LABORATORY MANUAL

COURSE CODE: ECE 130

COURSE TITLE: ELECTRICA

L AND ELECTRONICS WORKSHOP

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LIST OF PRACTICALS

S. No.

List of Jobs Page no

Part I1 Acquaintance with the tools and equipments used for electrical

and electronics workshop.

Electrical safety measures.

Making of extension board containing two 5A and one 15A plug-points.

3-5

2 Wiring of different lamp control, stair casing circuits. Assembly and wiring of fluorescent tube light. Connection of table and ceiling fans with regulators.

6-9

3 To make a single phase main distribution board with five outgoing circuits for light and fan load including main switch and fuses (only internal connections).

Wiring and testing of alarm and indicating relays, indicating lights etc.

11-12

4 Coil winding for small transformers or alarm bell. Assembling small transformer cores from the given lamination plates.

13-15

5 Soldering electronic elements with the necessary switches micro-switches and extension terminals.

16-18

6 Dismantling, repairing, assembling and testing of domestic appliance like electric iron, ceiling fan, Table Fan, regulators, alarm bell.

19-20

Part II(after MTE)7 Armature winding of table fan. Armature winding of ceiling fan. 21-228 Dismantling and assembling of desktop CPU. 23-309 a) PCB schematic of a full wave rectifier.

b) Transferring of image on Clad Board.c) Etching, drilling and solder maskingd) Mounting of components and testing.

31-34

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Practical no 1Electrical Safety Occupational electrocutions continue to be a serious problem throughout the campus. If you are not a qualified electrician you should not be servicing any electrical equipment or doing wiring and working the power panel is prohibited. If you are a qualified individual, always be aware of your work environment and exercise safe working procedures.

Basic Electrical Safety Guidelines

1. Keep your work area clean and orderly. This reduces the chance of accidents and prevents the accumulation of combustibles as well as flammable materials in the workplace.

2. Never work around a source of electricity when you, your surroundings, your clothing, or your tools are wet.

3. Use insulated hand tools and double insulated power tools. 4. Never remove the 3rd grounding prong from an electrical cord. 5. Permanently remove frayed or defective extension cords from the workplace. 6. Maintain at least 10 feet clearance while working near overhead power lines.

Preventing Electrical Hazards

There are various ways of protecting people from the hazards caused by electricity, including insulation, guarding, grounding, and electrical protective devices. Workers can significantly reduce electrical hazards by following some basic precautions:

2. LOOK UP when you are on roofs, haystacks, in trees or atop other structures that could put you within reach of power lines.

3. DON'T TOUCH any wires or cables lying on the ground. Always assume a downed power line or cable is hot, keep others away and report immediately to your cooperative or power supplier.

4. CALL BEFORE YOU DIG in areas where there might be underground utilities. Locates are free and could save your life or the expense of costly repair work. Call two working days Before You Dig (ID, MT, ND, OR, WA, WY) 1-800-424-5555.10. OBEY WARNING SIGNS on electrical installations such as substation fences and enclosures. "Danger - High Voltage" means exactly what it says. Make sure your children understand the facts.

Kids and Electricity

Children are curious by nature. But a little curiosity about things electrical can be hazardous. Stay safe by learning more about electricity.

Kids can have fun learning in our Safety For Kids section. Take a quiz or color a picture right on our web page. If you just want some handy safety tips, they are provided below.

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The following tips can help keep kids healthy and happy indoors:

Teach your kids not to poke things into electrical outlets, toasters, or any other appliances, on or off. Use plug covers or inserts in all your outlets. They're available in almost any home supply store.

Move appliances to the back of counters, and keep electrical cords away from areas where kids can reach. Teach kids that electricity and water never mix. Keep all radios, hair dryers and other appliances secured or out of bathrooms. And remember to set a good example.

Make it a habit to unplug small appliances when they're not in use, and push them to the back of your counters. And make sure you use all three prongs of your electric plugs, and replace worn or frayed cords immediately. Never force a plug into an outlet if it doesn't fit, and never nail or tack cords to walls or floors.

Here are a few outdoor tips for kids:

Electricity can travel down kite strings or wires. Teach your children never to fly kites or balloons near any power lines. Accidents can shock, or start fires.

Make sure kids know that if their toys or other objects get caught in electrical equipment, they should leave them and find an adult to help. Balls or other objects tossed or falling into an electrical substation should be left. Call Dominion or the utility involved and have a utility employee retrieve the item.

Teach your kids to recognize "Danger" signs, and not to climb in trees if power lines pass through or near it. And tell them that pad-mounted transformers, those metal cabinets on concrete pads are not safe places to play.

Downed power lines are big trouble for kids, too. Teach your children to stay well away from them, and to call 911 immediately. Make sure they always assume that any power line is fully charged and is not turned off.

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Experiment 1 : To prepare an extension board.Equipment/ Tool Required: Plier, test pen, screw driver, knife, poker, Series testing board and multimeter,

switch 5A, socket 5A, switch board, switch sheet 8”x5”.Learning Object: To practice how to make an extension board.Reference Drg. No. LPU/ELECT/05

Procedure: Do as follow:1. Cut the switch sheet as per requirement.2. Fixed two switches and two sockets on switch sheet.3. Now make the connection as per circuit diagram, connected phase wire to socket

through their respect switch and neutral and earth wire directly to socket Result: Now we are extend power supply to other place through extension board.

Reference book:1. Estimating and coasting by Surjit singh.2. Workshop practice by Tirlok Singh.

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EXPERIMENT - 2: To prepare the Tube Light circuit.

TOOLS REQUIRED: Screw driver, combination plier, line tester, series test lamp, Side cutting Pliers, Poker, Hammer etc.

MATERIALS REQUIRED : PVC tape, connecting wires, tube rod 40w,choke 40 w ,tube starter 40w,tube fitting 40w,Starter base, Tube Holder 2,Flexible wire , Screws etc.

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PROCEDURE:

1. Make the tube light circuit as shown in circuit diagram. 2. Connect phase wire through choke.3. Connect neutral wire direct to rod.4. Connect starter to two spare terminals. PRECAUTIONS:

1. Don’t touch any live terminal. 2. Be alert while working.3. Always use insulated tools.

SCOPE OF THE RESULT:

Students will be familiar with making of tube light.

VIVA QUESTIONS:

1. Which type of switch is used?2. Working of choke coil.3. Which filament (material) is used.4. Which chemical gas is used in tube light?6. What is the function of tube starter?7. Which current rating is used in house wiring.8. Which type of voltage is used for home appliances?9. What is the frequency range of house wiring supply?10. Identify the terminals of energy meter.

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EXPERIMENT-3: To design different Electrical Fuse of different current rating using Datasheet.

Material Required:1. Fuse holder 2. Fuse Cap 3. Striker Pin4. Fuse wire (0.5 A, 0.75A, 1.5A)5. kit-Kat fuse

Equipment Required:1. Multimeter2. Tweezers3. Soldering iron4. Solder wire5. Flux6. Disordering pump

Learning Objective: 1. To get familiar with fuse. 2. To know about fuse ratings.

THEORY:

In electronics and electrical engineering a fuse is a type of sacrificial over current protection device. Its essential component is a metal wire or strip that melts when too much current flows, which interrupts the circuit in which it is connected. Short circuit, overload or device failure is often the reason for excessive current.

A fuse interrupts excessive current (blows) so that further damage by overheating or fire is prevented. Wiring regulations often define a maximum fuse current rating for particular circuits. Overcurrent protection devices are essential in electrical systems to limit threats to human life and property damage. Fuses are selected to allow passage of normal current and of excessive current only for short periods system.

1. Current Rating Of Fuse Element: It is the value of maximum current which a fuse element has to carry without overheating itself . Its value is less than the minimum fussing current and depends upon the permissible temperature rise of the contact of the fuse holder.

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2. Fussing Current : It is minimum value of current at which the fuse element melts and thus disconnects the circuit.

I=Kd3/2

Where K is the constant called the fuse constant and its value depends upon the material and diameter of the wire.

S No. Metal Value of K

When d is in cm When d is in mm

1. Copper 2530 80

2. Aluminum 1870 59

3. Tin 405.50 12.8

4. Lead 340.6 10.8

PROCEDURE:

1. Main supply is provided by the electricity board and provides cut out on neutral and fuse on phase wire.

2. After energy meter a main board is fixed, which has double pole main switch fuses for all circuits, cut out on neutral wire and earth wire which is connected to earth.

3. Beyond the switch, there are the main and sub distribution boards which supplies power to various installations, the whole system is shown in the figure.

SCOPE OF THE RESULT : THEY WILL BE ABLE TO CHECK CONTINUITY THROUGH THE MULTIMETER AT THE BOTH END OF FUSE.

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EXPERIMENT-4: To design the fire alarm circuit.

Equipment Required: Quantity

1. Bread board 1no.2. Multimeter 1no.3. Power supply 1no.4. Connecting leads ---

Material Required:

1. IC555 1no.2. BC548/558 1each3. SL100B 1no4. LED 1no5. THERMISTOR 47ohm (negative coefficient)6. Diode IN 4001 1no7. Speaker 8ohm/1W 1no 8. C1,C2,C3 10µF/16V,0.04µF,0.01µF (1 each)9. R1-R8 470Ω/33K/560Ω/470Ω,47K,2.2K,470Ω,470Ω Learning Objective :

To learn about different functions of various electronic devices such as IC555 timer, thermistor, LED and transistors.

THEORY

The circuit using a thermistor and a timer is used to design a fire alarm circuit. The circuit is as simple and straight forward so that, it can be easily implemented. The thermistor offers a low resistance at high temperature and high resistance at low temperature. This phenomenon is employed here for sensing the fire.

The IC1 (NE555) is configured as a free running oscillator at audio frequency. The transistors T1 and T2 drive IC1. The output (pin 3) of IC1 is couples to base of transistor T3 (SL100), which drives the speaker to generate alarm sound. The frequency of NE555 depends on the values of resistances R5 and R6 and capacitance C2.When thermistor becomes hot, it gives a low-resistance path for the positive voltage to the

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base of transistor T1 through diode D1 and resistance R2. Capacitor C1 charges up to the positive supply voltage and increases the the time for which the alarm is ON. The larger the value of C1, the larger the positive bias applied to the base of transistor T1 (BC548). As the collector of T1 is coupled to the base of transistor T2, the transistor T2 provides a positive voltage to pin 4 (reset) of IC1 (NE555). Resistor R4 is selected s0 that NE555 keeps inactive in the absence of the positive voltage. Diode D1 stops discharging of capacitor C1 when the thermistor is in connection with the positive supply voltage cools out and provides a high resistance path. It also inhibits the forward biasing of transistor T1.

Circuit diagram :

PROCEDURE: 1. Connect the circuit has shown in the circuit diagram.2. Apply the input voltage at input terminals from the power supply UP TO 6V.3. Wait few minutes (1-2 min.) to heat up the thermistor through its power

supply.4. No external heat will be provided on thermistor.5. Switch off the power supply.6. Follow the procedure again by changing the value of capacitance.

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OBSERVATION:

1. Observe the output frequency through CRO---------------.2. Observe the output voltage (Vpp) ------------------.

SCOPE OF THE RESULT : Check the output (sound) through speaker when

thermistor sense heat (voltage).

VIVA QUESTIONS :

1. What is the full form of LED?

2. What is the function of thermistor in this circuit?

3. Which type of thermistor is used in this circuit?

4. Define knee voltage of diode.

5. Which type of diode having knee voltage 0.7v/0.3v?

6. Which device is used as a output device in this circuit.

7. Which component is used to generate sound?

8. What is the purpose of using IC555?

9. Why we have used PNP transistor in this circuit.

10. Why 555 IC is called as TIMER.

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Experiment-5: To do soldering practical on general PCB.

Equipment Required : Multimeter to test the continuity that soldering has done properly or not.

Material Required:

S.No. Requirements Qty.1 Solder Iron(25W) 12 Flux 1 box3 Solder Wire 1 m4 Resistors 2 5 PCB board 1

6 Sand paper 1 7 Transistor ,IC base 2 each 8 Wick 1 9 Brush (3 No.) 1

Learning Objective:

1. To learn about soldering.2. They get familiar with general purpose PCB.

THEORY : A pencil type soldering iron with 25 W electric heater and needle tip is used for

general purpose PCB With IC base closely spaced. Different capacities of heating element and different shapes of bits are used for efficient soldering of different components.

Soldering 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.

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

PROCEDURE:

Selection of soldering iron :1. An iron should be between 25 to 35 W.The iron temperature should not be

exceed 300 C to 400 C and contact time not more than 5 seconds. Component Preparation : 2. The component lead wire is rubbed with sand 3. Paper, brushed with liquid flux and dry with paper.4. General purpose PCB: general PCB should be cleaned (remove the oxide

layer from the metal) with the help of sandpaper.

SOLDERING TECHNIQUE: 1. Touch the tip of iron to most of the element of the joints.

2. Place the iron at 45 angles.3. Place the Wire near the iron and move it over the joint. 4. The molten metal should cover all the elements of the joint. 5. Remove solders wire. 6. Remove iron.

OBSERVATION:1. The quantity of solder should be optimum.2. There should be no flux or oxide on the surface. 3. The surface of solder should be smooth. 4. The bending shape of components while placed the PCB should be proper.

Scope of the Result : Students will be able to perform soldering on PCB.

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PRECAUTIONS:

1. It should not be obscure the shape of component.2. There should not be any protrusions.3. Place iron at 45 angles.4. Solder surface should be oxide less (as possible as max.).

VIVA QUESTIONS:

Q1. Which layer is coated on PCB?Q2. What is full form of PCB?Q3. Solder wire is made of which material.Q4 .Why we use the flux during soldering.Q5. During soldering which angle should be maintained of the soldering iron by the base?Q6. For disordering which apparatus is used?Q7. Which type of soldering iron (W/TIP) to be select for the soldering? Q8. What is the width of copper layer used on PCB?Q9. Why we don’t prefer high voltage soldering iron.Q10.What should be the contact time between the component and soldering iron(on mode).

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EXPERIMENT- 6 : To design the electronic door bell.

EQUIPME NTS Required: Quantity

1. Multimeter 1no2. Bread Board 1no3. Regulator power supply 1no4. CRO 1no

Material Required :

1. IC UM 66 1no2. BC 548 2no3. SPEAKER 1no4. POT 10K 1no5. POT 100K 1no6. CAP 220mf/10v 2no7. ON/OFF switch 1no

Learning Objective : To get an idea about how to make small electronic projects.

THEORY: A simple door bell circuit diagram is shown in figure. The circuit is built around IC UM 66 A popular type number used for constructing other musical project. The IC can drive directly a micro buzzer but needs a driver stage to operate the speaker. IC UM 66 comprises a ROM memory of 64 notes and has a built in oscillator and a pre amplifier. Transistors Q1 and Q2 constitute the complementary symmetry audio amplifier that generates sufficient drive power for the speaker. Switch is a micro switch with normally closed contact connected in the circuit. The switch is pressed to open the contact momentarily.

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PROCEDURE:

1. Connect the circuit as shown in the circuit diagram.2. Apply the input voltage at input terminals from the power supply.3. When not occurs the proper output vary pot1 and pot2 until the output comes out

to be distortionless.

OBSERVATION: Observe the wave shape by CRO at the output (speaker) of the circuit and find the Vpp.

Scope of the Result :

The maximum output signal amplitude which is un- distorted -----------Vpp.

PRECAUTIONS:

1. Use the BC 548 NPN transistors for this experiments. Match can be done by observing hfe of the transistor using multimeter.

2. Transistor recommended is BC548.3. Do not short the output which will burn of the transistor.

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VIVA QUESTIONS :

1. Which type of transistor is used in this circuit? 2. Identify various terminals of transistor.3. What do you mean by POT.?4. What is the function of IC UM66?5. How we can change the sound without removing UM66.6. Which type of capacitor is used in this circuit?7. What is the function of capacitor in this circuit?8. What do you mean by frequency?9. Is transistor an active element or Passive element?10.What is the difference between active and passive element.

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EXPERIMENT- 7 : Design of house hold wiring for Tube light, Fan and bulb and main switch.

Material Required: 1. Switch 5A = 2, Socket 5A=01, Wire 1mm =10mtr.2. Switch Board 7” * 4” =01 Switch sheet 8’’ *5 =01, Lamp 60W =013. P.V.C conduit pipe 1’’ =5 mtr. Lamp holder =01

Equipment Required :1. Combination Pliers2. Screw Driver 6’’3. Test Pen 4. Claw Hammer5. Poker6. Knife7. Single phase energy meter, 10-40-/A, DP.-main switch-16/A, fuse -16/A.

Learning Objective: 1. To learn about wiring at home.2. They will know about house hold wiring for tube light, fan and

bulb.

CIRCUIT DIAGRAM :

PROCEDURE:

Main supply is provided by the electricity board and provides cut out on neutral and fuse on phase wire.

After energy meter a main board is fixed, which has double pole main switch fuses for all circuits, cut out on neutral wire and earth wire which is connected to earth.

Beyond the switch, there are the main and sub distribution boards which supplies power to various installations, the whole system is shown in the figure.

PRECAUTIONS: 1. Connection should be tight.2. Joint should cover with insulation tape.3. Conductor should not be overlong.

4. Line wire should always be connecting through switch.

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.

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Scope of the result : They will be able to perform house hold wiring for tube light, fan and bulb.

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Experiment:8aIdentifying external ports and interfacing

Objective:To learn about different ports and how to connect devices to themThis diagram shows different ports available on the back panel ofthe PC

Parallel port (LPT parallel port):As shown in the diagram parallel port with 25-pins can be used to connect aparallel port printer. Previously dot matrix, ink jet, bubble jet printers etc wereconnected to parallel port. Nowadays-parallel port is used to connect Dot-Matrixprinters.

Serial port:As shown in the diagram serial ports with 9-pins protruding outwards can beused to connect modem but it can also be used for connecting mouse, providedserial port mouse is available.VGA Port:VGA port which has 15-pins is used to connect a monitor.PS/2 Port:Two 6-pin PS/2 ports are there, one is violet to which keyboard is connected

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and other is Light green to which mouse is connectedUSB Port:Connecting a USB device to a computer is simple — you find the USB connectoron the back of your machine and plug the USB connector into it.USB pots are used to connect to Injket printers, Web Cams, Scanners etc.Ethernet Port:Ethernet port is used to connect a computer on network through RJ-45 connector.Game Port:Game Port is used to connect joystick, which is usually used in video gamesThree more ports are available for multimedia connections. Green port isused connect speakers, blue port is used to connect headphones and light Orangeis used to connect microphone.

Output:

ExperimentIdentifying PC cards and interfacing.Objective : To identify different PC cards and to learn how to install them.Sound cardA sound card or audio board, which allows computers to output audio signalsthrough speakers and or headphones.

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Sound Card

Video cardThe video card is responsible for creating all that you see on your computermonitorVGA Card

Network cardThis piece of hardware allows your computer to be connected to a network ofother computers (known as a LAN or Local Area Network)Network Card

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Procedure to install a sound cardIn this example we are going to install a sound card.NOTE: It is best not to install all your PCI hardware if you are buildingfrom scratch. Only install your video card and sound card right now.Once you have your operating system installed, turn off the computerand install the other components. This saves you from possible problemswhen loading up for the first time.1. Remove any unnecessary temporary metal plates. Only remove the metalplates from the slots you are going to use. If you do not remove these, youcannot install any PCI components. Most either unscrew or pop out.

2. Locate PCI Slots on Motherboard. Your PCI Slots should look similar tothe ones in the image below

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Experiment:2 83. Line up component with PCI slot and install. Simply line up the componentwith the slot and gently press down on both sides until it slides in place

4. Insert screw. There is only one screw needed to secure each PCI componentin place.

5. Give it CD Sound. Remember that audio cable from the CD-ROM drive?Now we will connect the other end of it.

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If you want to hear audio when play a cd in your CD-ROM, you need to connectthe CD-ROM to the Sound Card (or motherboard if your sound card is integratedin) using the audio cable as seen below. Refer to your sound card owners manualfor correct placement.If you did not purchase a sound card and you have one integrated into yourmotherboard, refer to your motherboard owner’s manual for correct placement6. Repeat for any other components. Every component is different but as longas its PCI compatible, it is installed the same way (except for the audio cable. It

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Experiment-9: To do soldering practical on general PCB.

Equipment Required : Multimeter to test the continuity that soldering has done properly or not.

Material Required:

S.No. Requirements Qty.1 Solder Iron(25W) 12 Flux 1 box3 Solder Wire 1 m4 Resistors 2 5 PCB board 1

6 Sand paper 1 7 Transistor ,IC base 2 each 8 Wick 1 9 Brush (3 No.) 1

Learning Objective:

1. To learn about soldering.2. They get familiar with general purpose PCB.

THEORY : A pencil type soldering iron with 25 W electric heater and needle tip is used for

general purpose PCB With IC base closely spaced. Different capacities of heating element and different shapes of bits are used for efficient soldering of different components.

Soldering is the process of connecting the parts by ensuring metal continuity. The Process consists of:

2. 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.

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PROCEDURE:

Selection of soldering iron :5. An iron should be between 25 to 35 W.The iron temperature should not be

exceed 300 C to 400 C and contact time not more than 5 seconds. Component Preparation : 6. The component lead wire is rubbed with sand 7. Paper, brushed with liquid flux and dry with paper.8. General purpose PCB: general PCB should be cleaned (remove the oxide

layer from the metal) with the help of sandpaper.

SOLDERING TECHNIQUE: 1. Touch the tip of iron to most of the element of the joints.

2. Place the iron at 45 angles.3. Place the Wire near the iron and move it over the joint. 4. The molten metal should cover all the elements of the joint. 5. Remove solders wire. 6. Remove iron.

OBSERVATION:1. The quantity of solder should be optimum.2. There should be no flux or oxide on the surface. 3. The surface of solder should be smooth. 4. The bending shape of components while placed the PCB should be proper.

Scope of the Result : Students will be able to perform soldering on PCB.

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PRECAUTIONS:

1. It should not be obscure the shape of component.2. There should not be any protrusions.3. Place iron at 45 angles.4. Solder surface should be oxide less (as possible as max.).

VIVA QUESTIONS:

Q1. Which layer is coated on PCB?Q2. What is full form of PCB?Q3. Solder wire is made of which material.Q4 .Why we use the flux during soldering.Q5. During soldering which angle should be maintained of the soldering iron by the base?Q6. For disordering which apparatus is used?Q7. Which type of soldering iron (W/TIP) to be select for the soldering? Q8. What is the width of copper layer used on PCB?Q9. Why we don’t prefer high voltage soldering iron.Q10.What should be the contact time between the component and soldering iron(on mode).

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