Engineering Practices Lab Mannual Author Gandhi.R ,GNANAMANI COLLEGE of ENGINEERING,NAMAKKAL

DEPARTMENT OF EEE

LAB MANNUAL

GANDHI.R ,. ME

AP/EEE

[email protected]

+919942421427

GNANAMANI COLLEGE OF ENGINEERING,NAMAKKAL-18

DEPARTMENT OF ELECTRICAL AND ELECTRONICS ENGINEERING

LAB CODE&NAMEGE2116-Engineering Practices Laboratory (Common to all B.E. / B.Tech. Degree Programmes)

SEMESTER I

GROUP B (ELECTRICAL & ELECTRONICS)

III ELECTRICAL ENGINEERING PRACTICE

1. Residential house wiring using switches, fuse, indicator, lamp and energymeter.

2. Fluorescent lamp wiring.

3. Stair case wiring

4. Measurement of electrical quantities – voltage, current, power & powerfactor in RLC

circuit.

5. Measurement of energy using single phase energy meter.

6. Measurement of resistance to earth of electrical equipment.

IV ELECTRONICS ENGINEERING PRACTICE

1. Study of Electronic components and equipments – Resistor, colour coding

measurement of AC signal parameter (peak-peak, rms period, frequency) using

CRO.

2. Study of logic gates AND, OR, EOR and NOT.

3. Generation of Clock Signal.

4. Soldering practice – Components Devices and Circuits – Using general purpose

PCB.

5. Measurement of ripple factor of HWR and FWR.

INSTRUCTIONS TO THE CANDIDATE:

You are doing experiments with electric power. it may cause even a final or loss of

energy of your body system. to avoid this please keep in mind the followings.

1. In case of any wrong observation, you have to switch off the power supply with it.

2. You have to wear shoes compulsorily.

3. Once you enter in to lab keep silence.

CIRCUIT SYMBOL FOR ELECTRICAL ITEM

S.N

O

COMPONENT NAME SYMBOL

1 Direct current

2 Alternating current

3 Resistance

4 Capacitance

5 Inductance

6 Fuse

7 Main switch

8 Energy meter

9 One way switch

10 Two way switch

11 Lamb

12 Single tube light

13 Bell

14 Buzzer

15 Siren

16 Horn

17 Ceiling fan

18 Fan regulator

19 Earth

20 Heater

21 Two pin socket with 5Aswitch

23 Three pin socket with 5A

switch

24 Three pin socket with 15A

switch

25 Single phase alternating current

26 Three phase alternating current

27 Neutral link

28 Dc generator

29 Dc motor

30 AC generator

31 AC motor

32 3 pin socket

33 Choke

34 Cell

35 Battery

36 Dc volt meter

37 DC ammeter

38 Watt meter

39 Energy meter

WIRING DIAGRAM

Ex.no:1 Residential House Wiring

Date:

Aim,

To construct the residential house wiring using switches, fuse, indicator, lamp and energy

meter.

Materials required:

S.no Components Qty

1. Bulb holder 1 no

2. Bulb 1 no

3. Fan 1no

4. Regulator 1 no

5. Single way switch(5Amps) 3no

6. Switch box 1no

7. Connecting wires As required

8. Main switch 1no

9. Energy meter 1no

10. Indicator 1 no

Procedure:

1. Mark the location of electrical items on the given wooden board.

2. Mark lines for wiring on the wooden board.

3. The required length of PVC pipe can be fixed along the line with the help of clips.

4. The wires of required length and colour were chosen and the wiring is being made

through PVC pipe.

5. The bulb holder and switches are fixed in the corresponding location.

6. Use the red holder colour wire for phase line to the bulb through two way switch.

7. The point of the bulb is connected to the neutral line.

8. The red and black wire terminals are connected to main switch.

9. Check the lamb, fan and plug point.

Result:

Thus the wiring for house was prepared and tested.

EX.NO: 2 FLUORESENT LAMP WIRING

Aim ,

To check and assemble the accessories of a tube light.

Materials required:

S.no Components Qty

1. Fluorescent lamp with light fitting 1 no

2. Wood screws 10no


`

Procedure,

1. Assemble the fluorescent tube accessories like stater, holder and, choke in the

fitting base with the help of screws.

2. Finally the tube is fixed in the tube holder to light it.

Result:

Thus the checking and assembling the accessories of a fluorescent lamp is done.

WIRING DIAGARAM

STAIR-CASE WIRING

EX.NO:3

AIM,

To construct a staircase wiring in which one lamp controlled by two switches.

Materials required:

S.no Components Qty

1. Bulb holder 1 no

2. Bulb 40 watts 1no

3. Two way switch 1 no

4. Connecting wire As required

Procedure

1. Mark the location of switch and bulb the given wooden board.

2. Mark the lines for wiring on the wooden board.

3. The required length of PVC pipe can be fixed along with the help of clips.

4. The wires of required length and colour were chosen and the wiring is being made

through the pipe.

5. The bulb holder and switches are fixed in the corresponding location.

6. Use the red colour wire for phase line to the bulb through two way switch.

7. Another point of the bulb is connected to the neutral line. Using black wire.

8. The red and black wire terminals are connected to main switch.

9. The supply was given to the circuit.

10. The supply was being made to glow by operating the switches as given below.

Position of the switch(s1) Position of the switch(s2) Condition of lamp (L)

1 1

1 2

2 1

2 2

Result:

Thus the staircase wiring for the bulb was prepared and tested.

TABULAR COLOUM:

s.no Volt in

(v)

VR VL VC I(amps) App.P=VxI W

true

power

P.F Measured

P.F

Reading

1 100V

2 200V

3 200V

4 200V

5 200V

MEASUREMENT OF ELECTRICAL QUANTITIES

VOLTAGE, CURRENT, POWER & POWER FACTORING RLC CIRCUIT

Ex.no:4

Aim,

To measure the electrical measurement of electrical quantities -voltage, current, power

and power factoring RLC circuit.

Apparatus required

S.no Apparatus name Range Qty

1. voltmeter (0-300 )V MI 1no

2. ammeter (0-2)A 1no

3. wattmeter 5AMPS/250V 1no

4. pf meter 5A/250V 1no

5. ohm meter 1 KΩ 1no

6. auto-transformer 1no

7. resistor 400 Ω/1A 1no

8. inductor variable 1no

9. capacitor variable 1no

PRECEDURE:

1. Connections are made as per the circuit diagram.

2. Set the auto transformer to have a zero output.

3. Gradually increase the output voltage until its 100v.

4. Measure the corresponding current .note down the reading in the given table. Also

read the watt meter and the power factor meter and record in table.

5. Calculate the apparent power from the voltmeter and ammeter readings.

Apparent power= V X I

COS =True power/apparent power

6. Verify the measured power factor with the calculated power factor.

7. Increase the voltage to 200v and repeat the above steps 4 to 7 times.

RESULT

Thus the R-L-C circuit voltage, current, power and power factor are measured and

values are calculated.

TABLE:

S.no Earth resistance value (megger readings) MΩ

AVERAGE VALUE

Ex.no:5 Measurement of resistance to earth of an electrical equipment AIM, To measure the earth resistance of given electrical equipment (transformer). Apparatus required

S.no Components Description Qty

1. Transformer 0-230v/110v 1no

2. Megger 1no

3. DPST 1no

Procedure

1. Connection are given as per the circuit diagram.

2. The DPST should keep open.

3. Supply the desired voltage to megger for its operation for one minute.

4. Take the readings of megger.

5. Repeat the step 3 for at least five times take the average value. The average value

gives the earth resistance of the given transformer.

Result:

Thus the earth resistance of the given transformer was found by using megger.

CIRCUIT DIAGRAM

TABULAR COLUMN:

S.NO LOAD

CURRENT

I

(Amps)

WATTMETER

READING t

(Sec)

INDICATED

POWER

W1

(watts)

%

ERROR

MODEL GRAPH:

+Ve

% Error

0

Wi

-Ve

EX.NO:6

MEASUREMENT OF ENERGY USING SINGLE PHASE ENERGY METER.

AIM:

To calibrate the given single phase energy meter at unity and other power factors

OBJECTIVES

1. To study the working of energy meter

2. To accurately calibrate the meter at unity and other power factor

3. To study the % of errors for the given energy meters

EQUIPMENT

1. Energy meter – 1 No

2. Wattmeter – 1 No

3. Stop watch – 1 No

4. M.I Ammeter – 1 No

5. M.I Voltmeter – 1 No

DETAILS:

EXERCISE

1. Measure the experimental energy consumed

2. Calculate the theoretical energy

3. Calculate the percentage of error

4. Draw the calibration curve

RATED CURRENT

RATED VOLTAGE

FREQUENCY

REVOLUTIONS/KWH

PROCEDURE:

1.Connections are given as shown in the circuit diagram.

2.Supply is switched ON and load is increased in steps, each time noting the readings of

ammeter and wattmeter. Also the actual time taken for 1 revolution of the disc is

measured using stop watch.

3.Step 2 is repeated till rated current of the energy meter is reached.

4. % Error is calculated and calibration curve is drawn.

CALCULATION:

Let x revolution / kwh be the rating.

Now x revolution = 1 kwh

= 1* 3600*1000* watt-sec.

Constant k of energymeter = 3600 * 103/x watt-sec

For each load indicated power Wi is given as Wi = k/t watts

Where

K= energymeter constant (watt-sec)

T= time for 1 revolution(sec).

Actual power is indicated by the wattmeter reading.

% error = Wi-Wa/Wi* 100.

It can be zero +ve or –ve.

RESULTS:

From the calibration curve it is possible to predict the error

in recording the energy. So the correction can be applied to the energy meter

reading so that correct energy reading can be obtained and used.

Study of electronic components Aim,

To understand the basics concepts of electronics components and their use age.

Resistors

Component Circuit Symbol Function of Component

Resistor

A resistor restricts the flow of current, for example to limit the current passing through an LED. A resistor is used with a capacitor in a timing circuit. Some publications still use the old resistor

symbol:

Variable Resistor (Rheostat)

This type of variable resistor with 2 contacts (a rheostat) is usually used to control current. Examples include: adjusting lamp brightness, adjusting motor speed, and adjusting the rate of flow of charge into a capacitor in a timing circuit.

Capacitors


Capacitor

A capacitor stores electric charge. A capacitor is used with a resistor in a timing circuit. It can also be used as a filter, to block DC signals but pass AC signals.

Diodes


Diode

A device which only allows current to flow in one direction.

LED Light Emitting Diode

A transducer which converts electrical energy to light.

Zener Diode

A special diode which is used to maintain a fixed voltage across its terminals.

Photodiode

A light-sensitive diode.

Transistors


Transistor NPN

A transistor amplifies current. It can be used with other components to make an amplifier or switching circuit.

Transistor PNP

A transistor amplifies current. It can be used with other components to make an amplifier or switching circuit.

Phototransistor

A light-sensitive transistor.

Audio and Radio Devices


Microphone

A transducer which converts sound to electrical energy.

Earphone

A transducer which converts electrical energy to sound.

Loudspeaker


Piezo Transducer


Amplifier (general symbol)

An amplifier circuit with one input. Really it is a block diagram symbol because it represents a circuit rather than just one component.

Aerial (Antenna)

A device which is designed to receive or transmit radio signals. It is also known as an antenna.

Sensors (input devices)


LDR

A transducer which converts brightness (light) to resistance (an electrical property). LDR = Light Dependent Resistor

Thermistor

A transducer which converts temperature (heat) to resistance (an electrical property).

Logic Gates

Logic gates process signals which represent true (1, high, +Vs, on) or false (0, low, 0V, off). For more information please see the Logic Gates page. There are two sets of symbols: traditional and IEC (International Electrotechnical Commission).

Gate Type

Traditional Symbol

IEC Symbol Function of Gate

NOT

A NOT gate can only have one input. The 'o' on the output means 'not'. The output of a NOT gate is the inverse (opposite) of its input, so the output is true when the input is false. A NOT gate is also called an inverter.

AND

An AND gate can have two or more inputs. The output of an AND gate is true when all its inputs are true.

NAND

A NAND gate can have two or more inputs. The 'o' on the output means 'not' showing that it is a Not AND gate. The output of a NAND gate is true unless all its inputs are true.

OR

An OR gate can have two or more inputs. The output of an OR gate is true when at least one of its inputs is true.

NOR

A NOR gate can have two or more inputs. The 'o' on the output means 'not' showing that it is a Not OR gate. The output of a NOR gate is true when none of its inputs are true.

EX-OR

An EX-OR gate can only have two inputs. The output of an EX-OR gate is true when its inputs are different (one true, one false).

EX-NOR

An EX-NOR gate can only have two inputs. The 'o' on the output means 'not' showing that it is a Not EX-OR gate. The output of an EX-NOR gate is true when its inputs are the same (both true or both false).

Resistor values - the resistor colour code

Resistance is measured in ohms, the symbol for ohm is an omega . 1 is quite small so resistor values are often given in k and M . 1 k = 1000 1 M = 1000000 .

Resistor values are normally shown using coloured bands. Each colour represents a number as shown in the table.

Most resistors have 4 bands:

• The first band gives the first digit. • The second band gives the second digit. • The third band indicates the number of zeros. • The fourth band is used to shows the tolerance (precision) of the resistor,

this may be ignored for almost all circuits but further details are given below.

This resistor has red (2), violet (7), yellow (4 zeros) and gold bands. So its value is 270000 = 270 k . On circuit diagrams the is usually omitted and the value is written 270K.

The standard colour code cannot show values of less than 10 . To show these small

values two special colours are used for the third band: gold which means × 0.1 and

silver which means × 0.01. The first and second bands represent the digits as normal. For

example:

red, violet, gold bands represent 27 × 0.1 = 2.7

green, blue, silver bands represent 56 × 0.01 = 0.56

Tolerance of resistors (fourth band of colour code)

The tolerance of a resistor is shown by the fourth band of the colour code. Tolerance is the precision of the resistor and it is given as a percentage. For example a 390 resistor with a tolerance of ±10% will have a value within 10% of 390 , between 390 - 39 = 351 and 390 + 39 = 429 (39 is 10% of 390).

A special colour code is used for the fourth band tolerance: silver ±10%, gold ±5%, red ±2%, brown ±1%. If no fourth band is shown the tolerance is ±20%.

Tolerance may be ignored for almost all circuits because precise resistor values are rarely required.

Expt. No.2 STUDY OF LOGIC GATES

AIM:

To verify the truth table of basic digital ICs of AND, OR, NOT, NAND, NOR, EX-OR

gates.

APPARATUS REQUIRED:

S.No Name of the Apparatus Range Quantity

1. Digital IC trainer kit 1

2. AND gate IC 7408 1

3. OR gate IC 7432 1

4. NOT gate IC 7404 1

5. NAND gate IC 7400 1

6. NOR gate IC 7402 1

7. EX-OR gate IC 7486 1


THEORY:

a. AND gate:

An AND gate is the physical realization of logical multiplication operation. It is

an electronic circuit which generates an output signal of ‘1’ only if all the input

signals are ‘1’.

b. OR gate:

An OR gate is the physical realization of the logical addition operation. It is an

electronic circuit which generates an output signal of ‘1’ if any of the input

signal is ‘1’.

c. NOT gate:

A NOT gate is the physical realization of the complementation operation. It is an

electronic circuit which generates an output signal which is the reverse of the

input signal. A NOT gate is also known as an inverter because it inverts the input.

AND GATE

LOGIC DIAGRAM:

PIN DIAGRAM OF IC 7408 :

CIRCUIT DIAGRAM:

TRUTH TABLE:

INPUT OUTPUT S.No

A B Y = A . B

1. 0 0 0

2. 0 1 0

3. 1 0 0

4. 1 1 1

OR GATE

LOGIC DIAGRAM:


CIRCUIT DIAGRAM:

TRUTH TABLE:

INPUT OUTPUT S.No

A B Y = A + B

1. 0 0 0

2. 0 1 1

3. 1 0 1

4. 1 1 1

NOT GATE

LOGIC DIAGRAM:


CIRCUIT DIAGRAM:

TRUTH TABLE:

INPUT OUTPUT S.No

A Y = A’

1. 0 1

2. 1 0

NAND GATE

LOGIC DIAGRAM:


CIRCUIT DIARAM:

TRUTH TABLE:

INPUT OUTPUT S.No

A B Y = (A . B)’

1. 0 0 1

2. 0 1 1

3. 1 0 1

4. 1 1 0

NOR GATE

LOGIC DIAGRAM:


CIRCUIT DIAGRAM:

TRUTH TABLE:

INPUT OUTPUT S.No

A B Y = (A + B)’

1. 0 0 1

2. 0 1 0

3. 1 0 0

4. 1 1 0

EX-OR GATE

LOGIC DIAGRAM


CIRCUIT DIAGRAM:

TRUTH TABLE:

INPUT OUTPUT S.No

A B Y = A B

1. 0 0 0

2. 0 1 1

3. 1 0 1

4. 1 1 0

d. NAND gate:

A NAND gate is a complemented AND gate. The output of the NAND gate will

be ‘0’ if all the input signals are ‘1’ and will be ‘1’ if any one of the input signal is

‘0’.

e. NOR gate:

A NOR gate is a complemented OR gate. The output of the OR gate will be ‘1’ if

all the inputs are ‘0’ and will be ‘0’ if any one of the input signal is ‘1’.

f. EX-OR gate:

An Ex-OR gate performs the following Boolean function,

A B = ( A . B’ ) + ( A’ . B )

It is similar to OR gate but excludes the combination of both A and B being equal

to one. The exclusive OR is a function that give an output signal ‘0’ when the

two input signals are equal either ‘0’ or ‘1’.

PROCEDURE:

1. Connections are given as per the circuit diagram

1. For all the ICs 7th

pin is grounded and 14th

pin is given +5 V supply.

2. Apply the inputs and verify the truth table for all gates.

RESULT:

The truth table of all the basic digital ICs were verified.

Expt. No. GENERATION OF CLOCK SIGNAL ( MULTIVIBRATOR)

AIM:

To design an Astable multivibrator circuit for the given specifications using 555 Timer

IC.

APPARATUS REQUIRED:

S.No Name of the Apparatus Range Quantity

1. Function Generator 3 MHz 1

2. CRO 30 MHz 1

3. Dual RPS 0 – 30 V 1

4. Timer IC IC 555 1

5. Bread Board 1

6. Resistors

7. Capacitors

8. Connecting wires and probes As required

THEORY:

An Astable multivibrator, often called a free-running multivibrator, is a rectangular-

wave-generating circuit. This circuit do not require an external trigger to change the state

of the output. The time during which the output is either high or low is determined by

two resistors and a capacitor, which are connected externally to the 555 timer. The time

during which the capacitor charges from 1/3 Vcc to 2/3 Vcc is equal to the time the output

is high and is given by,

tc = 0.69 (R1 + R2) C

Similarly the time during which the capacitor discharges from 2/3 Vcc to 1/3 Vcc is equal

to the time the output is low and is given by,

td = 0.69 (R2) C

Thus the total time period of the output waveform is,

T = tc + td = 0.69 (R1 + 2 R2) C

The term duty cycle is often used in conjunction with the astable multivibrator. The duty

cycle is the ratio of the time tc during which the output is high to the total time period T.

It is generally expressed in percentage. In equation form,

% duty cycle = [( R1 + R2) / (R1 + 2 R2)] x 100

PIN DIAGRAM:

CIRCUIT DIAGRAM OF ASTABLE MULTIVIBRATOR

DESIGN:

[ To design an astable multivibrator with 65% duty cycle at 4 KHz frequency, assume C=

0.01 µF]

Given f= 4 KHz,

Therefore, Total time period, T = 1/f = ____________

We know, duty cycle = tc / T

Therefore, tc = ------------------------

and td = ____________

We also know for an astable multivibrator

td = 0.69 (R2) C

Therefore, R2 = _____________

tc = 0.69 (R1 + R2) C

Therefore, R1 = _____________

PROCEDURE:

1. Connections are given as per the circuit diagram.

2. + 5V supply is given to the + Vcc terminal of the timer IC.

3. At pin 3 the output waveform is observed with the help of a CRO

4. At pin 6 the capacitor voltage is obtained in the CRO and the V0 and Vc voltage

waveforms are plotted in a graph sheet.

OBSERVATIONS:

Time period

( No. of div x

Time per div )

S.No

Amplitude

( No. of div x

Volts per div )

tc td

1.

Output Voltage , Vo

2.

Capacitor voltage , Vc

MODEL GRAPH:

RESULT:

The design of the Astable multivibrator circuit was done and the output voltage and

capacitor voltage waveforms were obtained.

CIRCUIT DIAGRAM:

WITHOUT FILTER:

WITH FILTER:

HALF WAVE RECTIFIER

AIM: To construct half wave rectifier and to draw their input and output

waveforms.

APPARATUS REQUIRED:

S.No. Name Range Quantity

1. Transformer 230 V / 6-0-(-6) 1

2. Diode IN4007 1

3. Resistor 1 kΩ 1

4. Capacitor 100µF 1

5. CRO 30 MHz 1

6. Bread Board 1

FORMULA USED:

Ripple Factor =

Where Im is the peak current

THEORY:

Half wave rectifier:

A rectifier is a circuit, which uses one or more diodes to convert A.C voltage into D.C

voltage. In this rectifier during the positive half cycle of the A.C input voltage, the diode

is forward biased and conducts for all voltages greater than the offset voltage of the

semiconductor material used. The voltage produced across the load resistor has same

shape as that of the positive input half cycle of A.C input voltage.

During the negative half cycle, the diode is reverse biased and it does not conduct. So

there is no current flow or voltage drop across load resistor. The net result is that only the

positive half cycle of the input voltage appears at the output.

PROCEDURE:

1. Connect the circuit as per the circuit diagram.

2. Apply a.c input using transformer.

3. Measure the amplitude and time period for the input and output waveforms.

4. Calculate ripple factor.

MODEL GRAPH:

RECTIFIER:

Without filter With filter

Input signal Output signal

Amplitude(V) Time period Amplitude(V) Time period

RESULT:

Thus the half wave rectifier was constructed and its

input and output waveforms are drawn. The ripple factor of capacitive filter is

calculated as

Ripple factor=

FULLWAVE RECTIFIER

FULLWAVE RECTIFIER WITH FILTER

FULL WAVE RECTIFIER

AIM:

To construct a full wave rectifier and to measure dc voltage under load and to

calculate the ripple factor.

APPARATUS REQUIRED:

S.No. Name Range Quantity

1. Transformer 230 V / 6-0-(-6) 1

2. Diode IN4007 2

3. Resistor 1 kΩ 1

4. Capacitor 100µF 1

5. CRO 30 MHz 1

6. Bread Board 1

FORMULA

Ripple Factor = √ [(Im/√2) / (2*Im /л)] 2-1

Where Im is the peak current

THEORY: The full wave rectifier conducts for both the positive and negative half cycles of

the input ac supply. In order to rectify both the half cycles of the ac input, two diodes are

used in this circuit. The diodes feed a common load RL with the help of a centre tapped

transformer. The ac voltage is applied through a suitable power transformer with proper

turn’s ratio. The rectifier’s dc output is obtained across the load.

The dc load current for the full wave rectifier is twice that of the half wave

rectifier. The lowest ripple factor is twice that of the full wave rectifier. The efficiency of

full wave rectification is twice that of half wave rectification. The ripple factor also for

the full wave rectifier is less compared to the half wave rectifier.

. PROCEDURE:

1. Connections are given as per the circuit diagram wiyhout filter.

2. Note the amplitude and time period of the input signal at the secondary

winding of the transformer and rectified output.

3. Repeat the same steps with the filter and measure Vdc.

4. Calculate the ripple factor.

5. Draw the graph for voltage versus time.

MODEL GRAPH

RESULT:

Thus, the full wave rectifier was constructed and the ripple factor was calculated

as

Ripple factor =

Documents

Engineering Practices Lab Mannual Author Gandhi.R ,GNANAMANI COLLEGE of ENGINEERING,NAMAKKAL