ENGINEERING PRACTICES LABORATORY LAB MANUAL

(ELECGRICAL & ELECTRONICS)PREPARED BY

DEPARTMENT OF ELECTRICAL & ELECTRONICS ENGINEERING

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INDEX

S.NO TITLE OF THE EXPERIMENT PAGE NO

ELECTRICAL ENGINEERING PRACTICE

1. ELECTRICAL SYMBOLS, SAFETY ASPECTS OF ELECTRICAL WIRING AND EARTHING PRACTICES

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2. INTRODUCTION TO THE CONNECTION OF VOLTMETER, AMMETER AND MULTIMETER

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3. A.STAIRCASE WIRING

B. FLUORESCENT LAMP WIRING

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4. A.DOMESTIC LIGHTING CIRCUITS AND USE OF MEGGER

B. MEGGER TEST

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5. DIAGNOSING SIMPLE FAULTS IN GRINDER, MIXIE, IRON BOX, CEILING & TABLE FAN.

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6. INTRODUCTION TO TYPES OF FUSES, MCB WIRES AND CABLES

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ELECTRONICS ENGINEERING PRACTICE

1. BASIC ELECTRONIC COMPONENTS AND EQUIPMENTS WITHITS SYMBOLS

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2. IDENTIFICATION OF RESISTANCE AND CAPACITANCE 66

3. FAULT IDENTIFICATION AND TROUBLE SHOOTING OF CRO,FUNCTION GENERATOR AND POWER SUPPLY UNITS

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4. VERIFICATION OF LOGIC GATES 75

5. STUDY OF CRO 84

6. SOLDERING PRACTICE & DESOLDERING 92

COMPUTER PRACTICE

1. a) STUDY OF PC HARDWAREb) ASSEMBLING THE COMPUTER SYSTEM

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2. a) FORMATTING AND PARTITIONING HDDb) CONFIGURING CMOS-SETUP

C) INSTALLATION OF OS

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Figure 1.1 Basic Electrical Symbols

AIM:

To study the electrical symbols, Safety aspects of electrical wiring and earthing practices.

THEORY

1.1 CIRCUIT GROUNDS AND GROUNDING PRACTICES

This note attempts to clarify what is meant when the term "ground" is used in speaking of electrical circuits. Specifically the term refers to a current return path through the earth. Unfortunately, it has been loosely used to represent any type of current return path to an energy source. One of the first electrical symbols that students of electricity are introduced to is the symbol for "ground", shown in Figure 1.1.

This symbol represents a current return path through the earth to the low potential (voltage) side of an energy source. Frequently, however, it is used in electronic schematic drawings to indicate a current return such as a wire. In many cases it is used interchangeably with other symbols which, as we will see, are available to indicate specific returns. In any event, this use of the ground symbol can cause some confusion to the beginning student since many instruments provide an earth ground terminal.

1.2 THE CONCEPT OF "EARTH" GROUND

Early developers of electrical systems theorized that the earth was an electrically neutral body, i.e. an equal number of negative and positive charges are distributed throughout the earth at any given time. Being electrically neutral, earth is considered to be at zero potential and establishes a convenient reference frame for voltage measurements. Noting that voltmeters read only the difference in potential between two points, absolute measurements can be made by using earth as a reference.

A true earth ground, as defined by the National Electrical Code, physically consists of a conductive pipe or rod driven into the earth to a minimum depth of 8 feet. Figure 1.2 shows this concept, where the earth is used as the conductive current return path to the lowest potential point of the generating system.

1.3 SHOCK HAZARD PROTECTION USING EARTH GROUND

In instances where high voltages are required and chassis grounds or metal frames are used as return paths, hazardous conditions can be created if earth grounds are neglected. When the load circuit uses a metal enclosure as a chassis ground, resistive leakage or "sneak" paths can exist which result in high voltages between the enclosure and earth ground. (Leakage is any unsuspected, unwanted resistive path between two points.) If, inadvertently, a earth-grounded object, such as a water pipe, and the enclosure are simultaneously touched, a serious shock will result. Such a condition is illustrated in Figure1.3.

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ELECTRICAL SYMBOLS, SAFETY ASPECTS OF ELECTRICAL WIRING AND EARTHING PRACTICES

EXP.No.1

DATE:

5

Figure 1.2 Earthing Practice

Figure 1.3 A shock Hazard created by a leakage Path

Figure 1.4 Using Earth Ground to eliminate a shock Hazard

In Figure 1.4, the earth ground is connected to the load enclosure, placing the water pipe and the enclosure at the same potential, eliminating the shock hazard. Similar hazardous conditions can develop in the installation of household appliances. This is the reason that electrical codes require that appliance frames such as washers and dryers be connected to earth ground.

1.4 CIRCUIT GROUNDING

The ideal “single point ground “concept insures that no ground loops are created. As the name implies, all circuit grounds are returned to a common point. This concept is shown in Figure1.5. While this approach looks good on paper, it is usually not practical. Even the simplest circuits can have 10 or more grounds, and connecting them at a common point becomes a physical challenge.

2. LAB SAFETY

2.1 ACQUAINT YOURSELF WITH THE LOCATION OF THE FOLLOWING SAFETY ITEMS WITHIN THE LAB.

Fire extinguisher

First aid kit

Telephone and emergency numbers: Make sure that you have handy emergency phone numbers to call for assistance if necessary. If any safety questions arise, consult the lab instructor or staff for guidance and instructions.

Observing proper safety precautions is important when working in the laboratory to prevent harm to yourself or others. The most common hazard is the electric shock which can be fatal if one is not careful.

2.2 ELECTRIC SHOCK

Shock is caused by passing an electric current through the human body. The severity depends mainly on the amount of current and is less function of the applied voltage. The threshold of electric shock is about 1 mA which usually gives an unpleasant tingling. For currents above 10 mA, severe muscle pain occurs and the victim can't let go of the conductor due to muscle spasm. Current between 100 mA and 200 mA (60 Hz AC) causes ventricular fibrillation of the heart and is most likely to be lethal.

What is the voltage required for a fatal current to flow? This depends on the skin resistance. Wet skin can have a resistance as low as 150 Ohm and dry skin may have a resistance of 15 kohm. Arms and legs have a resistance of about 100 Ohm and the trunk 200 Ohm. This implies that 110 V can cause about 160 mA to flow in the body if the skin is wet and thus be fatal. In addition skin resistance falls quickly at the point of contact, so it is important to break the contact as quickly as possible to prevent the current from rising to lethal levels. Here are several safety precautions one should follow all the time:

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Figure 1.5 Concept of Single point Ground

Figure 1.6 Equipment grounding technique

2.3 EQUIPMENT GROUNDING

Grounding is very important. Improper grounding can be the source of errors, noise and a lot of trouble. Please consult the section of "Circuit Ground and Grounding Practice". Here we will focus on equipment grounding as a protection against electrical shocks. Electric instruments and appliances have equipment cases that are electrically insulated from the wires that carry the power. The isolation is provided by the insulation of the wires as shown in the figure 1.6(a) below. However, if the wire insulation gets damaged and makes contact to the case, the case will be at the high voltage supplied by the wires. If the user touches the instrument he or she will feel the high voltage. If, while standing on a wet floor, a user simultaneously comes in contact with the instrument case and a pipe or faucet connected to ground, a sizable current can flow through him or her, as shown in Figure 1.6(b). However, if the case is connected to the ground by use of a third (ground) wire; the current will flow from the hot wire directly to the ground and bypass the user as illustrated in 1.6(c). Equipment with a three wire cord is thus much safer to use. The ground wire (3rd wire) which is connected to metal case is also connected to the earth ground (usually a pipe or bar in the ground) through the wall plug outlet.

3. SAFETY PRECAUTIONS

STEP1: Do not work alone while working with high voltages or if you are using electrically operated machinery like a drill.

STEP2: Never leave high voltages on when you are not present. STEP3: Keep one hand in your pocket when probing high voltage circuits or discharging

capacitors. STEP4: Make sure all high voltage connections are adequately taped or otherwise

insulated to prevent accidental contact by you or neighboring students. STEP5: After switching power off, discharge any capacitors that were in the circuit. Do

not trust supposedly discharged capacitors. Certain types of capacitors can build up a residual charge after being discharged. Use a shorting bar across the capacitor, and keep it connected until ready for use.

STEP6: If you use electrolytic capacitors, do not put excessive voltage across them put ac across them connect them in reverse polarity

STEP7: Take extreme care using tools that can cause short circuits if accidental contact is made to other circuit elements. Only tools with insulated handles should be used.

STEP8: If a person comes in contact with a high voltage, immediately shut off power. Do not attempt to remove a person in contact with a high voltage unless you are insulated from them.

STEP9: In the event of an electrical fire do not use water. The lab fire extinguishers are specifically charged for electrical fires. Vacate the lab and close the door. Do not breathe toxic smoke or fumes. Ring the fire alarm, if one is available.

STEP10: Check wire current carrying capacity if you will be using high currents. The lab power wiring can only handle 15 Amperes continuously.

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STEP11: Make sure your leads are rated to withstand the voltages you are using. This includes instrument leads. Common wire insulation is rated for 600 Volts.

STEP12: Avoid simultaneous touching of any metal chassis used as an enclosure for your circuits and any pipes in the laboratory that may make contact with the earth, such as a water pipe. Use a floating voltmeter to measure the voltage from ground to the chassis to see if a hazardous potential difference exists.

STEP13: Make sure that the lab instruments are at ground potential by using the ground terminal supplied on the instrument

Result:

Thus the electrical symbols, Safety aspects of electrical wiring and earthing practices has been studied.

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Simple Circuit Diagram For ammeter and Voltmeter:

2.1 Circuit Diagram For ammeter and Voltmeter

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AIM:

To study the connection of Voltmeter, Ammeter and Multimeter.

APPARATUS REQUIRED:

1. Voltmeter, Ammeter and Multimeter2. 60w Bulb

3. Connecting Wire’s

THEORY

1. 1INTRODUCTION TO THE CONNECTION OF VOLTMETER AND AMMETER:

OHM’S LAW

Ohm’s Law is the relationship between the current I flowing through a resistance R and the potential drop across it V. The current is directly proportional to the potential difference across the resistance and is inversely proportional to the resistance,

As an alternative, Ohm’s Law may be stated as: The potential difference V across a resistance is directly proportional to the current I flowing through the resistance and the resistance R, or

V = IR

Ohm’s Law can be rearranged to define the resistance R so that

If the potential difference across the resistance is measured in volts (V) and the current flowing through the resistance is measured in amperes (A), then the resistance values will be in units of ohms.

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INTRODUCTION TO THE CONNECTION OF VOLTMETER, AMMETER AND MULTIMETER

EXPNo.2

DATE:

1. Analogy Multimeter 2. Digital Multimeter

Fig.2.2. Analogy Multimeter and Digital Multimeter

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2. INTRODUCTION TO MULTIMETER:

Multimeters are available in two types according to the way the reading is presented an analog multimeter uses a pointer to indicate a value and a digital multimeter gives a numeric value.

2.1 TYPES OF MULTIMETER

1. Analog Multimeter

2. Digital Multimeter

2.2 ANALOG MULTIMETER

GOOD POINTS

1. Continuous movement of the pointer permits monitoring of how the value changes.

BAD POINTS

1. In certain ranges the indicated value may differ widely from the actual value.

2. The use of many scales on the same instrument can cause confusion.

3. When resistance is to be measured, a 0Ω adjustment is necessary each time the range is changed.

4. The polarities of the test leads must be used correctly; otherwise reverse movement of the pointer can damage an analog multimeter.

2.3 DIGITAL MULTIMETER

GOOD POINTS

1. Generally provides high accuracy.

2. When the value is to be read, it is not necessary to convert the indicated value i.e. it allows the value to be directly read.

3. Each of the voltage ranges provides high internal resistance that are constant in value .therefore the low voltage range also provides high internal resistance ,which is a great advantage when measuring semiconductor circuits.

4. Proper polarities of the test leads do not cause concern. If the polarities are reversed, a “-” indication is displayed, clearly revealing that the polarities are reversed.

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Figure 2.3 Analogy Multimeter

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Figure 2.4 Digital Multimeter

2.4 ANALOGY MULTIMETER

The main points of an analog multimeter are briefly described below.

1. METER SECTION

The meter section consists of scales and pointer, the degree of deflection of the pointer enables the voltage value, current value and resistance value to be read. There are various kinds of scales:

Check the position of the range selector described below and read the scale that matches the position of the range selector.

DC V: Direct current Voltage

AC V: Alternating current Voltage

DC A: Direct current current

Ω : Resistance

2. RANGE SELECTOR

Select one of the measuring ranges of DC voltage (DC V).AC voltage (AC V), DC current (DC A) or resistance (Ω) by rotating this selector. In each of the ranges a finer range more suitable for measuring the desired value can be selected.

3. ZERO POSITION ADJUSTER

If the pointer is not at the zero position before a measurement it can be adjusted to the position using the zero position adjuster.

4. 0Ω ADJUSTER

After selection of any of the positions (×1, ×100, ×1K.etc.) of the resistance range by the range selector for measurement of a resistance ,put both test leads in contact with each other and adjust the pointer to the 0Ω position at this time.

5. MEASURING TERMINALS

The measuring terminals are the + and – (COM) terminals. Connect black test lead to the (COM) terminal.

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Figure 2.5 Measuring Terminals of Multimeter

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Figure 2.6 Illustrations of Multimeters

2.5 DIGITAL MULTIMETER

The major parts of a digital multimeter are briefly described below.

1. LCD METER SECTION

The LCD meter section indicates a number and polarity.

If the polarity of the input is negative, that display section presents a “-” indication. If an excessive input is applied, it indicates.

2. RANGE SELECTOR

Two types of range selectors available, types 1and 11.

Type 1 has the same range selector that is used for the analog multimeter. It changes measuring ranges as well as measuring functions.

Type 11 changes functions only (i.e., the measuring ranges are automatically changed according to the magnitude of the quantity being measured.)

3. POWER SWITCH

The power switch is used to turn the power supply of multimeter on and off. Generally the power switch is separate from the range selector. This is because a digital multimeter, unlike an analog multimeter, requires a power supply for the LCD meter and internal circuits.

4. HOLD BUTTON

Not all multimeters have this button. When a digital multimeter is used for measuring a value that makes minute changes, you cannot read the display because it changes too rapidly. In such a case press this button to put the display on hold to read the value. The display will remain while the button is being pressed.

5. MEASURING TERMINALS

The number and kind of terminals generally vary according to the model.

Whereas the black test lead is always connected to the – (COM) terminal, the red test lead should be connected to the terminal that matches the position where the range selector is placed.

OPERATING PROCEDURE

Current is the measure of the rate of electron "flow" in a circuit. It is measured in the unit of the Ampere, simply called "Amp," (A). The most common way to measure current in a circuit is to break the circuit open and insert an "ammeter" in series (in-line) with the circuit so that all electrons flowing through the circuit also have to go through the meter. Because measuring current in this manner requires the meter be made part of the circuit, it is a more difficult type of measurement to make than either voltage or resistance.

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Some digital meters, like the unit shown in the illustration, have a separate jack to insert the red test lead plug when measuring current. Other meters, like most inexpensive analog meters, use the same jacks for measuring voltage, resistance, and current. Consult your owner's manual on the particular model of meter you own for details on measuring current.

When an ammeter is placed in series with a circuit, it ideally drops no voltage as current goes through it. In other words, it acts very much like a piece of wire, with very little resistance from one test probe to the other. Consequently, an ammeter will act as a short circuit if placed in parallel (across the terminals of) a substantial source of voltage. If this is done, a surge in current will result, potentially damaging the meter:

Ammeters are generally protected from excessive current by means of a small fuse located inside the meter housing. If the ammeter is accidently connected across a substantial voltage source, the resultant surge in current will "blow" the fuse and render the meter incapable of measuring current until the fuse is replaced. Be very careful to avoid this scenario!

You may test the condition of a multimeter's fuse by switching it to the resistance mode and measuring continuity through the test leads (and through the fuse). On a meter where the same test lead jacks are used for both resistance and current measurement, simply leave the test lead plugs where they are and touch the two probes together. On a meter where different jacks are used, this is how you insert the test lead plugs to check the fuse: Build the one-battery, one-lamp circuit using jumper wires to connect the battery to the lamp, and verify that the lamp lights up before connecting the meter in series with it. Then, break the circuit open at any point and connect the meter's test probes to the two points of the break to measure current. As usual, if your meter is manually-ranged, begin by selecting the highest range for current, then move the selector switch to lower range positions until the strongest indication is obtained on the meter display without over-ranging it. If the meter indication is "backwards," (left motion on analog needle, or negative reading on a digital display), then reverse the test probe connections and try again. When the ammeter indicates a normal reading (not "backwards"), electrons are entering the black test lead and exiting the red. This is how you determine direction of current using a meter.

RESULT:

Thus the connection of Voltmeter, Ammeter and Multimeter has studied.

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Figure 3.1 Staircase light wiring

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1Φ, 230 V, 50Hz AC supply

3(a) STAIRCASE WIRING

AIM:

To control one lamp from two two-way switches in staircase light wiring.

COMPONENTS REQUIRED

SL.N0 Name of the Apparatus Range/ Type Quantity

1. Incandescent lamp 100W 1No

2. Lamp Holder Pendent Type 1No

3. SPDT Switch 230V,5A 1No

4. Wires 1/18 As per requirement

5. P.V.C Pipe 1/14 As per requirement

6. Wooden Board - 1No.

TOOLS REQUIRED

SL.N0 Name of the Tools Quantity

1. Combination Plier 1No

2. Connector Screw drivers 1No

3. Screw driver 1No

4. Electrician knife 1No

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TABULATION:

(i) Direct connection:

Position of S1 Position of S2 Condition of lamp

(ii) Cross Connection:

Position of S1 Position of S2 Condition of lamp

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THEORY:

One light point is to be controlled by two switches placed at two different places so that the light can be switched ON and OFF by either switch. This type of control of lamps is often used in staircase lighting, where it is necessary that the person going up the stairs should be able to switch ON and after reaching upstairs should be able to switch OFF the lamp.

PROCEDURE

The staircase light wiring is shown in the Figure (3.1).

STEP1: Two numbers of two way switches are used for staircase light wiring. STEP2: Two-way Switches have a central terminal.

STEP3: Central terminal of the first switch is connected to the upper terminal of the second switch.

STEP4: Similarly, the central terminal of second switch is connected to the lower terminal of the first switch.

STEP5: When the switch 1 is in ON condition and the switch 2 is in OFF condition, the lamps will not glow and vice-versa.

STEP6: When both the switches are either ON or OFF, the lamp will glow.

STEP7: Therefore, the lamp is controlled from two different switches.

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Result:

Thus the experiment of staircase light wiring has been tested.

TABULATION TO TESTING THE CHOKE

S.No. STATE OF THE LAMP GLOWCONDITION OF THE CHOKE

1 Normal glow Internal short circuit in choke

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Test Lamp 100W/240V

Figure 3.2 Test Circuit for Checking Choke

Choke 40W

N

L

1Φ 230 VOLT, 50HZ A.C SUPPLY

2 DimGood working condition of the choke

3 No glow Open circuit in the choke

3(b) FLUORESCENT LAMP WIRING

To construct a fluorescent lamp wiring using necessary components and to find the fault in fluorescent lamp.

COMPONENTS REQUIRED:

SL.N0 Name of the Apparatus Range/ Type Quantity

1. Fluorescent lamp Fixture 4ft 1No

2. Fluorescent lamp 40W 1No

3. Choke 40W,230V,5A 1No

4. Starter 1No

5. Wires 1/18 As per requirement

TOOLS REQUIRED:

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SL.N0 Name of the Tools Quantity

1. Combination Plier 1No

2. Connector Screw drivers 1No

3. Screw driver 1No

4. Electrician knife 1No

1. CONSTRUCTIONAL DETAILS OF FLUORESCENT LAMP

It consists of fluorescent tube, starter, choke, and two way connectors. They are explained as follows:

1.1 FLUORESCENT TUBE

The fluorescent tube of length varying from 2 to 4 feet is filled with low pressure argon and a drop of mercury.

Figure 3.4 Testing of tube

Figure 3.4 Testing of tube27

Figure 3.3 Testing of Starter

1.2 STARTERS

There are two types of starters.

(1) Glow type

(2) Thermal type

(1) GLOW TYPE

It consists of a pair of bimetal contacts sealed in a small glass bulb filled with argon gas. When supply is given, the whole mains voltage appears between the open contacts producing an arc discharge. The heat from the discharge closes the bimetal contacts, causing the pre-heat current to flow. The closer of contacts extinguishes the arc. The bimetal contacts cool and the contact again opens, make the lamp to strike. A small capacitor fitted between the contact connections outside the glass bulb avoids radio interference.

(2) THERMAL TYPE

It is also a pair of bimetal contacts, but these are initially closed and not open as in the glow starter. The contacts are sealed in a glass bulb together with a small heater coil. The bulb is filled with a suitable gas to improve the thermal link between the heater coil and the contacts. When supply is given, current flows through the lamp cathodes, the choke and the heater coil in the starter switch. The heater coil raises the temperature of the bimetal contacts and they separate, intercepting the current through the choke, and the consequent voltage pulse causes the lamp to strike. When the lamp starts, current flows through the starter heater and the bimetal contacts remain open. This form of switch is more complicated than the glow switch, but is useful where a larger preheating time is required. The therma starter is useful in fluorescent tubular lamps and sodium lamps.

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1.3 CHOKE COIL:

It is an iron cored inductance coil. It has two functions. They are:

(a) To provide a very high voltage (many times higher than supply voltage) to start the ionization process in the lamp.

(b) To limit the current through the circuit when the tube is operating.

1.4 CONDENSER:

The condenser is provided in the lamp in order to improve the power factor.

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Figure 3.5 Fluorescent Lamp

2. WORKING PRINCIPLES OF FLUORESCENT LAMP:

The fluorescent lamp circuit is given Fig (3.5). When supply is switched ON, the current heats the filaments initiating emission of electrons. After 1 or 2 seconds, the starter switch gets opened, making the choke to induce a momentary high voltage surge across the two filaments. Due to this, ionization takes place through argon gas.

Mercury vapour arc provides a conducting path between the electrodes. The starter used may be of thermal or glow type whose function is to complete the circuit initially for preheating the filaments and then to open the circuit for inducing high voltage across choke for initiating ionization.

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2.1 TESTING OF CHOKE:

Check the choke for its short and open with a test lamp as shown in Fig (3.2) and record the results and compare with the table.

2.2 TESTING OF STARTER:

To test the starter, connect the starter with a series test lamp as shown in the Fig.(3.3)

a. Observe the flickering of the lamp which indicates the good condition of the starter.

b. If there is no flickering in the test lamp the starter is defective.

2.3 TESTING OF FLUORESCENT TUBE:

To test the filament on both sides of the fluorescent tube for its continuity, make the connection as shown in the Fig (3.4). If the tube is in good condition, the lamp will glow normally. If the lamp is not glowing the tube is burnt out.

Discard the fluorescent tube, if there is open or fused filament in either side of the tube.

2.4 ASSEMBLING OF FLUORESCENT LAMP:

Assemble the following four fluorescent lamp parts follow the circuit given in Fig 3.5.

1. Fluorescent lamp frame

2. Choke

3. Starter

4. Two-way Connector

Fix up the Fluorescent tube in the connector fixed at the two ends of the frame.

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2.5 FAULT FINDING IN FLUORESCENT LAMP :( TESTING)

Connect the Fluorescent Lamp to a 230V, 1-Φ, 50 Hz AC supply. Now, the lamp will glow. If not, check for loose contact/ connection.

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Result:

Thus the experiment of assembling and testing of a fluorescent lamp circuit and fault finding has tested.

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Fig 4.1.Residential house wiring

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Exp NO:4 DOMESTIC LIGHTING CIRCUITS AND USE OF MEGGERDate:

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a) DOMESTIC LIGHTING CIRCUITS

AIM:

To construct and test basic household lighting using switches, fuse and indicator lamp.

COMPONENTS REQUIRED

1. Two switches2. Two Incandescent lamps3. Wires4. One wooden board5. Three clamps

THEORY:

Every conductor switches and other accessories should be of proper capacity to be capable of carrying the maximum current through it. All conductors should be of copper or aluminium. In power circuit, wiring should be designed for the load which it is supposed to carry. Power sub-circuits should be kept separate from lighting and fan sub- circuits. Wiring should be done on the distribution system with main and branch distribution board at convenient physical and electrical load centre. Wiring should look neat and have good appearance.

Wires should pass through a pipe or box and it should not twist or cross. The conductor is carried in a rigid steel conduit confirming to standards or in a

porcelain tube.

1.Switch:

The ON and OFF (i.e.,) the make and break of electrical connections to the load is done with the help of a switch. When the switch is ON, the circuit6 is alive and when the switch is OFF, the circuit is dead. The usual rating of switches used for domestic purposes are 5A and 15A. There are certain special switches used for domestic purposes like two way switches. Depending on shape and appearance they can be classified into tumbler switch.

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Fig .4.2.House wiring with fan tube light etc.

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2.Fuse:The main purpose of fuse is to isolate into the event of any short-circuit or

overloading or fault. It is always in the phase or line wore and is held in the fuse whenever excessive current flows or fault occurs. The fuse wire gets heated it melts and break the circuit. Hence the fuse should have low melting point. The material used for the fuse use copper, lead, tin, aluminium and alloy of tin and lead. Once fuse melts that to be replaced.

3.Energy meter:

An Energy meter is a device that measure the amount of electrical energy supplied to a residence or business. The meter fall into two basic categories – Electrochemical and electronic. The most common units of measurements on the electricity meter it is kwh.

4. Watt meter:

The traditional analog wattmeter is an electro dynamic instrument. This device consist of a pair of fixed coils known as current coil and a movable coil known as potential coil. The current coil is connected in series with the circuit, while the potential coil is connected in parallel also as an analog wattmeter. The potential coil carries a needle that moves over a scale to indicate the measurement. A current flowing through the coil generates an electromagnetic field around the coil. The strength of the field is perpendicular to the line and current and in phase with it. The potential coil has a general rule a high value resistor connected in series with it on an AC circuit. The deflection is proportional to average instantaneous product of voltage and current. Thus measuring true power and possible showing a different reading a stand alone voltmeters and stand alone ammeter in the same circuit.

PROCEDURE

Step 1: Fixed 1-phase energy meter, DP main switch and switch board on their on respective places.

Step 2: Make the connection as per circuit diagram.Step 3: Connected phase wire to lamp, socket, tube light and fan through switch and

connect neutral directly.Step 4: Now, switch on the power supply and job will the function.

RESULT

Thus the residential house wiring was constructed using switches, fuse, indicator and lamps.

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Fig .4.3.Megger

Fig .4.4.Insulation Resistance Test

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b)MEGGER TEST

AIM:

To measure the insulation resistance between conductor to earth by using meter.

APPARATUS REQUIRED:

Megger (500 V) – 1 no.

THEORY:

The megger is a portable instrument used to measure insulation resistance. The megger consists of a hand-driven DC generator and a direct reading ohm meter. A simplified circuit diagram of the instrument is shown in Figure 4.The moving element of the ohm meter consists of two coils, A and B, which are rigidly mounted to a pivoted central shaft and are free to rotate over a C-shaped core. These coils are connected by means of flexible leads. The moving element may point in any meter position when the generator is not in operation.

As current provided by the hand-driven generator flows through Coil B, the coil will tend to set itself at right angles to the field of the permanent magnet. With the test terminals open, giving an infinite resistance, no current flows in Coil A. Thereby, Coil B will govern the motion of the rotating element, causing it to move to the extreme counter-clockwise position, which is marked as infinite resistance.

Coil A is wound in a manner to produce a clockwise torque on the moving element. With the terminals marked "line" and "earth" shorted, giving a zero resistance, the current flow through the Coil A is sufficient to produce enough torque to overcome the torque of Coil B. The pointer then moves to the extreme clockwise position, which is marked as zero resistance. Resistance (Rl) will protect Coil A from excessive current flow in this condition.

When an unknown resistance is connected across the test terminals, line and earth, the opposing torques of Coils A and B balance each other so that the instrument pointer comes to rest at some point on the scale. The scale is calibrated such that the pointer directly indicates the value of resistance being measured.

1. Insulation resistance test (Earth to conductor):

To test insulation between circuit and earth, connect one terminal to the circuit and the other to a good earth. To test between a winding and its frame connect one terminal to the winding and the other to the frame. Having made the connections turns the handle at 160 rpm.

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Fig.4.6. Polarity Test

Fig 4.7.Continuity Test

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2. Insulation resistance test (conductor to conductor):

To test insulation between conductor and another one conductor. Connect one terminal to one conductor and other to another conductor. To test between a field winding and armature winding, one terminal to field winding and other to the armature. Having to made the connections turn the handle to about 160 rpm.

3. Continuity test (Conductor to conductor):

To measure continuity between a field winding and armature winding, one terminal to field winding (F1) and the other to the same field winding (F2) and similar to test the armature winding. Having made the connections turn the handle at about 160 rpm.

PROCEDURE:

Step 1: The connections are given as per in the figure.Step 2: Rotate the armature of the megger about 160 rpm.Step 3: Note down the reading of the megger.Step 4: Check the megger values are proper or not.

41

TABULATION:

Insulation Resistance Test:

S.No Connection Megger Value in Megaohms

Polarity test:

S.No Connection Megger Value in Megaohms

Continuity Test:

S.No Connection Megger Value in Megaohms

42

RESULT

Thus the insulation resistance between conductors to earth is measured and checked

the megger values by using megger.

43

Fig 5.1.Winding inside the fan

Fig 5.2.Dismantled view of Ceiling Fan

44

Ex.No:5Date:

DIAGNOSING SIMPLE FAULTS IN GRINDER, MIXIE, IRON BOX, CEILING & TABLE FAN.

AIM

Dismantling and studying of domestic appliance like electric iron, ceiling fan, Table Fan, grinder,mixie etc.

EQUIPMENT REQUIRED

Pleir, test pen, screw driver, knife, poker, spanner set 6-20,Ceilingfan,electric iron, Series testing board and multimeter.

CEILING FAN

Dismantling Procedure

Step 1 Remove the 3 blades first by opening screws which are fitted with body of the fan and blades.

Step 2 By giving support to the fan body remove the bolt from the ceiling hook.

Step 3 For opening the rod first remove check nut or quarter pin and then rotate the rod in anti-clock wise direction with hand removes it.

Step 4 Open the bottom end cover by opening the screws and with help of screw driver.

Step 5 Unscrew the screws of the top and bottom covers and remove then.

Step 6 When the bottom cover is removed the stationary portion on which winding coils are there will be visible. Take plier and put its leg into the vent ducts and place a screw driver in it and place it on the ground.

Step 7 Now rotate the capacitor side socket by inserting screw driver in the hole specially made for taking out wire for the connection.

Step 8 When the socket is out the top cover will come out. Thus the fan is dismantled as shown in the Fig 2

45

Fig .5.3.Dismantled view of Table Fan

46

TABLE FAN

Dismantling Procedure

Step 1. Open the front and rear grills.

Step 2. Remove the 3 blades first by opening screws which are fitted with body of the fan by removing the blade cap and rear grill nut.

Step 3. Remove the stator and rotor from the housing assembly.

Step 4. Remove the fan base from the fan stem.

Step 5. Dismantled view is shown in the Fig 3.

Procedure:( for checking the windings inside the fan)

Step 1 First of all dismantle all the parts of ceiling fan as stator, rotor, etc as shown in Fig 2 or 3.

Step 2 Now take the stator and remove all the coils of running winding and starting winding with the help of ensile.

Step 3 Now take one ceil of each winding as running winding and starting winding and count the total turn of the coil and its size with the help of micro meter.

Step 4 Now take the same size of wire and take the bobbin according to the slots as shown.

Step 5 Now fit the bobbin on the wooden block and fit it on the hand winding machine.

Step 6 Now make the coils according to counted turns. After making the coils, first put running winding coil in the inner slats of the fan stator.

Step 7 After that also put the coils of starting wires of running and starting winding and also ending wires of running winding and starting winding.

Step 8 At the last put out the four wires as starting wires of running and starting winding and also ending wires of running winding and starting winding.

Step 9 Now according to the circuit diagram make the connection of capacitor regulator after assembling the ceiling fan or dried after the varnishing.

Step 10 If fan rotates according to recommended R.P.M then winding is correct.

47

Fig .5.4. Winding inside the iron box

Fig .5.5 Dismantled view of Iron box.

48

IRON BOX:Procedure:

Step 1 Remove the back cover of handle and unscrew the power cord electric iron.Step 2 Remove the thermostat knob and check the circuit with series board.

Defect in Iron Box:If the iron is not heated:The reason can be any one of these

Broken wire, Fused heating element, Fused blown off (check fuse),Loose connection.(check & tighten the contacts),Thermostat not working.(only in automatic iron).

Press giving shock: 1. The heating element may be touching the sole plate.(insulation of former on

which it is wound is broken)2. Defective terminals.3. Earth wire of plug may be touching with Live wire.(check it &correct)

Fuse blown off as soon as iron is put on for use:1. Leaky iron.Short circuit in element.2. Sole plate under pressure plate leads to short circuit. (Check insulation between heater

elements & sole & pressure plate.)Remedies:1. Open circuit test:

First check the plug and socket with the help of series lamp. If it does not glow,the circuit is open, search it and rectify it.2. Short circuit test:

If lamp glows fully, there is heavy leakage& short circuit.3. Earth test:

In this test if lamp is glow bright, then earth is strong. If lamp is glow dull, then earth fault is there, check insulation fault & correct it.Precaution:1. Always use three core cables. The green core is earthed.2. Do not allow the cable to come in contact with hot iron.Do not over heat the iron.

49

Fig.5.6.Block Diagram for Mixie

Fig .5.7.Block Diagram for Grinder

50

POWER SUPPLY

SPEED CONTROL

UNIVERSAL MOTOR

FAN BLADES

POWER SUPPLY

SPEED CONTROL

1 ф INDUCTION MOTOR

GRINDING STONE

MIXIE & GRINDERProcedure:Step 1 Remove the screws at available at different points of the equipment.Step 2 Remove the motor present inside the caseStep 3 Dimantle the motor and check for windings.Step 4 If there is any fault in the winding change the windings with the same material

used.Step 5 Fit the motor as such as it was before.

ResultThus the various household appliances are dismantled and checked for faults.

51

Fig. 6.1.Various types of fuses52

Exp No:6Date:INTRODUCTION TO TYPES OF FUSES, MCB WIRES AND CABLESAIM:

To construct and test basic household lighting using switches, fuse and indicator lamp.

COMPONENTS REQUIRED

1. HRC fuse,Rewirable fuse2. MCB3. Wires4. Cables

1.FUSESThe fuse is a protecting device of simplest form. It consists of a small piece of metal.

When excessive current flows through it, the metal element melts and the current is interrupted and circuit gets disconnected from the supply. Thus it protects the circuit from dangerous excessive current. So fuse is used to interrupt a fault current. The fuse was invented by the scientist Edison in the year 1880. It is a simple protective device which works on the principle of current interruption, if current through it becomes excessive. Hence it protects the equipment from the effects of excessive high currents such as overheating, short circuiting, firing, damage etc. Its working and construction is very simple and can be designed very easily. A fuse is basically a small piece of metal connected between the two terminals mounted on the insulated base. The fuse is always connected in series with the circuit or appliance to be protected. A small piece of metal used in a fuse is called fusing element. The fusing element carries the normal working current safely but melts due to excessive current under abnormal conditions like overload and short circuit. The copper or lead-tin alloy is mostly used as fusing element. 1.1 Types of fuses The various types of fuses areExpulsion fuse: the expulsion fuse consist of modem cut-outs. In such fuse the arc occurring during the current interruption is extinguished by the expulsion produced by the arc. Rewirable fuse or semienclosed fuse: in such a fuse, the fuse element is placed in a serniclosed carrier. The fuse carrier can be pulled out and the fuse element can be replaced, after the fuse operationCartridge fuse: this fuse is totally enclosed fuse. The fuse element is placed in a totally enclosed carrier with two metal contacts provided on the two sides of a carrier. The entire cartridge is required to be replaced once fuse operates. Drop-out fuse: in such a fuse, the fuse carrier drops out,, once the fuse operates. The dropping out of fuse carrier provides the necessary isolation between the terminals. Liquid fuse: when fuse operates, in case of high currents, there exists an arc. The arc must be extinguished properly. The fuse in which the arc is extinguished using a liquid medium is called liquid fuse. The liquid medium used is generally oil. The various types of a liquid fuse are, i) oil-break circuit breaker fuse ii) oil-expulsion fuse iii) oil-blast fuse Open fuse: this fuse consists of a plain fuse wire and the fuse operates without any provision for extinguishing the arc.

53

Figure 6.2.Fuses

Figure 6.3.Cross section view of MCB

54

Striker fuse: in this fuse, there exists a combination of a fuse and a mechanical device. When the fuse operates, striker gets released under pressure which gives the tripping indication. Switch fuse: this fuse is a combination of a switch and a fuse. The combined unit is called switch fuse. HRC fuse: it is high rupturing capacity fuse. It is also called breaking capacity cartridge fuse. In such a fuse, the arc is extinguished with a help of a quartz sand powder. Such a powder provides very high resistance which helps to extinguish the arc. It is basically a low voltage fuse which is used for various distribution purposes. 1.2 Advantages of fuse

1. It is simplest and cheapest form of protecting device.

2. It requires no maintenance. 3. The operation of fuse is automatic while circuit breaker needs a tripping circuit to operate for its operation. 4. The minimum operating time can be made much smaller than that of circuit breaker. 5. Inverse time-current characteristic enables it to use for the overload protection. 6. With the help of a fuse, heavy currents can be interrupted without noise, smoke, gas and flame. The fuse can produce a current limiting effect under short circuit conditions. 1.3 Disadvantages of fuse

1. The fuse is required to be replaced or rewired after its operation. 2. The replacement or rewiring of fuse takes a lot of time. 3. Discrimination between fuses in series cannot be obtained unless there is much difference in relative sizes of the fuses. 4. The current-time characteristics cannot be always corelated with that of the protected equipment. 5. It is not possible to provide secondary protection to fuses.

2.MINIATURE CIRCUIT BREAKERSThe miniature circuit breaker (MCB) and moulded case circuit breaker (MCCB) offer

the overload protection characteristics of the fuse, good short circuit current limiting protection together with the advantage of a switching function. If correctly specified the MCB also has the added advantage of not requiring replacement after breaking a short circuit within its rated capability.

To achieve good fault current limitation the current-carrying contacts are arranged such that a magnetic repulsion effect proportional to the square of the fault current rapidly separates the contacts. An arc is then developed and extended across arc chutes (Fig. 11.16). Typical contact opening times are of the order of 0.5 ins and total fault clearance time 8 ins with a 50% reduction in prospective current peak for a modern IS kA MCB Such devices do not, therefore, meet the very fast fuse fault clearance times and prospective short circuit current limitation. Enhanced current limiting characteristics are, however, available from some manufacturers. Improved contact layouts and gas producing polyamide arc chutes which smother the arc give 0.2 ms opening times and total clearance times of only 2.5 ins.

55

Figure 6.4.Damaged wire.

56

For reliable repeated operation up to at least 10 times at a l5OkA prospective short circuit current, the installation protected by such an enhanced modern breaker would see less than 9% of the peak prospective current and less than 1.3% of the calculated thermal stresses. Careful MCB selection may therefore offer short circuit protection characteristics nearly as good as a fuse. Overload protection is achieved by the thermal distortion effects produced by a bimetallic element. After a preset, and often adjustable, amount of

Minature Circuit Breakers (MCBs), with latest technology, offer an ideal protection to the electrical distribution system. Whatever be the application, these MCBs offer perfect overload and short circuit protection in B, C and D types from 6A to 63A.

3.WIRES3.1 Material - Obviously the material used when making wire needs to be a good conductor of electricity, or more simply allow electricity to pass as unrestricted as possible. Due to this single restraint, metal naturally becomes the ideal wire material because most metals have very good conductivity, are readily available and are also relatively inexpensive. Aluminum, copper, nickel and certain metallic alloys such as steel make up the majority of what is used when making electrical wire. There are other metals such as silver and gold that are very good conductors but are much too expensive when used in the scope necessary to meet demand.

3.2 Solid vs. Stranded Wire - Solid wire is made up of a single piece of metal wire. Stranded wire is comprised of multiple (at least 7 strands) smaller diameters of wire that are bunched together to reach the necessary gauge. Both types of wire are fundamentally the same and are used to pass electricity from one point to another but each has separate advantages when used in certain circumstances. Solid wire is cheaper but also is far more rigid than stranded wiring. Stranded wire is flexible and provides more conductivity but again is more expensive.

3.3 Gauge - When discussing gauge of wire there is a helpful analogy in understanding why the size of wire is important. Think of the wire being used as a garden hose and the electricity passing through the wire as water. When you use a hose with a larger diameter you can push more water through the hose at any one time when compared with the smaller hose. This same principle holds true to the flow of electricity through wire. The larger gauge wire you use the more current or amperage you can pass through the wire at any one time. Physical constraints of the size wire you are using can have serious repercussions if not applied correctly ie. Forcing excessive electrical current through the wrong size "hose" can cause extreme heat or fire and/or short out your circuit with possibility of electrocution.

3.4 Insulation - Most wire is covered by a variety of different materials and this process is referred to as insulating or jacketing the wire. Wire insulation is always non-conductive and typically is comprised of glass, ceramic, rubber, plastic or a large variety of plastic polymers. Think of wire insulation as a protective blanket around the outside of metal wire itself. This protective coating ensures that the electrical current flowing through the center of the wire can only flow from one end to the other and not out of the middle into something else (another conductor, for example a piece of wire or your hand) near it. Insulation is important not only because it keeps the electricity from escaping it also serves an important secondary task by keeping other detrimental elements like moisture out of the wiring. Lastly, insulating the wire protects the internal metal from wear and prolongs the wire's lifespan.

57

Fig.6.5.Cables

Fig.6.6.Twisted pair cable

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3.5 Length - The length of wire is varied in every application it is used, thus length isn't a manufacturer variable but is still important for the resistance properties it exhibits. The longer the wire the more resistance the electricity flowing through that wire will experience. This is important because you may expect a certain amount of electricity to pass in theory but that amount of power will be less due to resistance inefficiencies.

4. ELECTRICAL CABLES

Electrical cables may be made more flexible by stranding the wires. In this process, smaller individual wires are twisted or braided together to produce larger wires that are more flexible than solid wires of similar size. Bunching small wires before concentric stranding adds the most flexibility. Copper wires in a cable may be bare, or they may be plated with a thin layer of another metal, most often tin but sometimes gold, silver or some other material. Tin, gold, and silver are much less prone to oxidation than copper, which may lengthen wire life, and makes soldering easier. Tinning is also used to provide lubrication between strands. Tinning was used to help removal of rubber insulation. Cables can be securely fastened and organized, such as by using trunking, cable trays, cable ties or cable lacing. Continuous-flex or flexible cables used in moving applications within cable carriers can be secured using strain relief devices or cable ties. At high frequencies, current tends to run along the surface of the conductor. This is known as the skin effect.

4.1Fire protection

In building construction, electrical cable jacket material is a potential source of fuel for fires. To limit the spread of fire along cable jacketing, one may use cable coating materials or one may use cables with jacketing that is inherently fire retardant. The plastic covering on some metal clad cables may be stripped off at installation to reduce the fuel source for accidental fires..

There are two methods of providing fire protection to a cable:1.Insulation material is deliberately added up with fire retardant materials2.The copper conductor itself is covered with mineral insulation (MICC cables)4.2Electrical cable types:Basic cable types are as follows:Based on construction and cable properties, they can be sorted into the following:• Coaxial cable• Mineral-insulated copper-clad cable• Flexible cables• Non-metallic sheathed cable • Metallic sheathed cable • Multicore cable (consist of more than one wire and is covered by cable jacket)• Shielded cable• Single cable (from time to time this name is used for wire)• Twisted pair

RESULT:

Thus the various types of fuses,wires,cables and MCB are discussed and studied.

59

Figure 1.1. Resistor symbols

Figure 1.2. Capacitor symbols

Figure 1. 3 .Inductor symbols

60

EX NO:1DATE:

BASIC ELECTRONIC COMPONENTS AND EQUIPMENTS WITH ITS SYMBOLS

AIM To study about the basic electronic components and equipments with its symbols.

APPARATUS REQUIRED

Resistors, Inductors, Capacitors, Transformers and Diodes

THEORY

A component may be classified as passive or active. Passive components are ones which cannot introduce net energy into the circuit they are connected to. They also cannot rely on a source of power except for what is available from the (AC) circuit they are connected to. As a consequence they are unable to amplify (increase the power of a signal), although they may well increase a voltage or current such as is done by a transformer or resonant circuit. Among passive components are familiar two-terminal components such as resistors, capacitors, inductors, and most sorts of diodes

Active components rely on a source of energy (usually from the DC circuit, which we have chosen to ignore) and are usually able to inject power into a circuit although this is not part of the definition. This includes amplifying components such as transistors, triode vacuum tubes (valves), and tunnel diodes.

1. RESISTORS

The electronic component known as the resistor is best described as electrical friction. When a person designs a circuit in electronics, it is often necessary to limit the amount of electrons or current that will move through that circuit each second. Thus the resistor is an electronic component that has electrical friction. This friction opposes the flow of electrons and thus reduces the voltage (pressure) placed on other electronic components by restricting the amount of current that can pass through it.

There are many different types of resistors used in electronics. Each type is made from different materials. Resistors are also made to handle different amounts of electrical power. Some resistors may change their value when voltages are placed across them. These are called voltage dependent resistors or nonlinear resistors. Most resistors are designed to change their value when the temperature of the resistor changes. Some resistors are also made with a control attached that allows the user to mechanically change the resistance. These are called variable resistors or potentiometers.

61

Figure 1.4 Symbols of diodes and transistors

Figure 1.5 Symbols of transformers

62

1.1. TYPES OF RESISTORS

1.1.1 .CARBON FILM RESISTORS

Carbon film resistors are made by depositing a very thin layer of carbon on a ceramic rod. The resistor is then protected by a flameproof jacket since this type of resistor will burn if overloaded sufficiently. Carbon film resistors produce less electrical noise than carbon composition and their values are constant at high frequencies. You can substitute a carbon film resistor for most carbon composition resistors if the power ratings are carefully observed. The construction of carbon film resistors requires temperatures in excess of 1,000 deg Celsius.

1.1.2. METAL OXIDE RESISTORS

Metal oxide resistors are also constructed in a similar manner as the carbon film resistor with the exception that the film is made of tin chloride at temperatures as high as 5,000 deg Celsius. Metal oxide resistors are covered with epoxy or some similar plastic coating. These resistors are more costly than other types and therefore are only used when circuit constraints make them necessary.

1.1.3 METAL FILM RESISTORS

Metal film resistors are also made by depositing a film of metal (usually nickel alloy) onto a ceramic rod. These resistors are very stable with temperature and frequency, but cost more than the carbon film or carbon composition types. In some instances, these resistors are cased in a ceramic tube instead of the usual plastic or epoxy coating.

1.1.4. THE VARIABLE RESISTOR

When a resistor is constructed so its value can be adjusted, it is called a variable resistor. First a resistive material is deposited on a non-conducting base. Next, stationary contacts reconnected to each end of the resistive material. Finally, a moving contact or wiper is constructed to move along the resistive material and tap off the desired resistance. There are many methods for constructing variable resistors, but they all contain these three basic principles.

2. CAPACITORS

Capacitors are components that can store electrical pressure (Voltage) for long periods of time. When a capacitor has a difference in voltage (Electrical Pressure) between its two leads it is said to be charged. A capacitor is charged by forcing a one way (DC) current to flow through it for a short period of time. It can be discharged by letting an opposite direction current flow out of the capacitor.

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When a voltage (Electrical Pressure) is placed on one lead with respect to the other lead, electrons are forced to “pile up” on one of the capacitor’s plates until the voltage pushing back is equal to the voltage applied. The capacitor is then charged to the voltage. If the two leads of that capacitor are shorted, it would have the same effect as the capacitor would rapidly discharge and the voltage across the two leads would become zero (No Charge).

Thus a capacitor stores electrical energy when charged by a DC source. It can passalternating current (AC), but blocks direct current (DC) except for a very short charging current, called transient current.

There are many different types of capacitors used in electronics. Each type is made from different materials and with different methods. Capacitors are also made to handle different amounts of electrical pressure or voltage. Each capacitor is marked to show the maximum voltage that it can withstand without breaking down. All capacitors contain the same fundamental parts, which consist of two or more conductive plates separated by a nonconductive material. The insulating material between the plates is called the dielectric.

3. INDUCTORS

The electronic component known as the inductor is best described as electrical momentum. In our water pipe analogy the inductor would be equivalent to a very long hose that is wrapped around it many times .If the hose is very long it will contain many gallons of water.

When pressure is applied to one end of the hose, the thousands of gallons of water would not start to move instantly. It would take time to get the water moving due to inertia (a body at rest wants to stay at rest). After a while the water would start to move and pick up speed. The speed would increase until the friction of the hose applied to the amount of pressure being applied to the water. If you try to instantly stop the water from moving by holding the plunger, the momentum (a body in motion wants to stay in motion) of the water would cause a large negative pressure (Suction) that would pull the plunger from your hands.

Since Inductors are made by coiling a wire, they are often called Coils. In practice the names Inductor and Coil are used interchangeably. The nature of a Coil in electronics follows the same principles as the coiled hose analogy. A coil of wire will pass DC and block AC. Recall that the nature of a Capacitor blocked DC and passed AC, the exact opposite of a coil. Because of this, the Capacitor and Inductor are often called Dual Components.

Thus the Inductor prevents current from making any sudden changes by producing large opposing voltages. Magnetic coupling can be used to transform voltages and currents, but power must remain the same. Coils and transformers can be used to select frequencies.

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4. TRANSISTORS

The transistor is best described as a device that uses a small amount of current to control a large amount of current (Current Amplifier). A small amount of “Base Current” pushes on the L1 portion of the lever arm forcing check valve D1 to open, even though it is “reverse biased” (pressure is in direction to keep check valve shut). Keep in mind the base current would not start to flow until the check valve D2 allowed current to flow. If the current ratio through D1 and Base was equal to the lever arm advantage, then I1 / Ib = L1 / L2. Call this ratio Beta (b) and let L1 = 1 inch and L2 = 0.01 inch. Then b =100 and I1 will be 100 times Ib. Since both currents must pass through D2, I2 = I1 + Ib. These same principles apply to a silicon NPN transistor. I1 becomes collector current (IC), and I2 would be emitter current (IE). b = IC / IB and IE = IB + IC.

5. TRANSFORMERS

A transformer is an AC device which transfers the power from one circuit to the other circuit without any change in its frequency. If the generator voltage is continuously changing will produce a current that changes with time. It has primary and secondary windings where its primary acts as input and the output power is obtained across the secondary terminals. If the generator voltage is continuously changing will produce a current that changes with time. This changing current in the center coil will produce similar currents in both of the end coils. Since the bottom coil has twice the number of turns (twice the magnetic linkage), the voltage across this coil will be twice the generator voltage. The power in an electronic device is equal to the voltage across the device times the current through the device (P=VI). If the voltage doubles on the bottom winding, then the current must become 1/2 due to the law of conservation of power (Power cannot be created or destroyed, but can be transformed from one state to another). Since the bottom coil is wound in the same direction as the generator coil, the voltage across the coil (top wire to bottom wire) will be the same polarity as the generator voltage. The top coil is wound in the opposite direction forcing the core magnet rotation (Called flux by the Pros) to push the current in the opposite direction and produce a voltage of the opposite polarity. Since the numbers of turns in the top coil are the same as the generator coil, the voltage and current (Power that can be taken from the coil) will also be equal. This ability to transform AC voltages and AC currents influenced early experimenters to call this device a Transformer.

RESULT

Thus the basic electronic components and its symbols were learned.

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Table.1 Color code chart of resistor

S.I No Color First Band Second Band Third Band Multiplier Tolerance

1

2

3

4

5

6

7

8

9

10

11

12

Black

Brown

Red

Orange

Yellow

Green

Blue

Violet

Grey

White

Gold

Silver

0

1

2

3

4

5

6

7

8

9

0

1

2

3

4

5

6

7

8

9

0

1

2

3

4

5

6

7

8

9

1 ohm

10 ohm

100 ohm

1 Kilo ohm

10 kilo ohm

100 kiloohm

1Megaohm

10Megaohm

0.1

0.01

1%

2%

0.5%

0.25%

0.10%

0.05%

5%

10%

EX NO:266

DATE:

IDENTIFICATION OF RESISTANCE AND CAPACITANCE

AIM

1. To identify and measure the values of resistors using color coding.2. To identify and verify the capacitor values.

APPARATUS REQUIRED

Resistors, capacitors, multimeter

THEORY

Resistor values are always coded in ohms (symbol Ω) and capacitors in Farads (F)

Band A is first significant component value.

Band B is the second significant component value

Band C is the decimal multiplier•

Band D if present, indicates tolerance of value in percent (no color means 20%)For example, a resistor with bands of yellow, violet, red, and gold will have first digit 4 (yellow in table below), second digit 7 (violet), followed by 2 (red) zeros: 4,700 ohms. Gold signifies that the tolerance is ±5%, so the real resistance could lie anywhere between 4,465 and 4,935 ohms.

PROCEDURE

Step: 1

Hold one of the given resistors in such a way that closest bands come in left side.

Step: 2

Read and record the value of resistor in column ‘A’ of table-1 by observing colors from left side to right side. Note:

The colors of first bands I & II indicate significant figures in ohms, while the color of third band indicates the multiplying factor.

Step: 3

Read and record the tolerance value in column ‘B’ of table-1 by observing the fourth band.

CONNECTION OF DMM

USING MULTIMETER AS OHM METER

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Fig.2.1 Measurement of resistance using Multimeter as Ohm meter

Tabulation

S.I

No

Calculated Resistance

Measured Resistance in Ohm

DifferencesResistance in Ohm

Tolerance in %

NOTE:

The color of fourth band indicates the percentage tolerance. Incase if band four is not there (that is no color) the tolerance is assumed to be + 20 %.

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Step: 4

Measure the resistance value with the help of Digital Multi Meter (DMM), and record the value in column ‘C’ of table-1.

Step: 5

Calculate and record the difference of calculated and measured resistance values in column ‘D’of tale-1.

Step: 6

Take another resistor and repeat the procedure from step-1 to step-5.

PRECAUTIONS

Observe the colors of the bands carefully.

Read the values of color code attentively.

DIGITAL MULTIMETER

A multimeter, also known as a volt/ohm meter or VOM, is an electronic measuring instrument that combines several measurement functions in one unit. A typical multimeter may include features such as the ability to measure voltage, current and resistance. Multimeters may use analog or digital circuits -analog multimeters and digital multimeters. (often abbreviated DMM or DVOM).

TO CALCULATE THE VALUE OF CAPACITOR

ELECTROLYTIC CAPACITORS

It is easy to find the value of electrolytic capacitors because they are clearly printed with their capacitance, voltage rating and polarity.

BY USING NUMERALS:

Unpolarised capacitors (small values up to 1microfarad).

Small values capacitors are unpolarised.So it can be connected in any way. They have high voltage rating.

Many small value capacitors are printed. For e.g.: 0.1 means 0.1 microfarad.

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Fig.2.2 Capacitors

70

A number code is often used on small capacitors where printing is difficult. The first number is the first digit, the second number is the second digit and the third number is the number of zeros to give the capacitance in pF.Ignore any letters, they just indicate the tolerance and voltage rating.

RESULT

Thus the resistors and capacitor values are determined and verified.

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Figure 3.1 Block diagram of oscilloscope

72

EX NO:3DATE:

FAULT IDENTIFICATION AND TROUBLE SHOOTING OF CRO, FUNCTION GENERATOR AND POWER SUPPLY UNITS

AIM

To Study the fault identification and trouble shooting of CRO, function generator and power Supply units.

THEORY

CRO and function generators theory are discussed below.

1. CRO

C.R.O. (Cathode Ray Oscilloscope) is the instrument which is used to observe signal waveforms. Signals are displayed in time domain i.e. variation in amplitude of the signal with respect to time is plotted on the CRO screen. X-axis represents time and Y-axis represents amplitude. It is used to measure amplitude, frequency and phase of the waveforms. It is also used to observe shape of the waveform. C.R.O. is useful for troubleshooting purpose.

It helps us to find out gain of amplifier, test oscillator circuits. We can measure amplitude and frequency of the waveforms at the different test points in our circuit. Thus, it helps us for fault finding procedure. In dual channel C.R.O. X-Y mode is an available mode which is used to create Lissajous patterns.

Latest digital storage oscilloscope display voltage and frequency directly on the LCD and does not require any calculations. It can also store waveform.

2. FUNCTION GENERATOR

A function generator is a device that can produce various patterns of voltage at a variety of frequencies and amplitudes. It is used to test the response of circuits to common input signals. The electrical leads from the device are attached to the ground and signal input terminals of the device under test.

3. FEATURES AND CONTROLS

Most function generators allow the user to choose the shape of the output from a small number of options.

Square wave - The signal goes directly from high to low voltage. Sine wave - The signal curves like a sinusoid from high to low voltage.

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Triangle wave - The signal goes from high to low voltage at a fixed rate.

The amplitude control on a function generator varies the voltage difference between the high and low voltage of the output signal. The direct current (DC) offset control on a function generator varies the average voltage of a signal relative to the ground. The frequency control of a function generator controls the rate at which output signal oscillates. On some function generators, the frequency control is a combination of different controls. One set of controls chooses the broad frequency range (order of magnitude) and the other selects the precise frequency. This allows the function generator to handle the enormous variation in frequency scale needed for signals. The duty cycle of a signal refers to the ratio of high voltage to low voltage time in a square wave signal.

PROCEDURE

The oscilloscope is an excellent tool for providing clues to faults within itself. In addition to the CRT display, the calibrator signals and the front panel indicators provide sufficient information to isolate the problem.

The following list provides a logical sequence to follow while trouble shooting in CRO, function generator and power supply unit.

Step: 1

Check control settings.

Step: 2

Check associated equipment.

Step: 3

Make a thorough visual check of the instrument.

Step: 4

Isolate trouble to a block level.

Step: 5

Check voltages and waveforms.

Step: 6

Check individual components.

Observing the effects of different multi-function switch positions can do much to identify a problem.

RESULT

Thus the method of using CRO, function generator, power supply units with fault identification and troubleshooting were studied.

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AND GATE : IC7408

LOGICAL SYMBOL TRUTH TABLE

Figure 5.1

PIN CONFIGURATION OF 7408

Figure 5.3

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INPUTS OUTPUT

A B X

0 0 0

0 1 0

1 0 0

1 1 1

AX

B

EX NO:4 VERIFICATION OF LOGIC GATESDATE:

AIMTo verify the various basic Digital IC’s which include AND, OR, EXOR, NOR,

NAND, EXNOR, NOT.

APPARATUS REQUIRED

S.NO APPARATUS TYPE/RANGE QUANTITY1 IC 7408,7432,7486,7402,7400

74266,7404Each 1

2 IC Trainer Kit 13 Patch Cords As Required

THEORYThe gate is digital circuit with one or more input voltages but only one output voltage.

By connecting the different gates in different ways, we can build circuits that can perform

arithmetic and other functions associated with the human brain because they simulate mental

processes. The operation of a logic gates can be easily understood with the help of a truth

table. A truth table is a table that shows all the input-output possibilities of a logic Circuit ie,

the truth table indicates the outputs for different possibilities of the inputs.

BASIC GATES

AND GATEThe IC for AND gate is 7408. The pin configuration is given in Fig 5.3 the

Logical diagram and the truth table is given in Fig 5.1 and 5.2 Respectively.

OR GATEThe IC for OR gate is 7432. The pin configuration is given in Fig 5.6 the

Logical diagram and the truth table is given in Fig 5.4 and 5.5 Respectively.

NAND GATEThe IC for NAND gate is 7400. The pin configuration is given in Fig 5.9 the

Logical diagram and the truth table is given in Fig 5.7 and 5.8 Respectively.

OR GATE :IC 7432

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LOGIC DIAGRAM TRUTH TABLE

Figure 5.4

PIN DIAGRAM OF 7432

Figure 5.5

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INPUTS OUTPUT

A B X

0 0 0

0 1 1

1 0 1

1 1 1

AB

X

EXNOR GATEThe IC for NAND gate is 74266. The pin configuration is given in Fig 5.12

the Logical diagram and the truth table is given in Fig 5.10 and 5.11 Respectively.

NOT GATEThe IC for NAND gate is 7402. The pin configuration is given in Fig 5.15 the

Logical diagram and the truth table is given in Fig 5.13 and 5.14 Respectively.

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NAND GATE: IC 7400

LOGICAL SYMBOL TRUTH TABLE

Figure 5.6

PIN CONFIGURATION OF 7400

Figure 5.7

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INPUTS OUTPUT

A B X

0 0 1

0 1 1

1 0 1

1 1 0

A

BX

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EXNOR GATE: IC 74266

LOGICAL SYMBOL TRUTH TABLE

Figure 5.9

Figure 5.10

PIN CONFIGURATION OF 74266

Figure 5.11

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INPUTS OUTPUT

A B X

0 0 1

0 1 0

1 0 0

1 1 1

AB

X

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NOT GATE:

LOGICAL SYMBOL TRUTH TABLE

Input Output

X Y

0 1

1 0

Figure 5.13

Figure 5.14

PIN CONFIGURATION OF IC 7404:

Figure 5.15

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YX

RESULT Thus the various logic gates and their functions are verified successfully.

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CATHODE RAY OSCILLOSCOPE:

Figure 6.1

Figure 6.2

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EX.NO: 5 STUDY OF CRODATE:

AIM: To study the operation and various functions of CRO.

APPARATUS REQUIRED:

S.No Apparatus Range Quantity1. CRO 5MHz 12. Multimeter 13 Connecting Wires As required

THEORY:

The cathode-ray oscilloscope (CRO) is a common laboratory instrument that provides accurate time and amplitude measurements of voltage signals over a wide range of frequencies. Its reliability, stability, and ease of operation make it suitable as a general purpose laboratory instrument. The heart of the CRO is a cathode-ray tube shown schematically in Fig. 6.1

The cathode ray is a beam of electrons which are emitted by the heated cathode (negative electrode) and accelerated toward the fluorescent screen. The assembly of the cathode, intensity grid, focus grid, and accelerating anode (positive electrode) is called an electron gun. Its purpose is to generate the electron beam and control its intensity and focus.

Between the electron gun and the fluorescent screen are two pair of metal plates - one oriented to provide horizontal deflection of the beam and one pair oriented at give vertical deflection to the beam. These plates are thus referred to as the horizontal and vertical deflection plates.

The combination of these two deflections allows the beam to reach any portion of the fluorescent screen. Wherever the electron beam hits the screen, the phosphor is excited and light is emitted from that point. This conversion of electron energy into light allows us to write with points or lines of light on an otherwise darkened screen.

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BLOCK DIAGRAM

Figure 6.3

CONNECTION DIAGRAM

Figure 6.4

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CRO CONTROLS

Power and Scale Illumination: Turns instrument on and controls illumination of the cathode ray.

Focus: Focus the spot or trace on the screen.

Intensity: Regulates the brightness of the spot or trace.

Position: Controls vertical positioning of oscilloscope display. Sensitivity: Selects the sensitivity of the vertical amplifier in calibrated steps.

Variable Sensitivity: Provides a continuous range of sensitivities between the calibrated steps.

AC-DC-GND: Selects desired coupling (ac or dc) for incoming signal applied to vertical amplifier, or grounds the amplifier input.

CONNECTIONS FOR THE OSCILLOSCOPE

Vertical Input: A pair of jacks for connecting the signal under study to the Y (or vertical) amplifier. The lower jack is grounded to the case.

Horizontal Input: A pair of jacks for connecting an external signal to the horizontal amplifier. The lower terminal is grounded to the case of the oscilloscope.

External Trigger Input: Input connector for external trigger signal.

Cal. Out: Provides amplitude calibrated square waves of 25 and 500 millivolts for use in calibrating the gain of the amplifiers.

PROCEDURE

Measurement of Voltage: Consider the circuit in Fig.6. 4(a). The signal generator is used to produce a 1000 hertz sine wave. The AC voltmeter and the leads to the vertical input of the oscilloscope are connected across the generator's output.

STEP-1 By adjusting the Horizontal Sweep time/cm and trigger, a steady trace of the sine wave may be displayed on the screen.STEP-2 The trace represents a plot of voltage vs. time, where the vertical deflection of the trace about the line of symmetry CD is proportional to the magnitude of the voltage at any instant of time.

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Frequency Measurement:

When the horizontal sweep voltage is applied, voltage measurements can still be taken from the vertical deflection. Moreover, the signal is displayed as a function of time. If the time base (i.e. sweep) is calibrated, such measurements as pulse duration or signal period can be made.

STEP-1 Frequencies can then be determined as reciprocal of the periods. Set the oscillator to 1000 Hz. Display the signal on the CRO and measure the period of the oscillations.

STEP-2 Use the horizontal distance between two points such as C to D in Fig.6. 4b.

STEP-3 Set the horizontal gain so that only one complete wave form is displayed.

STEP-4 Then reset the horizontal until 5 waves are seen.. Measure the distance (and hence time) for 5 complete cycles and calculate the frequency from this measurement. Compare you result with the value determined above.

STEP-5 Repeat your measurements for other frequencies of 150 Hz, 5 kHz, 50 kHz as set on the signal generator.

RESULT Thus the CRO was studied and the Electrical Parameters such as Voltage and Frequencies were measured using the CRO.

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EX NO: 6 DATE:

SOLDERING PRACTICE & DESOLDERING

AIM:To practice soldering and to verify the continuity of the soldering using multimeter.

APPARATUS REQUIREDS.NO APPARATUS TYPE/RANGE QUANITY

1 Solder iron 25W 12 Flux 1 box3 Solder wire 1 M4 Resistors As applicable 25 PCB Board 16 Sand paper 17 Brush 1

THEORYSoldering is the process of connecting the parts by ensuring metal continuity.

The Process consists of:

1. Removal of oxide film from the metal with the help of sand paper or melting of Flux.

2. Melting of solder makes the impurities and flux float on its surface.

3. Solder dissolves some metal in the connection.

4. The flux and impurities are removed with a brush.

SOLDERING IRON

An iron should be between 25 to 35 W.The iron temperature should not

exceed 300 C to400 C and contact time not more than 5 seconds.

PROCEDURE- SOLDERING

1. The component lead wire is rubbed with sand

2. Paper, brushed with liquid flux and dry with paper.

3. General purpose PCB: general PCB should be cleaned (remove the oxide layer from

the metal) with the help of sandpaper.

4. Touch the tip of iron to most of the element of the joints.

5. Place the iron at 45 angles.

6. Place the Wire near the iron and move it over the joint.

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7. The molten metal should cover all the elements of the joint.

8. Remove solders wire.

9. Remove iron.

DESOLDERING

The desoldering is the process of taking back the components from the

soldered boards. This is useful in case of a mistaked soldering .

PROCEDURE-DESOLDERING

1. Touch the tip of iron to most of the element of the joints.

2. Place the iron at 45 angles.

3. Gently pull the soldered components out of the board using a nose plier.

RESULT

Thus the Given components were soldered and desoldered successfully.

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Figure 1.1. Computer

Figure .1.2. Motherboard

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1.Monitor2.Motherboard3.Processor4.RAM5.Slots6.SMPS7.CD/DVD Writer8.Floppy disk9.Keyboard10.Mouse

EX NO: 1 DATE 1 a) STUDY OF PC HARDWARE

AIM

To study the Personal computer hardware components

THEORY

COMPUTER HARDWAREBasic components in a computer system are central processing unit

(CPU), memory, the input device and output device.

SYSTEM COMPONENTSComponent needed to assemble a basic modern PC system.1. Motherboard2. Processor3. Memory (Primary)4. Hard disk5. CD-ROM6. Floppy Drive7. Keyboard8. Mouse9. Monitor10. Power Supply11. Cabinet

1.MOTHERBOARD Motherboard is the important component of the computer as everything else is

connected to it. And it controls everything in the system. Motherboard is available in several different shapes. Motherboard usually contains the following individual components.

(i). Processor slot(ii). Processor voltage regulators(iii). Motherboard chipset(iv). Level 2 cache(v). Memory SIMM or DIMM sockets(vi). Bus slots(vii). ROM BIOS(viii). Clock / CMOS battery(ix). Super I/O chips

2.PROCESSOR

The processor is often thought as the engine of the computer. Then the processor reads the commands from the memory and then executes them. The processor is one of the most expensive parts of the computers and is also one of the smallest parts.

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Figure 1.3 .Shows Processor Chips

Figure1.4 .Shows Memory Chips

Figure1.5 .Hard Disk Drive

Figure1.6. CDROM Drive

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3.PRIMARY MEMORY

Memory: Is used to hold programs and data during execution.Primary memory is often called as RAM (Random Access Memory). It holds all the programs and data the processor is using at a given time. RAM is volatile because its contents are erased when power is switched off.The other type of system memory is ROM (Read only Memory) which is permanent because it contents are not erased even when power is switched off. It is usually used to load an operating system.

4.HARD DISK DRIVE

A hard drive consists of spinning platters made up of aluminium or ceramic that is coated with magnetic media. The platters come in various sizes. The hard drive with many different storage capacities can be created depending upon the density, size and number of platters.This is also called as Secondary memory. There can be several programs in the system, which cannot be stored in RAM, so we need a very huge non-volatile memory, which can be used for storing all the programs, and data when the system is not in use are called as Hard disks.

5.CD-ROM DRIVE

CD-ROM stands for compact disk read only memory. It consists of small disks similar to the gramophone records to hold digital information. As the name applies they are read only medium. With the advancement in technology writable CD’s are also available.

6.FLOPPY DISK DRIVE

Floppy disks are the slowest and the smallest form of secondary storage. They provide a simple way to carry information from one place to another, and backup small amount of files. In modern days floppy drive component is not as important as it was years ago. All PC’s made in the last 10 years use a standard 3 ½ inch, 1.44 MB capacity floppy drive.

7.KEYBOARD

The keyboard is the main input device for most computers. It is used to input text or enter commands into the PC. Nowadays keyboards with additional features are available like multimedia keyboard, wireless keyboard.

8.MOUSE

With the invention of graphical user interface mouse is used to input information into the computer. Users simply point and click to enter information. The main advantage of

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mouse over keyboard is simplicity. And there are many operations that are much easier to perform with a mouse then a keyboard.

Figure 1.7 .Shows Floppy Disk Drive

Figure 1.8. Shows Keyboard

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Figure1.9 .Shows Mouse

9.MONITOR

The monitor is the specialized high-resolution screen similar to a television. The video card sends the contents of its video memory to the monitor at a rate of 60 or more time per second. The actual display screen is made up or red, green and blue dots that are illuminated by electron beam from behind. The video card DAC chip controls the movement of the electron beam, which then controls what dots are turned on and how bright they are. This then determines the picture you see on the screen.

10.POWER SUPPLY

SMPS (Switch Mode Power Supply): The power supply supplies power to every single part in the PC. The main function of the power supply is to convert the 230 V AC into 3.3 V, 5 V and 12 V DC power that the system requires for the operations.

In addition to supplying power to run the system, the power supply also ensures that the system does not run unless the power supplied is sufficient to operate the system properly. The power supply completes internal checks and tests before allowing the system to start. If the tests are successful, the power supply sends a special signal to the motherboard called Power Good. If this signal is not present continuously, the computer does not run. Therefore, when the AC voltage dips and the power supply becomes stressed or overheated, the Power Good signal goes down and forces a system reset or complete shutdown.

11.CABIN

The box or outer shell that houses most of the computers. The cabinet actually performs several important functions for your PC including protection to the system components, directing cooling airflow, and allowing installation of and access to the system components. The cabinet often includes a matching power supply and must also be designed with shape of the motherboard and other system components in mind.

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.

Figure1.10 Shows Monitor

Figure1.11.Shows Power Supply (SMPS)

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Figure 1.12 .Shows Cabinet

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RESULT

Thus the Personal computer hardware components is studied.

Figure 1.13 Shows CPU Module

Figure1.14. Slide the computer cover back and then up while removing it from the chassis frame.

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EX NO: 1 DATE:

B) ASSEMBLING THE COMPUTER SYSTEM

AIM

To study and assemble the computer system.

APPRATUS REQUIRED

1. Head (cross-shaped) screwdriver2. Needle nose pliers3. Anti-static Wrist Strap4. A large level working space

THEORY

Assembling a PC from scratch is quite a bit different than disassembling and reassembling a computer that’s being repaired. It’s pretty easy to remove a component from a PC and then reinstall it. Building a computer from a pile of components and screws… That’s not so easy. In this exercise, you’ll learn a little about the PC case and how to install computer components like the main board, processor, memory, power supply, interface boards, and drives. You’ll also learn to recognize the correct screws and fasteners used during PC assembly. Even though the computer may work when you’re finished, it’s critical that you follow the assembly instructions precisely. Only then is the assembly considered complete and correct.

PROCEDURE

Install the Power SupplyStep 1Remove the screws that hold the side panels in place.Remove the side panels.Step 2Align the screw holes in the power supply with the screw holes in the case.Secure the power supply to the case using the proper screws.Step 3If the power supply has a voltage selection switch, set this switch to match the voltage in your area.Install the Motherboard

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In this lab, you will install a CPU, a heat sink/fan assembly, and a RAM module on the motherboard. Place the motherboard, CPU, RAM, and the heat sink/fan assembly on the antistatic mat.

Figure1.15. Shows Mother Board

Figure1.16. Applying thermal compound to processor re1.17. Heat sink registration pins in the

Processor board

Figure1.18.ZIF sockets Figure1.19. heat sink and processor interface

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Step 2 Processor InstallationPut on your antistatic wrist strap and attach the grounding cable to the antistatic mat.Locate pin 1 on the CPU. Locate pin 1 on the socket.

Note:The CPU may be damaged if it is installed incorrectly.Align pin 1 on the CPU with pin 1 on the socket.Place the CPU into the CPU socket.Close the CPU load plate and secure it in place by closing the load lever and moving it under the load lever retention tab.

Step 3Apply a small amount of thermal compound to the CPU, and then spread it evenly.

Note:Thermal compound is necessary only when not factory applied on the heat sink assembly. Follow all instructions provided by the manufacturer for specific application details.

Step 4Align the heat sink/fan assembly retainers with the holes on the motherboard around the CPU socket.Place the heat sink/fan assembly onto the CPU and the retainers through the holes on the motherboard.Tighten the heat sink/fan assembly retainers to secure it.Plug the fan connector into the motherboard. Refer to the motherboard manual to determine which set of fan header pins to use. Step 5Locate the RAM slots on the motherboard.Align the notch (es) on the bottom edge of the RAM module to the notches in the slot.Press down until the side tabs secure the RAM module.Ensure that none of the RAM module contacts are visible. Reseat the RAM module if necessary.Check the latches to verify that the RAM module is secure.Install any additional RAM modules using the same procedures.Step 6Install the motherboard standoffs.Align the connectors on the back of the motherboard with the openings in the back of the computer case.Place the motherboard into the case and align the holes for the screws and the standoffs. You may need to adjust the motherboard to line up the holes for the screws.Attach the motherboard to the case using the appropriate screws.Step 7Connect the wires from the case link lights and buttons to the motherboard connectors.

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Figure1.20. Installing a memory module . Figure1.21. A completely populated on main board

Figure1.22. Remove and reposition the 5.25” EMI shield with a common

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Figure1.23. Slide the drives through the front panel Figure1.24.Slide the hard disk drive from inside

Install the DrivesStep 1Align the hard disk drive with the 3.5-inch drive bay.Slide the hard disk drive into the bay from the inside of the case until the screw holes line up with the holes in the 3.5-inch drive bay.Secure the hard disk drive to the case using the proper screws.Step 2Note:Remove the 5.25-inch cover from one of the 5.25-inch external drive bays if necessary.Align the optical drive with the 5.25-inch drive bay.Insert the optical drive into the drive bay from the front of the case until the screw holes line up with the holes in the 5.25-inch drive bay and the front of the optical drive is flush with the front of the case.Secure the optical drive to the case using the proper screws.Step 3Note:Remove the 3.5-inch cover from one of the 3.5-inch external drive bays if necessary.Align the floppy drive with the 3.5-inch drive bay.Insert the floppy drive into the drive bay from the front of the case until the screw holes line up with the holes in the 3.5-inch drive bay and the front of the floppy drive is flush with the front of the case. Secure the floppy drive to the case using the proper screws.Install Adapter CardsIn this lab, you will install a NIC, a wireless NIC, and a video adapter card.Step 1What type of expansion slot is compatible with the NIC?PCI or PCIeLocate a compatible expansion slot for the NIC on the motherboard.Remove the slot cover from the back of the case, if necessary.Align the NIC to the expansion slot.Press down gently on the NIC until the card is fully seated.Secure the NIC by attaching the PC mounting bracket to the case with a screw.Step 2What type of expansion slot is compatible with the wireless NIC?PCI or PCIeLocate a compatible expansion slot for the wireless NIC on the motherboard.Remove the slot cover from the back of the case, if necessary.Align the wireless NIC to the expansion slot.Press down gently on the wireless NIC until the card is fully seated.Secure the wireless NIC by attaching the PC mounting bracket to the case with a screw.Step 3What type of expansion slot is compatible with the video adapter card?PCI, AGP, or PCIeLocate a compatible expansion slot for the video adapter card on the motherboard.Remove the slot cover from the back of the case, if necessary.Align the video adapter card to the expansion slot.

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Press down gently on the video adapter card until the card is fully seated.Secure the video adapter card by attaching the PC mounting bracket to the case with a screw.

Figure 1.25.3 Front panel header connections Figure1.26. 34-Pin floppy drive data cable.

Figure1.27.-Pin IDE cable Figure1.28.The CDROM audio cable

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Figure 1.29.8Pin ATX power connector from the power supply to the main board

Figure1.30.ThePentium 4 main board additional 12 volt power connection

Install Internal CablesStep 1Align the motherboard power supply connector to the socket on the motherboard.Gently press down on the connector until the clip clicks into place.Step 2Note:This step is necessary only if your computer has an auxiliary power connector.Align the auxiliary power connector to the auxiliary power socket on the motherboard.Gently press down on the connector until the clip clicks into place.Step 3Plug a power connector into the hard disk drive, optical drive, and floppy drive. Ensure that the floppy drive power connector is inserted right side up.Step 4Note:This step is necessary only if your computer has a fan power connector.Connect the fan power connector into the appropriate fan header on the motherboard.Step 5Note:Pin 1 on a PATA cable must align with Pin 1 on the motherboard connector and the hard disk drive connector.Align and plug the hard disk drive data cable into the motherboard connector.Align and plug the other end of the hard disk drive data cable into the hard disk drive connector.Step 6Note:Pin 1 on a PATA cable must align with Pin 1 on the motherboard connector and the optical drive connector.Align and plug the optical drive data cable into the motherboard connector.Align and plug the other end of the optical drive data cable into the optical drive connector. Step 7Align and plug the floppy drive data cable into the motherboard connector.Align and plug the other end of the floppy drive data cable into the floppy drive connector.

Complete the Computer Assembly

Step 1Attach the side panels to the computer case.Secure the side panels to the computer using the panel screws.Step 2Attach the monitor cable to the video port.Secure the cable by tightening the screws on the connector.Step 3Plug the keyboard cable into the PS/2 keyboard port.

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Step 4Plug the mouse cable into the PS/2 mouse port.

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Figure 1.31.0Pentium 4 main board also requires an auxiliary power connector for 3.3V and 5V DC power.

Figure1.32. Insert the IDE connector into the Primary IDE port on the main board

Figure1.33.Plug the remaining connector on the Primary IDE cable into the CDROM Drive

Step 5Plug the hub USB cable into any USB port.Step 6Plug the printer USB cable into a USB port in the hub.Step 7Plug the Ethernet cable into the Ethernet port.Step 8Connect the wireless antenna to the antenna connector.Step 9Plug the power cable into the power socket of the power supply.

Boot the Computer

Step 1Plug the power supply cable into an AC wall outlet.Turn on the computer.Note:If the computer beeps more than once, or if the power does not come on, notify your instructor.Step 2During POST, press the BIOS setup key or key combination.The BIOS setup program screen will appear.Step 3Navigate through each screen to find the boot order sequence.Step 4Ensure that the first boot order device is the optical drive.Ensure that the second boot order device is the hard disk drive.Step 5Navigate through each screen to find the power management setup screen, or ACPI screen.Step 6Navigate through each screen to find the PnP settings.Step 7Save the new BIOS settings and exit the BIOS setup program.Step 8The computer will restart. Note: An error message stating that an OS cannot be found (or a similar error) will appear on the screen after the computer boots. An operating system must now be installed to remove this error. It is safe to turn off the computer at this time.An operating system can be installed at this time.RESULT

Thus the computer assembling has been studied.

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Press "S" to specify the driver for the controller card.

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EX NO: 1 DATE 2 a) FORMATTING AND PARTITIONING HDD

AIM

To Study the Formatting and partitioning of Hard disk.

Procedure:

Windows 2000/XP hard drive setup during installation

To begin the installation of Windows 2000 / XP, you will need to insert the bootable Windows CD into the CD drive. If you are installing from floppies, insert the first floppy into drive A: Turn the system on.One of the first things you will see during the installation process is “Press F6 if you need to install additional drivers. The message only appears for 6 seconds before the installation continues. You will need to press F6 to load additional drivers if you are using a SCSI controller card, a SATA controller card, or a RAID controller card that is not natively supported by Windows. Check with your controller card manufacturer for the latest drivers.

*Wording on screenshots may differ slightly between Windows 2000 and XP.

You are now presented with 3 options. For the purpose of this guide, press Enter.

Before you can install the operating system you must press F8 and agree to the license agreement.In order to install an operating system, you will need a partition on which to install. If a partition does not already exist, you must create one. To do this, highlight the "Unpartitioned Space" and press "C", for Create.

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Enter the capacity you want for the new partition and press Enter. If you want to use the entire space of the drive, press Enter without making any changes.

You will now be brought back to the screen which previously showed the "Unpartitioned Space" taking up the whole drive. Now, it shows it as Partition1 [New <RAW>] (this means it has not yet been formatted). To continue with the installation process and format the drive, highlight the new partition and press Enter

You will be given format options for the partition: NTFS, NTFS (Quick), FAT, and FAT (Quick). Only Windows XP gives the Quick format options. If the partition is larger than 32GB's, you must choose NTFS.

*WARNING* Formatting will delete all data from the drive

The installation will now begin formatting the drive to your specifications.Depending on the size of the partition, this could take anywhere from 2 minutes to over an hour to format.*Note: For drives larger than 137GB you will need Service Pack 3 for Windows 2000, Service Pack 1 for Windows XP, or a controller driver that supports 48 bit addressing to format the full capacity during installation. Once the OS is installed, you may update the OS to the latest Service Pack and then partition the remainder of the drive through Disk Management.

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EX NO: 2 DATE: B) CONFIGURING CMOS-SETUP

AIM

To study the configuration of CMOS-SETUP.

THEORY

Tech Note: The system’s BIOS ROM has a built-in setup program that allows the user to modify the basic system configuration. This information is stored in the non-volatile memory portion of the CMOS chip. Since this is non-volatile RAM, it can retain the setup information even when the power is turned off. The CMOS battery keeps track of the system’s date and time. In most computers, when you turn on or reboot the system, you press the Delete key to enter the BIOS setup program. Your system may have a different key sequence to bring up the BIOS setup utility. Watch the boot screen… There’s usually a hint there.

The primary BIOS Setup screen that appears is a list of the menus and functions available in the setup program. The user would select the desired item and press enter to make changes. Operating commands are located on the screen someplace. When a field is highlighted, on-line help information is displayed to give you an idea what you should do. This is important! Configuring the system BIOS is a science in and of itself. Tweaking the BIOS is an excellent way to speed up the boot process, protect the system, enable hidden features, and even speed-up the processor. However, messing around with the system settings can also disable your computer and even destroy the processor if you’re not careful. In this portion of the exercise you’ll learn some of the basic settings in the PC BIOS.

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Standard CMOS Setup Date/Time Set the date and time. Do not skip this function as all of your timed events such as power management, saving files, etc. are based on this timer. Hard Disk Setup (Primary/Secondary; Master/Slave) This category identifies up to four IDE hard disk drives that have been installed in the computer. This section does not show information on other IDE devices such as CD-ROM drives or other hard drive types such as SCSI drives. Type (Auto/User/None): Use the fields under the Type column to determine the method you will use to configure the IDE devices. If you choose Auto, BIOS will automatically detect and make optimal settings for most IDE hard drives. The main board manufacturer recommends that you choose Auto for all drives. Floppy Disk Drives

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Choose the memory capacity and disk size that corresponds with that of your floppy disk drive(s).

BIOS Features Setup

Boot Sequence

This option sets the sequence of drives BIOS attempts to boot from after POST completes. BIOS will search these drives for an operating system.

PNP/PCI Configuration

PNP OS Installed

If you want to install a PNP compatible OS (such as Windows 95, 98, 2000, XP) set to Yes.

Supervisor Password

There are four different variables that control password settings. The first two are located under the Security Option function in BIOS Features Setup Menu. When the Security Option function is set to Setup, a password is required to enter BIOS and change BIOS settings. When the Security Option function is set to System, a password is required to enter both BIOS and the computer's operating system found on the boot drive.

The third and fourth variables are user password and supervisor password selected in BIOS. The main purpose of separating user and supervisor is to allow only the supervisor to have control over the settings in BIOS. The user, on the other hand, is only allowed to access the computer's operating system and change the user password in BIOS. Note that when there is no supervisor password set, the user password controls access to all BIOS settings. Not necessarily a good idea.

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Integrated Peripherals

On-Chip USB

Some main boards require you enable the USB ports in the BIOS before they can be used. You’ll need to do this regardless of the operating systems settings.

Load Setup Defaults

Load Setup Defaults loads the default system values directly from the CMOS Setup Utility menu. These are the factory default settings and are a good place to start if you’ve made a mess of things while tweaking the BIOS. If the stored record created by the setup program becomes corrupted and therefore unusable, these defaults will be loaded automatically when you turn on the computer.

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PROCEDURE

Step 1: Study the Sample BIOS Setup Guide for detailed instructions. Step 2: Reboot the PC and enter the BIOS Setup Utility. Step 3: Set the PC for the Current Date and Time. Step 4: Set all the Hard Disk types to Auto. Step 5: Set Floppy Drive A to 1.44 3.5 in and Floppy Drive B to None. Step 6: Set the Boot Sequence to A, CDROM, C Step 7: Set the BIOS for a Plug and Play operating system. Step 8: Set the Supervisor Password to “password” Step 9: If applicable, Enable the On-Chip USB

Step 10: ( ) Supervisor Check Step 11: Reset the BIOS by loading the setup defaults. Step 12: Save the BIOS settings and exit the CMOS Setup Utility. Step 13: Reboot the computer and enter the BIOS Setup Utility using the supervisor

password. Step 14: Refer to the main board’s user manual to reset the passwords with the jumpers

or switches on the main board. Step 15: Reboot the PC to verify the password to the BIOS Setup Utility has been reset

RESULT:

Thus the configuration of CMOS-SETUP is studied.

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EX NO: 2 DATE 2C) INSTALLATION OF OS

AIM

To study the Installation of operating system.

THEORY

Operating system: It is a software which allows the users to use computers.Without OS a computer is a mere machine, which is incapable of performing anywork.

Ex : DOS, Windows 9x, Linux, OS/2 , Solaris etc

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Windows 98 Installation

Need for installing windows 98.1. Windows 98 CD.2. Computer with CD-ROM Access.

Configuring your BIOS for the Install:To find out how to access the BIOS please refer to your motherboard manual or the

manufacturer of your computer. (The system bios can usually be entered on boot, usually by pressing the F1, F2, F8, F10 or DEL key. Make sure you save the settings before exiting. If you are unsure or don’t want to enter the BIOS then just test the computer by putting the CD-ROM in the drive and rebooting the computer.

PROCEDUREStarting The Setup

STEP1: Insert CD and restart PC.STEP2: Once the Windows 98 Setup Menu comes up choose option 2 (Boot from CD-ROM)STEP3: Then the Windows 98 Start-up Menu will come up. Select Option 1. (Start Windows

98Setup from CD-ROM)STEP4: Now your computer will install some drivers so please wait a few moments.STEP5: Now a blue setup screen will come up. Press enter.STEP6: Setup then wants to do some system tests. Just press enter.STEP7: Scandisk will now run, please wait.STEP8: After Scandisk completes Windows will copy a few important files for setup.STEP9: Now the graphical Windows 98 Setup Screen will come up.

STEP10: Click continue and wait for the setup wizard to complete.STEP11: Now it will ask you in which directory to install Windows to. The default directory is

just fine so click next.STEP12: Setup will now prepare the directory, please wait.STEP13: Setup will now check for installed components and disk space, please wait.STEP14: Setup will now prompt you what type of install. Choose typical if you have a desktop

computer or portable if it is a laptop.STEP15: Windows will prompt you to install components, just choose continue.STEP16: If a network card is detected a network information screen will appear. Type in the

required information and click next

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STEP17: Select your country settings, United States should be chosen by default.STEP18: Now finally the main part of Setup is here. Setup will start copying files. This will

take a pretty long time, be patient.STEP19: Once setup is done copying files Windows will restart automatically.STEP20: The Windows 98 Start-up Menu will appear. Select option 1 (Boot from Hard Disk)STEP21: The Windows 98 booting screen will appear!STEP22: Now Windows will prompt you for user information, enter it and click continue.STEP23: Now the License Agreement. Read and if you agree click on “I accept the

Agreement” and click next. If you select “”I don’t accept the Agreement “then setupwill end.

STEP24: Now input your product key computer. Click next to continue.STEP25: Next click on Finish.STEP26: Setup will now finalize the hardware and install settings.

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STEP27: Setup will now install plug and play devices.STEP28: Your computer will restart automatically.STEP29: The Windows 98 Start-up Menu will appear. Select option 1 (Boot from Hard Disk)STEP30: Windows will start booting for the second time.STEP31: Setup will continue installing hardware.STEP32: Now setup will prompt you to enter in your time, date, and time zone. Once selected

click on apply and then ok.STEP33: Windows will continue to setup Windows items.STEP34: The computer will restart automatically once again.STEP35: The Windows 98 Start-up Menu will appear. Select option 1 (Boot from Hard Disk)STEP36: Windows will boot for the third time.STEP37: Windows will update system settings.STEP38: Now finally you have reached the Windows Desktop!STEP39: You also may need to install your hardware drivers. If everything is working properly

then you shouldn’t worry about them.

RESULT:

Thus the Installation of operating system is studied.

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