intrinsic (I) region between normal P&N junction.The main improvement

of introuduction of I region is reducing capacitance of junction resulting

improvement of introuduction of I region is reducing capacitance of junction

resulting in fast response time .

When photodiode is reverse biased The reverse saturation current is depend

upon the intensity of incident light The photodiode Vs light relation ship is

linear over wide range in order to maintaine linearity the bias volatage

should be kept constant The output resistance of photodiode is very high of

the order of tens of mega ohms the DC resistance is the diode leakage

resistance and that too is very high This DC resistance depends upon the light

intensity.

CHARACTERISTIC:-


PROCEDURE:-

Connect the circuit as shown in the figure

socket c of wire wound pot to +12 v

socket A of wire wound pot to input of power amplifier

socket B of wire wound pot to input of power amplifier

Output of power amplifier to input of filament lamp

Other input of filament lamp to + ve input of moving coil meter

Connect -ve input of moving coil meter to 0v

Output of PIN photot diode to input of current amplifier this is used to

measure the current output of PIN photodiode

Output of current amplifier to input of DC amplifier

connect a digital multimeter as voltmeter on 20v dc range betwen output of DC

amplifier and 0v to measure the output voltage of DC amplifier

Place opaque box over the plastic enclosure to enclosure to exclude all ambient

light

Switch on the power supply and set the 10 k ohm wire wound pot.To minimum input at

DC amplifier

Take reading of Amplifier output voltage on digital multimeter as lamp voltage is

increased in 1v steps record the result in below table

Lamp filament

voltagee (v)

0 1 2 3 4 5 6 7 8 9

PIN Photodiode DC

amplifier output

voltage (v)


PIN Photodiode

Buffer output

voltage (V)


Change the current Amplifier to Buffer to measure output of PIN photo diode Take the

reading of PIN Photodiode output voltage as the lamp voltage is increased in 1v steps

record the result in table 4 remember to adjust the offset of DC amplifier is giving

zero output for zero input

Plot the graph between PIN photodiode current amplifier output voltage,buffer

amplifier output voltage &Lamp filament voltage.It should resemble the one given

below

Result :

chaaracterisic of PIN photodiode is studied


EXPERIMENT NO :8

Aim :-

To study the characteristic of platinum RTD

Apparatus required :- Experiment kit connecting probes digital multimeter

Theory:-

The variation in resistance of metal with variation in temperature is the basis of

of temprature measuremet in platinum rtd The metal generally used is platinum or

tungsten Platinum is especially suited for this purpose.as it can show limited

susceptibility to contaminaation all metal produce a positive change in resistance

with temprature This of course is the main function of an RTD.This implies that a

metal with high value off resistance should be used for RTD the requirment of the

conductor material to be used in RTD .The change in resistance of material per

unit change in temperature should be as large as possible .The material should

have high value of resistance so that minimum volume of material is used for the

construction of RTD .The resistance of material should have continoous and stable

relation ship with temperatu.Platinum or tungsten wire is wound on a former to give

a resistance in range of 10 K ohm depending upon application

Procedure :-

connect the circuit as shown in figure

The socket 'c'of slide potentiometer to +5v

The socket 'b' of slide potentiometer to output of platinum RTD connect digital

multimeter as

voltameter on 200 mv orr 2v DC range in between output of platinum RTD &ground

Set the 10 K slider resistance midway

Switch on the instrument check the output of IC temperature sensor for ambient

temperature by temperorily connecting DMM in 20 v DC range and find out the

resissstance in ohm for this particular temperaturee

Say for example ambient is 250c then platinum RTD reading as per chart is 109.73

switch on the power supply adjust the slider control of the 10 K ohm resistance to

the voltage drop across the platinum RTD is 109mv as indicatied by DMM This

calliberate the platinum RTD for an ambient temperature of 250c since the

resistance at 250c will be 109 ohms Note that the voltage reading across the RTD in


mV is the same as the RTD resistance jin ohms,since current flowing must be

0.109/109=1 mA

Connect the +12V supply to Heater element input and note the values of the voltage

across the RTD with the voltmeter to its 200mV or 2 Vrange (this representing the RTD

resistance ) and the output voltage from the IC temperature sensor with the voltmeter

set to its 20 v range (this representing the temperature of the RTD ) after each

minute given in below table

Time (minutes)

0 1 2 3 4 5 6 7 8 9

RTD

Temperaaature

RTD resistance (OHM

)

Switch of the power supply and disconnect heater element supply (+12)

Convert RTD temperature into 0c & add in above table

Plot the graph of RTD resistance in ohm against temperature in 0c .It should

resemble the one given below

Temperature Vs resistance Table

0 100.00 30 111.67

1 100.39 31 112.06

2 100.78 32 112.44

3 101.17 33 112.83

4 101.56 34 113.22

5 101.95 35 113.61

6 102.34 36 114.99

7 102.73 37 114..77

8 103.12 38 115.15

9 103.51 39 115.15

10 103.90 40 115.54

11 104.29 41 115.93

12 104.68 42 116.31

13 105.07 43 116.70

14 105.46 44 117.08

15 105.85 45 117.47

16 106.23 46 117.86

17 106.62 47 118.24


18 107.01 48 118.63

19 107.40 49 119.01

20 107.79 50 119.40

21 108.18 51 119.78

22 108.57 52 120.17

23 108.57 53 120.55

24 109.34 54 120.94

25 109.73 55 121.32

26 110.12 56 121.70

27 110.51 57 122.09

28 110.89 58 122.47

29 111.28 59 122.86

60 123.24

EXPERIMENT NO : 7

Aim :-To study the operation of analog to digital converter

Apparatus required :-Experiment kit,connecting probes,oscilloscope

Theory :-

The analog to digital conversion is a logical process that requires conceptually

two steps the quantizing and the coding. Quantization is the process that performs

the transformation of continuous signal in a set of discrete level soon afterward we

combine through the coding each discrete levels with a digital word.The digital to

analog converter performs the conversion in n steps where n is the converter

settlement in bits .The working principle of this converter is analogous to that of

weighing an object on laboratory balance using standard weights as reference

according to the binary sequence ¼,1/8,1/16............1/n Kilograms to perform

accurately we start with largest weight and go on decreasing order to one of

smallest value.

PROCEDURE :-


Connect the power supply to the trainer

Make the connection as shown in the figure

Connect the dc supply to the Vi of the converter

Keep the DC pot in counter clock wise position

Place the reset/count switch in reset position

Switch ON the power supply Keep the DC pot at mid position

To start conversion place the switch in count position the LED lit accroadding

to binary sequence

When the signal from the digital to analog converter goes over the input

signal the counter stops and LEDs show the binary conversion

Vary the DC pot and observe thee corresponding digital output. The converter

will follow the changes in analog signal without resetting the converter in

upward direction because the counter is configured as up counter only but to

observe the converted output when the input is decreased you have to reset

the converter

Observe on the oscilloscope the typical steps signal at the D/A output

Observe input voltage using digital multimeter and observe output LED

Repeat the test with the different values of input signal.

Result :- Analog to digital conversion is studied .

EXPERIMENT NO : 8

AIM :-

To study and observe the functional verification of a weighted resistor

digital to analog converter

APPARATUS REQUIRED:-Experiment kit, Connecting probes , Digital multimeter

THEORY:-

The simplest digital to analog converter is obtained by means of a summing

circuit with input resistance whose value depends on the bit weight that are


associated to. We obtain in this way the weighted resistors converter The switches

s3-s0 are driven from the digital information so that every resistance is connected

to reference voltage v ref or to ground in accordance with the fact that the

corresponding bit is at logical level 1 or 0

PROCEDURE:-

(llll) Connect the power supply to the board

(mmmm) Connect the D0-D3 of the logic switches to the corresponding jacks B0-B3

of the converter

set the switches S0-S3 to logic level 0

(nnnn) Connect the v Ref socket to +5v connect a multimeter as voltmeter for DC

to the output v0of the converters

(oooo) Switch the logic switches in binary progression &measure &recorded the

output voltage in corresponding of every combination of the input code

(pppp) With input code s3 s2 s1 s0=0000 the output voltage v0 has to be null

eventually little deviation against zero are due to operational amplifier

offset

(qqqq) Switch off the power supply

Result :-

Digital to analog converter is studied and output is verified

EXPERIMENT NO : 9

Aim :-

To study of weign bridge oscillator and effect on output frequency with variation in

RC combination

Apparatus required :-

Experiment kit


Connecting probes

DC power supply

2 mm patch cord

CIRCUIT DIAGRAM:-

Theory :-

The Weign Bridge is one of the simplest and best known oscillators and is used

extensively in circuits for audio applications Figure I shows the basic Wien bridge

circuit configuration On the positive side This circuit has only a few components

and good frequency stability Because of this simplicity and stability it is most

commonly used audio frequency oscillator The bridge has series RC network in one arm

and parallel RC network in the adjoining arm In the remaining two arms of the bridge

resistor R1 and Rf are connected .

The phase angle criterion for oscilaation is that the total phase shift around the

circuit must be zero

This condition occures only when the bridge is balanced that is at resonance.The

frequency of oscillation Fo is exactly the resonant frequency of the balanced Wien

bridge and is given by

F0 =0.159/RC


Procedure :-

1. Connect +12 v,-12 v DC power supply at their indicated position from

external source

2. Connect a 2mm patch cord between test point 1 and H

3. Switch on the power supply

4. Vary Rf pot to make gain (Rf/R1)greater than 2

5. Record the value of output frequency at test point G

6. Compare measured frequency with theoritically calculated value

7. Vary the gain pot of 470K to adjust the gain of the amplifier in case of

clipped wave form

8. Switch off the power supply

9. Connect a 2mm patch cord between test point A and B ,D and E


11. Switch off the power suppy

12. Connect a 2 mm patch cord between test point B and C ,E and F


Result :-weign bridge oscillator is studied and wave form is observed


LAB MANUAL

Version No. POWER SYSTEM-2

Subject POWER SYSTEM-2

Subject Code

EX701

Scheme New

Class/Branch

VII SEM

Author


bhopal institute of technology new lab manual

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