ab-30 v-i and i-v converter analog lab experiment board · pdf file ·...

AB-30V-I AND I-V CONVERTER

ANALOG LAB

EXPERIMENT BOARD

Ver. 1.0

An ISO 9001: 2000 company

94-101, Electronic Complex, Pardesipura INDORE-452010, India.

AB-30

Tel.: 91-731-2570301 Fax: 91-731-2555643Email: [email protected] Web: www.scientech.bz

Scientech Technologies Pvt. Ltd. 2

http://www.scientech.bz/

mailto:[email protected]

AB-30

V-I AND I-V CONVERTER

AB-30

TABLE OF CONTENTS

1. Introduction 3

2. Theory 5

3. Experiment 1 9To study Op-amp as Voltage to Current converter (Floating output and Grounded load output)

4. Experiment 2 13To study Op-amp as Current to Voltage Converter.

Datasheet 16

5. Warranty 18

6. List of service Centers 19

7. List of Accessories with AB-30 20


AB-30

INTRODUCTION

AB-30 is a compact, ready to use V-I AND I-V CONVERTER experiment board. This board is useful for students to understand the working and operation of op-amp as signal conveter. It can be used as stand alone unit with external DC power supply or can be used with SCIENTECH ANALOG LAB ST-2612 which has built in DC power supply, AC power supply, function generator, modulation generator, continuity tester, toggle switches, and potentiometer.

List of Boards :

Model Name

AB-01AB-02AB-03AB-04AB-05AB-06AB-07AB-08AB-09AB-15AB-16AB-17AB-18AB-19AB-21AB-22AB-23AB-25

AB-28AB-29AB-31AB-32 AB-33AB-34AB-38 AB-40AB-41

Diode characteristics (Si, Zener, LED)Transistor characteristics (CB NPN)Transistor characteristics (CB PNP)Transistor characteristics (CE NPN)Transistor characteristics (CE PNP)Transistor characteristics (CC NPN)Transistor characteristics (CC PNP)FET characteristicsRectifier CircuitsCommon Emitter AmplifierCommon Collector AmplifierCommon Base AmplifierRC-Coupled AmplifierCascode AmplifierClass A AmplifierClass B Amplifier (push pull emitter follower)Class C Tuned AmplifierPhase Locked Loop (FM Demodulator & Frequency Multiplier/Divider)Multivibrators (Astable / Monostable)F-V and V-F ConverterZener Voltage Regulator Transistor Series Voltage RegulatorTransistor Shunt Voltage RegulatorDC AmmeterDC VoltmeterOp-amp CharacteristicsDifferential Amplifier (Transistorized)


AB-30

AB-42AB-43AB-44

AB-45AB-51AB-52AB-53AB-56AB-65

AB-66

AB-67

AB-81

AB-82

AB-83

AB-84

AB-90AB-91AB-92AB-93

Operational Amplifier (Inverting / Non-inverting / Differentiator)Operational Amplifier (Adder/Scalar)Operational Amplifier (Integrator/Differentiator)Schmitt Trigger and ComparatorActive filters (Low Pass and High Pass)Active Band Pass Filter Notch Filter Fiber Optic Analog LinkPhase Shift OscillatorWien Bridge OscillatorsColpitt OscillatorKirchoff’s Laws (Kirchoff’s Current Law & Kirchoff’s Voltage Law)Thevenin’s and Maximum power Transfer TheoremReciprocity and Superposition TheoremTellegen’s TheoremTwo port network parameterOptical Transducer (Photovoltaic cell)Optical Transducer (Photoconductive cell/LDR)Optical Transducer (PhotoTransistor)

…. and many more


AB-30

THEORY

Operational amplifier is a direct-coupled high-gain amplifier usually consisting of one or more differential amplifiers and usually followed by a level translator and an output stage. The output stage is generally a push-pull or push-pull complementary-symmetry pair. An operational amplifier is available as a single integrated circuit package.

The operational amplifier is a versatile device that can be used to amplify DC as well as AC input signals and was originally designed for performing mathematical operations such as addition, subtraction, multiplication, and integration. Thus the name operational amplifier stems from its original use for these mathematical operations and is abbreviated to op-amp. With the addition of suitable external feedback components, the modern day op-amp can be used for a variety of applications, such as AC and DC signal amplification, active filters, oscillators, comparators, regulator, regulators, and others.

The op-amp may be used as a voltage to current converter and current to voltage converter for both ac as well as dc input signal. This is explained as follows

Voltage-to-Current Converter :

Op-amp circuit as voltage to current converter can be used in two configurations

1. Output load floating

2. Output grounded load

The very first configuration is op-amp with floating load (as shown in fig.1). In this circuit the feedback resistance will act as a load and as it is not connected to ground it will be called as floating.

The input voltage will be applied to the non-inverting input of op-amp and the feedback voltage across resistance RL will drive the inverting input terminal. This circuit will also be called as Current-series negative feedback amplifier as the feedback voltage across RL (applied to inverting terminal)


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depends on the output current iout and is in series with the input difference voltage Vid.

According to Kirchoff’s volyage law for input loop,

Vin = Vid + Vf

V-I Converter with output load floatingFig.1

But Vid = 0, and op-amp gain is considered large enough, hence

Vin = Vf

Vin = RL x iout

Or, Vin

iout = ------- ……………..(1) RL

This means in the circuit of fig.1 an input voltage Vin can be converted into an output current. If the RL is a precision resistance then output current will be precisely fixed.The second configuration of voltage to current converter is that in which one terminal of load is grounded and the load current is controlled be an input voltage. The circuit is as shown in fig.2.


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V-I Converter with grounded load Fig.2

According to Kirchoff’s Voltage law,

I1 +I2 =IL

Vin – V1 VO – V1

------------ + ------------ = IL

R RVin + VO – 2V1 = ILR

Therefore,

Vin + VO – ILR V1 = ----------------------

R

Since op-amp is connected in non-inverting mode, the gain of the circuit will be 2. then the output voltage is

VO = 2V1

= Vin + VO – ILR

Vin = IL x R Vin(r.m.s. value)

iL = ------- ……………..(2) R This means that the load current depends on the input voltage Vin and resistor R (all resistances are of equal value).

Applications of V-I Converters :

• Low voltage dc-to-ac voltmeter

• Diode matched finders

• Light Emitting Diodes (LEDs)

• Zener diode Testers.


AB-30

Current to Voltage Converter :

Op-amp circuit working as current to voltage converter is as shown in fig.3a. Here the input current which is to be converted into output equivalent voltage is applied to the inverting input terminal of op-amp and hence the circuit will work as inverting amplifier.

As we know the gain of inverting amplifier is given by,

Av = Vout = - RF

Vin R1

Therefore,Vout = -Vin x RF

R1

However, since V1 = 0V and V1 = V2

Iin = Vin / R1

And Vout = -Iin x RF ……………..(3)

Fig.3a I-V Converter Fig.3b

This means that if we replace the Vin and R1 combination by a current source Iin as shown in fig.3b the output voltage Vout becomes proportional to the input current Iin. In other words the circuit converts the input current


AB-30

into proportional output voltage. In our AB-30 board we have used the same logic.

Applications of I-V Converter :

• Sensing currents form photodetectors.

• In Digital – to – Analog Converters. EXPERIMENT 1

Object : To study the Op-amp as Voltage to Current Converter. Apparatus Required :

1. Analog board AB-30.

2. DC power supply +12V, -12V and variable dc supply of 0-5V from external source or ST-2612 Analog Lab.

3. Function Generator.

4. Ammeter.5. 2mm patch chords.Circuit Diagram :Circuit used to study the operation of V-I Converter is shown below :


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Fig. 4


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Procedure :

• Connect +12V and -12V dc power supplies at their indicated position from external source or ST-2612 Analog Lab.

• First we will study the V-I conversion for floating load configuration.

6. Connect a 0- 5V variable dc signal at the non-inverting input (between points a and gnd) of Voltage to Current converter circuit of AB-30 board. Initially set the voltage to 0V dc.

7. Connect ammeter between points e and Vout (this will connect a load at the output of op-amp and at the same time current flowing through the floating load can be observed on ammeter).

8. Gradually increase the variable dc supply at input from 0 to 5V (1V, 2V, 3V, 4V, 5V).

9. Note the respective output dc current displayed on ammeter in the following table. This will be the practical current value obtained from ammeter reading.

10. Also calculate theoretical value of output current form Eq.1 to crosscheck your results.

11. Remove dc signal applied at input and connect a 200Hz sine wave signal at the non-inverting input (between points a and gnd) of Voltage to Current converter circuit of AB-30 board. Initially set the voltage to 0Vp-p .


I/p DC voltage (Vin)

O/p DC Current (Practical value)

O/p DC Current from Eq.1

(Theoretical Value)

1V

2V

3V

4V

5V

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12. Gradually increase the variable dc supply at input from 0 to 5Vp-p (1Vp-p, 2Vp-p, 3Vp-p, 4Vp-p, and 5Vp-p).

13. Note the respective output ac current observed on ammeter in the following table. This will be the practical current value obtained from ammeter reading.


I/p AC voltage (Vin)

R.M.S. I/p Current

Vrms=Vp-p/ 22

O/p AC Current (Practical value)

O/p AC Current from Eq.2

(Theoretical Value)

1Vp-p

2Vp-p

3Vp-p

4Vp-p

5Vp-p

• Now we will study the V-I conversion for grounded load configuration.

1. Connect points e and Vout using 2mm patch cord.

2. Connect point a and b using a 2mm patch cord.

3. Connect ammeter between points c and d (this will connect a load RL

to the circuit and at the same time current flowing through the grounded load can be observed on ammeter).

4. Connect a 0- 5V variable dc signal at the input (between points Vin

and gnd) of Voltage to Current converter circuit of AB-30 board. Initially set the voltage to 0V dc.

5. Gradually increase the variable dc supply at input from 0 to 5V (1V, 2V, 3V, 4V, 5V).


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6. Note the respective output dc current displayed on ammeter in the following table. This will be the practical current value obtained from ammeter reading.


8. Remove dc signal applied at input and connect a 200Hz sine wave signal at the non-inverting input (between points a and gnd) of Voltage to Current converter circuit of AB-30 board. Initially set the voltage to 0Vp-p .

9. Gradually increase the variable dc supply at input from 0 to 5Vp-p (1Vp-p, 2Vp-p, 3Vp-p, 4Vp-p, and 5Vp-p).

10. Note the respective output ac current observed on ammeter in the following table. This will be the practical current value obtained from ammeter reading.


I/p AC voltage (Vin)

R.M.S. I/p Current

Vrms=Vp-p/ 22

O/p AC Current (Practical value)

O/p AC Current from Eq.2

(Theoretical Value)

1Vp-p

2Vp-p


I/p DC voltage (Vin)

O/p DC Current (Practical value)

O/p DC Current from Eq.1

(Theoretical Value)

1V

2V

3V

4V

5V

AB-30

3Vp-p

4Vp-p

5Vp-p

EXPERIMENT 2Object : To study the Op-amp as Current to Voltage Converter. Apparatus Required :

1. Analog board AB-30.

2. DC power supply +12V, -12V and variable dc supply of 0-5V from external source or ST-2612 Analog Lab.

3. Ammeter.4. Voltmeter / Oscilloscope.5. Function Generator.6. 2mm patch chords.Circuit Diagram :Circuit used to study the operation of I-V Converter is shown below :


AB-30

c

Fig. 4


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Procedure :• Connect +12V and -12V dc power supplies at their indicated

position from external source or ST-2612 Analog Lab.• Connect 5V dc signal at the input (between points f and gnd) of

Voltage to Current converter circuit of AB-30 board.

1. Connect ammeter between points g and h (this will display the current flowing through the op-amp, Iin ).

2. Connect Voltmeter between sockets Vout and gnd.

3. Vary the pot to vary the input current from 1mA, gradually upto 5mA (1mA, 2mA, 3mA, 4mA and 5mA) and note the respective voltage on voltmeter in the following table. This is the practical value of voltage.

4. Also calculate theoretical value of output voltage form Eq.3 to crosscheck your results.

5. Remove dc signal applied at input and connect a 200Hz sine wave signal between points f and gnd) of Current to Voltage converter circuit of AB-30 board. Set the voltage to 3Vp-p .

6. Vary the pot to vary the input current from 1mA, gradually upto 15mA (1mA, 3mA, 5mA…… 15mA) and note the respective voltage on voltmeter in the following table. This is the practical value of voltage.

7. Also calculate theoretical value of output voltage form Eq.3 to crosscheck your results.


I/p DC Current (Iin)

O/p DC Voltage (Practical value)

(Vout)

O/p DC Voltage from Eq.1 (Vout)

(Theoretical Value)

5mA

10mA

15mA

20mA

24mA

AB-30

DATASHEET


I/p AC Current (Iin) O/p AC Voltage (V) (Practical value)

(Vout)

O/p AC Voltage (V) from Eq.1 (Vout)

(Theoretical Value)

1mA

3mA

5mA

7mA

9mA

11mA

13mA

15mA

AB-30


AB-30

WARRANTY

1) We guarantee the instrument against all manufacturing defects during 24 months from the date of sale by us or through our dealers.

2) The guarantee covers manufacturing defects in respect of indigenous components and material limited to the warranty extended to us by the original manufacturer, and defect will be rectified as far as lies within our control.

3) The guarantee will become INVALID.a) If the instrument is not operated as per instruction given in the

instruction manual. b) If the agreed payment terms and other conditions of sale are not

followed.c) If the customer resells the instrument to another party.d) Provided no attempt have been made to service and modify the

instrument.

4) The non-working of the instrument is to be communicated to us immediately giving full details of the complaints and defects noticed specifically mentioning the type and sr. no. of the instrument, date of purchase etc.

5) The repair work will be carried out, provided the instrument is dispatched securely packed and insured with the railways. To and fro charges will be to the account of the customer.

DESPATCH PROCEDURE FOR SERVICE

Should it become necessary to send back the instrument to factory please observe the following procedure:

1) Before dispatching the instrument please write to us giving full details of the fault noticed.

2) After receipt of your letter our repairs dept. will advise you whether it is necessary to send the instrument back to us for repairs or the adjustment is possible in your premises.

Dispatch the instrument (only on the receipt of our advice) securely packed in original packing duly insured and freight paid along with accessories and a copy of the details noticed to us at our factory address.


AB-30

LIST OF SERVICE CENTERS

1. Scientech Technologies P. Ltd.90, Electronic Complex Ph: (0731) 5202959Pardesipura, Email: [email protected] INDORE – 452010

2. Scientech Technologies P. Ltd.First Floor, Ph.: (011) 26513912, 2686494314, Uday Park, Fax: (011) 26864943.NEW DELHI – 110049 Email: [email protected]

3. Scientech Technologies P. Ltd.New no.2, Old no.10, 4th street Ph.: (044) 52187548, 52187549

Venkateswara nagar, Adyar Fax: (044) 52187549CHENNAI – 600025 Email: [email protected]

4. Scientech Technologies P. Ltd. 202/19, 4th main street Ph.: (080) 51285011 Ganganagar, Fax: (080) 51285022 BANGALORE- 560032 Email: [email protected]

5. Scientech Technologies P. Ltd. 8,1st floor, 123-Hariram Mansion, Ph.: (022) 56299457 Dada Saheb Phalke Road Fax: (022) 24168767 Dadar (East) Email: [email protected] MUMBAI – 4000146. Scientech Technologies P. Ltd. 988, Sadashiv Peth, Ph.: (020) 24461673 Gyan Prabodhini Lane, Fax: (020) 24482403 PUNE – 411030 Email: [email protected]. Scientech Technologies P. Ltd SPS Apartment, 1st Floor Ph. +913355266800 2, Ahmed Maooji Street, E mail: [email protected]

Behind Jaiswal Hospital, Liluah, Howrah-711204

W.B.




AB-30

LIST OF ACCESSORIES

1. 2mm patch cord (red)…………………………………………..2 No.

2. 2mm patch cord (blue)…………………………………………4 No

3. 2mm patch cord (black)………………………………………..4 No


ab-30 v-i and i-v converter analog lab experiment board · pdf file ·...

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