DEPARTMENT OF ELECTRONICS &

COMMUNICATION ENGG

GE1101-ENGINEERING PRACTICES LAB

GE1101- ENGINEERING PRACTICE(ELECTRONICS)

SYLLABUS

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

AC signal parameter (peak-peak, rms period, frequency) using CR.

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.

INDEX

Sl. NO. EXPERIMENT

PAGE

NO

1 SOLDERING AND DESOLDERING PRACTISE 1

2

RESISTOR COLOUR CODING AND MEASUREMENT OF AC SIGNAL

PARAMETER 5

3 STUDY AND VERIFICATION OF LOGIC GATES 10

4

MEASUREMENT OF RIPPLE FACTOR FOR HALF WAVE AND FULL WAVE

RECTIFIER 14

5 GENERATION OF CLOCK SIGNAL 19

6B

INTERFACING 8253

WITH 8085 44

6C

INTERFACING 8251

WITH 8085 47

7

INTERFACING

AND PROGRAMMING

OF STEPPER

MOTOR AND DC

MOTOR SPEED

CONTROL.

(a)INTERFACING

STEPPER WITH 8085 50

EX.NO.1 SOLDERING AND DESOLDERING PRACTICE

AIM:

To practice soldering and de-soldering for the given electronic circuit by assembling and

disassembling the resistor R1, R2 and capacitor C1 in the given printed circuit board.

MATERIALS REQUIRED:

Sl. NO.

COMPONENTS

RANGE

QUANTITY

1.

2.

3.

4.

5.

6.

7.

PCB board

Soldering iron

Solder

Flux

Resistor

Capacitor

Nose piler

-

-

35 w

-

-

-

1

1

1

1

2

1

1

THEORY:

SOLDERING:

Soldering is the process of joining thin metal plates or wires made of steel copper or brass. It is

very commonly used to join wires in electrical work and mount electronic components on a circuit board.

The joining material used in soldering is called as soldered or filler rod. An alloy of tin and lead is

commonly used as solder. The flux is used to clean the surface of the plates/ wires to be soldered.

DESOLDERING:

This operation is frequently required during maintenance for replacing a component. It

consists of removal of solder from a previously soldered joint. The following techniques are often used

for this purpose.

1. Use of desoldering pump

2. Use of desoldering tip and dip extractor

3. Use of desoldering braid

4. Use of desoldering bulb.

PROCEDURE:

SOLDERING:

1. Study the given circuit

2. Clean the given PCB board

3. Clean the tip of the soldering iron before heating and also clean the resistor, capacitor which is to be

soldered.

4. Heat the soldering iron and supply solder to the tip as soon as it is hot to melt on it.

5. Bend the resistor (R1) leads to fit into the holes on the board. Insert the resistor (R1) leads to fit as per

the circuit and bend the leads.

6. Apply the hot tip and hold the resistor until soldering.

7. Remove the soldering tip and hold the resistor tightly until the solder has cooled and set.

8. Trim the excess component lead with side cutter.

9. Repeat the above steps to fix other resistor R2 and capacitor C1.

DESOLDERING:

1. Hold the resistor R1 to be unsoldered by a nose piler

2. Place the tip of the soldering iron on the joint until the joint solder is melt

3. When the solder is melted, remove the resistor R1 with a tweezers and brush away molten solder

4. Repeat the above steps to remove resistor R2 and C1.

5. Clean the resistor and capacitor so that they can be used again.

CIRCUIT DIAGRAM:

R11kΩ

R21kΩ

C1

1µF

FRONT SIDE OF THE BOARD:

BACK SIDE OF THE BOARD:

RESULT:

Thus soldering and de-soldering practice is done.

TYPICAL VIVA QUESTIONS:

1. What is soldering?

Soldering is the process of joining thin metal plates or wires made of steel copper or brass.

2. What is flux?

The flux is used to clean the surface of the plates or wires to be soldered.

3. Name some flux types.

1. Rosin based fluxes.

2. Water soluble fluxes.

3. Solvent removable synthetic fluxes.

4. Low solid fluxes.

R1 1kΩ

R2 1kΩ

C1

1µF

R1 1kΩ

R2 1kΩ

C1

1µF

4. What is desoldering?

Desoldering is the process of replacing a component from a previously soldered joint.

5. Name some types of soldering irons.

1. Resistive soldering irons.

2. Soldering gun.

3. Temperature controlled soldering gun.

EX.NO:2

RESISTOR COLOUR CODINGANDMEASUREMENT OF AC SIGNAL PARAMETER

AIM:

To find the resistor colour coding and to measure the AC signal parameter.

MATERIALS REQUIRED:

1. Resistor

THEORY:

Resistor colour coding is used to indicate the values or ratings of resistor. It is also used in

capacitors and inductors. The advantage of colour coding is that essential information can be marked on

small components of cylindrical shape without the need to read tiny printing. Resistor values are always

coded in ohms (Ω).

1. BAND A is the first significant digit of component value.

2. BAND B is the second significant digit.

3. BAND C is the decimal multiplier.

4. BAND D, if present, indicates tolerance of value in percent.

(No colour means 20%)

For example, a resistor with bands of yellow, violet, red and gold will have

first digit 4(yellow), second digit 7 (violet) , followed by 2 (red) zeros; so the resistor value is 4,700Ω.

Gold signifies that the tolerance is ±5%

Actual resistor value = 4700 ±5% w

Resistance Color Code

Colour 1st. Ring

2nd. Ring 3rd. Ring 4th. Ring

1st. Value

2nd. Value Multiplier Tolerance

None - - - +20%

Silver - - - +10%

Gold - - 0,1 +5%

Black -

- 1 -

Brown 1 1 10 +1%

Red 2 2 100 +2%

Orange 3 3 1000 -

Yellow 4 4 10000 -

Green 5 5 100000 +0.5%

Blue 6 6 1000000 +0.25%

Violet 7 7 10000000 +0.1%

Gray 8 8 100000000 +0.05%

White 9 9 1000000000 -

RESISTOR COLOUR CODING:

MEASUREMENT OF AC SIGNAL PARAMETER

AIM:

To measure the AC signal parameter.

APPARATUS REQUIRED:

Sl.NO. APPARATUS SPECIFICATION QUANTITY

1. CRO 20MHZ 1

2. AFO - 1

3. CONNECTING

WIRES

- As Required

THEORY:

An oscilloscope (abbreviated sometimes as scope or O-scope) is a type of electronic test instrument

that allows signal voltages to be viewed, usually as a two-dimensional graph of one or more electrical

potential differences (vertical(Y) axis) plotted as a function of time or of some other voltage

(horizontal(x) axis). Although an oscilloscope displays voltage on its vertical axis, any other quantity that

can be converted to a voltage can be displayed as well. In most instances, oscilloscopes show events that

repeat with either no change, or change slowly.

PROCEDURE:

Connect the components as per the circuit diagram.

Measure the peak to peak voltage and timeperiod

Calculate the Vrms using the formula Vrms=Vm/√2

BLOCK DIAGRAM:

XFG1

XSC1

A B

Ext Trig+

+

_

_ + _

TABULATON:

Sl .NO. Vm Vrms

MODEL GRAPH:

RESULT:

Thus the resistor value was calculated and the AC signal parameter was measured.

TYPICAL VIVA QUESTIONS:

1. What is the use of resistor colour coding?

Resistor colour coding is used to indicate the values or ratings of resistor.

2. What are the types of resistors?

i. Carbon Composition Resistor

ii. Film or Cermet Resistor

iii. Wire-Wound Resistors.

iv. Semiconductor Resistors

3.Define resistor.

Resistors are the electronic components which "resist" the flow of current through an electrical circuit, or

to act as voltage droppers or voltage dividers.

3. Name some characteristics of resistors.

Temperature Coefficient, Voltage Coefficient, Noise, Frequency Response, Power as well as Temperature

Rating, Physical Size and Reliability.

4. What is meant by tolerance in the resistor?

Tolerance is the precision of the resistor and it is given as a percentage. For example a 390Ω resistor with

a tolerance of ±10% will have a value within 10% of 390Ω, between 390 - 39 = 351Ω and 390 + 39 =

429Ω (39 is 10% of 390).

EX.NO.3 STUDY AND VERIFICATION OF LOGIC GATES

AIM:

To study and verify truth table of digital logic gates using the given IC’s

MATERIALS REQUIRED:

5V power supply

IC 7432,IC 7408,IC 7400,IC7404,IC7402,IC7486

LED

Bread board and wires

THEORY:

An electronic gate is a circuit that can operate a number of binary inputs in order to perform a

particular logical function. Logic gates are the basic elements that make up a digital system. In a gate

circuit one or more input voltage is given but only one output voltage is obtained. Various types of gates

available namely the AND,OR,EX-OR,NOT,NAND,NOR,EX-NOR.A table showing all input

combinations and output possibility for a logic circuit is called a truth table.

PROCEDURE:

1. Connect the circuit as shown in the circuit diagram

2. Connect LED at the output pin.

3. Switch ON the power supply and apply binary inputs pin 14 and 7

4. Verify the output for various combinations of input and check the truth table for the given

gate.

5. Repeat the procedure for other gates.

LOGIC DIAGRAM:

AND GATE:

OR GATE:

NOT GATE:

NAND GATE:

NOR GATE:

EX-OR GATE:

EX-NOR GATE:

RESULT:

The truth table of the given logic gates were studied and verified.

TYPICAL VIVA QUESTIONS:

1. Define logic gates.

Logic gates are the basic elements that make up a digital system. The electronic gate is a

circuit that is able to operate on a no. of binary inputs in order to perform a particular logical

function.

2. Name the universal gates.

NAND and NOR gate.

3. What is truth table?

A truth table is a good way to show the function of a logic gate. It shows the output states

for every possible combination of input states. The symbols 0 (false) and 1 (true) are usually used

in truth tables.

4. Give some applications were logic gates is used.

In mobiles, alarms, LEDs, PNP and NPN transistors, FM etc.

5. Give the general expression for AND, OR and NAND gate.

ANDn(x1, x2,...,xn) = x1 * x2 * ... * xn

ORn(x1, x2,...,xn) = x1 + x2 + ... + xn

NANDk(x1, x2,...,xn) = NOT( ANDk(x1, x2,...,xn) )

EX.NO.4 MEASUREMENT OF RIPPLE FACTOR FOR HALF WAVE AND

FULL WAVE RECTIFIER

AIM:

To measure the ripple factor for half wave and full wave rectifier

COMPONENTS REQUIRED:

Sl. NO. COMPONENTS RANGE QUANTITY

1 TRANSFORMER (9-0-9)V 1

2 RESISTOR 470Ω 1

3 CAPACITOR 470µF 1

4 DIODE IN4001 1

5 CRO (0-20)MHZ 1

6 BREAD BOARD

AND WIRES

- As Required

THEORY:

HALFWAVE RECTIFIER:

In half wave rectification, either the positive or negative half of the AC wave is passed, while the

other half is blocked. Because only one half of the input waveform reaches the output, it is very

inefficient if used for power transfer.

FULLWAVE RECTIFIER:

A full-wave rectifier converts the whole of the input waveform to one of constant polarity (positive

or negative) at its output. Full-wave rectification converts both polarities of the input waveform to DC

(direct current), and is more efficient. However, in a circuit with a non-center tapped transformer, four

diodes are required instead of the one needed for half-wave rectification.

PROCEDURE:

1. Connect the circuit as per the circuit diagram.

2. Calculate the average DC value(vdc) using the relation v dc=vm/∏

3. Calculate vrms using the relation vrms=vm/√2.

4. Find the ripple factor from the formula γ=vrms/vdc

CIRCUIT DIAGRAM:

FULLWAVE RECTIFIER

TABULATION:

SL.NO. Vm Vrms

MODEL GRAPH:

INPUT SIGNAL:

FULLWAVE RECTIFIED OUTPUT:

U1

2 D1

50 V

D2

50 V C1470µF

R2

470Ω

HALFWAVE RECTIFIER

TABULATION:

SL.NO. Vm Vrms

MODEL GRAPH:

U1

2

R1470Ω C1

470µF

D1

1BH62

INPUT SIGNAL:

HALFWAVE RECTIFIED OUTPUT:

RESULT:

Thus the ripple factor for the full wave rectifier was calculated.

TYPICAL VIVA QUESTIONS:

1. Define Rectifier.

A rectifier is an electrical device that converts alternating current (AC) to direct current (DC), a

process known as rectification.

2. What is half wave rectifier?

In half wave rectification, either the positive or negative half of the AC wave is passed While the

other half is blocked. Because only one half of the input waveform reaches the output, it is very

inefficient if used for power transfer.

3. What is full wave rectifier?

A full-wave rectifier converts the whole of the input waveform to one of constant polarity (Positive or

negative) at its output. Full-wave rectification converts both polarities of the input waveform to DC

(direct current), and is more efficient.

4. What are the types of rectifiers?

1. Half wave rectifier

2. Full wave rectifier

5. Name some applications of rectifiers.

1. Rectifiers are used in detection of amplitude modulated radio signals.

2. Rectifiers are also used to supply polarized voltage for welding.

3. The primary application of rectifiers is to derive DC power from an AC supply.

EX.NO.5 GENERATION OF CLOCK SIGNAL

AIM:

To generate the clock signal using the given circuit.

APPARATUS REQUIRED:

Sl. NO. COMPONENTS RANGE QUANTITY

1. AFO - 1

2. CRO - 1

3. RESISTOR 1.5KΩ 1

4. CAPACITOR 0.1µf 1

5. BREAD BOARD - 1

6. CONNECTING WIRES

- As Required

THEORY:

In electronics and especially synchronous digital circuits , a clock signal is a signal used to

coordinate the actions of two or more circuits. A clock signal oscillates between a high and a low state,

normally with a 50% duty cycle, is usually in the form of square wave. Circuits using the clock signal for

synchronization may become active at either the rising edge, falling edge or both the edges of the clock

cycle.

PROCEDURE:

1. Connections are made as per the circuit diagram.

2. Connect the resistor to one end of the AFO and the other end to capacitor, which is connected

in parallel to the CRO.

3. Finally the amplitude and time period for the output waveform is noted.

CIRCUIT DIAGRAM:

TABULATION:

AFO

R1 15k

C1

10nF

CRO

WAVE

AMPLITUDE

TIME PERIOD

No. Of Div. in

Y-axis

Volts/Div. Total Amplitude

(Volts)

No. Of Div. in

X-axis

Time/Div.

Total Time period

(msec)

Input signal

Output signal

MODEL GRAPH:

INPUT WAVEFORM:

OUTPUT WAVEFORM:

RESULT:

Thus the clock signal was generated using the given circuit.

TYPICAL VIVA QUESTIONS:

1. What is mean by falling edge?

The condition at which the logic ‘1’ position will transfer to logic ‘0’ condition.

2. What is mean by rising edge?

The condition at which the logic ‘0’ position will transfer to logic ‘1’ condition.

3. What are types of wave generation?

1. Sine Wave

2. Square wave

3. Triangular wave.

4. Name some types of signal generators.

1. Function generators

2. Pitch generators and audio generator

3. Arbitrary waveform generators

5. What are the applications of CRO?

1. One of the most frequent uses of scopes is troubleshooting

malfunctioning electronic equipment.

2. It is used to check newly designed circuitry

3. It is used for software engineers who must program electronics.

I will be grateful to the readers for pinpointing any errors in the manual and I

would welcome constructive criticism and fruitful suggestions for the improvement

of lab manual

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