pdc lab final

8/13/2019 PDC Lab Final

http://slidepdf.com/reader/full/pdc-lab-final 1/27Department of ECE, VVIT, Nambur. 1

1.LINEAR WAVE SHAPING

AIM: 1. To determine perecentage tilt of RC differntiator cicuit for a square wave inputwith

I. RC >> T II. RC = T III. RC << T

2. To determine rise time of RC integrator for a square wave input with

I. RC >> T II. RC = T III. RC << T

APPARATUS:

S.No. Name of the Equipment Range Qty.(nos.)

1 Resistors 4.7 KΩ 1

2 capacitors 0.01µF 1

3 Cathode Ray Oscilloscope 20 MHz 1

4 Function Generator 1 MHz 1

CIRCUIT DIAGRAMS:

PROCEDURE:

To determine percentage of tilt:

1. Connect the circuit as shown in fig.

2. Connect the input and output terminals to both the channels of CRO.

3. Apply input Square wave of 2v (peak to peak) with a frequency of 1KHz.

4. Observe the output waveform on CRO.

5. Compare the theoretical time constants with time constants for output wave forms

measured on C.R.O.

6. Calculate the percentage tilt for the medium time constant.

7. Choose an RC value ( RC << T) such that the circuit acts as differntiator.



To determine rise time:

1. Connect the circuit as shown in fig.

2. Connect the input and output terminals to both the channels of CRO.

3. Apply input Square wave of 2v (peak to peak) with a frequency of 1KHz.

4. observe the output waveform on CRO

5. .Connect the circuit for different time constants and note down the values and wave

forms obtained.

6. Compare theoretically calculated rise time with rise time obtained from output wave

form measured on C.R.O.

7. Calculate rise time for short time constant and choose RC value.

OBSERVATIONS:

To determine % tilt:

R= C= RC= Theoritical tilt(%)= T/2RC×10 Practical tilt(%)=V1-V11

S.No Case

Input

frequancy

(Hz)

T=1/f

(Sec)

V1

(V)

V11

(V)

Theoritical

Tilt(%)

Practical

Tilt(%)

1 RC>>T 200KHz

2 RC=T 21.3KHz

3 RC<<T 2KHz

To determine rise time:

R= C= RC= Theoritical value = T / 2(0.35) Practical value = T2 – T1

S.No Case Input

frequancy

(Hz)

T=1/f

(Sec)

10% of

VO (t1)

90% of

VO (t2)

Theoritical

value

Practical

value

1 RC>>T 200KHz

2 RC=T 21.3KHz

3 RC<<T 2KHz



Thoeritical calculations for tilt:

Case(i) RC>>T = 5µsec /2×47µsec ×100 = 5.32%

Case(ii) RC = T = 47µsec /2×47µsec ×100 = 50%

Case(iii) RC<<T = 0.5µsec /2×47µsec ×100 = 200%

Thoeritical calculations for rise time:

Case (i) RC>>T = 0.35×5/2µsec = 0.875µsec

Case(ii) RC = T = 0.35×47/2µsec = 8.2µsec

Case(iii) RC<<T = 0.35×250µsec = 87.5µsec

RESULT:



MODEL WAVEFORMS:

DIFFERNTIATOR:



INTEGRATOR:



2(A).NON -LINER WAVE SHAPING - CLIPPERS

AIM: To study the various clippers using diodes.

APPARATUS:


1 Resistors 5.6 KΩ 1

2 Diode IN4007 2



5 Bread Board, Connecting Wires -- --

CIRCUIT DIAGRAMS:

Positive clipping:



Negative clipping:

PROCEDURE:

1. Connect the circuit as per the circuit diagram.2. Connect the function generator at the input of the circuit.

3. Apply the sine wave with a desired magnitude.

4. Observe the output wave forms and note down the readings.

5. Repeat steps 1 to 4.

Characteristic Equations:

Positive clipping with out reference: Positive clipping with Positive reference:

Vi < Vr → Vo = Vi Vi < VR → Vo = Vi

Vi > Vr → Vo = Vr Vi > VR → Vo = VR

Positive clipping with Negative reference:

Here the reference voltage is reversed and the Clipping is done in the negative peak.

Negative clipping with Positive reference:

Vi < VR → Vo = VR Vi > VR → Vo = Vi

Result:- Observed and noted the response of different clipping circuits.



MODEL WAVE FORMS

POSSITIVE CLIPPERS



NEGATIVE CLIPPERS



2(B). NON -LINER WAVE SHAPING CLAMPERS

AIM: To observe and note the response of different clamping circuits.

APPARATUS:


1 Resistors 100KΩ 1

2 Capacitors 0.1µf 1

3 Diode IN4007 1




7 Regulated power supply (0-30v) 1

CIRCUIT DIAGRAMS:

Positive clamping



NEGATIVE CLAMPING

PROCEDURE:

1. Connect the circuit as per the first circuit diagram with both the channels of

CRO showing the input and output.

2. Apply the input wave of 10V(p-p) with frequency 1KHz to the circuit.

3. Adjust the both channels of CRO to ground position and then in DC position.

4. Draw the input and output wave forms and indicate the clamping level.

5. Repeat steps 1,2,3,4 for reaming clamping circuits

Precautions:

1. Check the connections before giving the supply.

Result:

Observed and noted the response of different clamping circuits.



Output Waveforms:-

Positive clamping:



Negative Clamping:-



3.STUDY OF LOGIC GATES

AIM: 1. To study Logic Gates

2.To verify the truth tables of AND,OR,NOT,NAND and NOR.

APPARATUS:


1 LED 2

2 Regulated Power Supply (0-30)V 1

3 Transistor BC 107 2

4 Resistors 1 KΩ,2.2KΩ Each 1no.

5 Diodes 1N 4007 2


CIRCUIT DIAGRAMS:

AND GATE

OR GATE



NOT GATE

NAND GATE

NOR GATE



PROCEDURE:

1. Connect the circuit as per the circuit diagram.

2. Apply the voltage of 5V to the circuit.

3. Give the inputs the terminals of the gates where the logic 0 is connected to the ground

and logic 1 is connected to +5V.

4. Compare the truth table where the output of led is glown is equal to logic 1 and the

led is off is equal to logic 0.

5. Check all the truth tables of AND,OR,NOT,NAND and NOR.

PRECAUTIONS:


2. Avoide loose connections.

RESULT:



4.ASTABLE MULTIVIBRATOR

AIM: 1. To observe the operation and wave forms of Astable multivibrator.

APPARATUS:


1 Cathode Ray Oscilloscope 20MHz 1



4 Resistors 1KΩ,15 KΩ Each1no.

5 Capacitors 0.01 µF 2


CIRCUIT DIAGRAM:

PROCEDURE:


2. Apply the VCC as 12V observe wave forms on CRO for VB1, VC1, VB2, VC2.3. Compare the practical value of time period T with theoretical value given by

T=0.69(R1C1+R2C2)

4. Draw wave forms for the output across the collector for both the transistors and also

note down the wave forms at the base of two transistors.



Model Waveforms:

Precautions:


2. Avoid loose connections.

Result:

Observe the operation and wave forms of Astable multivibrator

Theoretical and practical values of T are compared.

Theoretical value of T=

Practical value of T=



5.MONOSTABLE MULTIVIBRATOR

AIM: 1. To observe the operation and wave forms of Monostable multivibrator

APPARATUS:





4 Resistors 10KΩ,100 KΩ,1 KΩ Each -2no

5 Capacitors 0.01 µF 100pF,0.1 µF Each-1no

6 Diode 1N 4007 1



CIRCUIT DIAGRAM:

PROCEDURE:


2. By giving supply voltage of 12V Vcc.

3. Apply the input trigger pulse 900Hz and magnitude of 8V(p-p

4. Observe wave forms on CRO for VB1, VC1, VB2, VC2.

5. Compare the practical value of time period T with theoretical value given by

Precautions:





Model Waveforms:

Result:

Observed the operation and wave forms of Monostable multivibrator


Theoretical value of T=

Practical value of T=



6.UJT AS RELAXATION OSCILLATOR

AIM: 1. To observe the operation and wave forms of UJT relaxation oscillator.

APPARATUS:




3 UJT 2N2646 1

4 Resistors 470Ω,33 KΩ,1 KΩ Each -1no



CIRCUIT DIAGRAM:

PROCEDURE:


2. Apply VBB as +8V.

3. Observe wave forms on CRO for VB1, VB2, VE.

4. Compare the practical value of time period T with theoretical value.

Precautions:





Model Waveforms:

Result:

1. Observed the operation and wave forms of UJT as relaxation oscillator.

2. Theoretical and practical values of T are compared.

3. Theoretical value of T=

4. Practical value of T=



7.SCHMITT TRIGGER

AIM:1. To observe and note Hysteresis curve by using a Schmitt trigge circuit.

2.To measure UTP (upper triple point ) and LT (lower triple point)

from the Hysteresis curve.

APPARATUS:





4 Resistors 3.9KΩ,5.6KΩ,

4.7 KΩ,2.2KΩ,560Ω

Each -1no


6 Capacitor 100µf 1

7 Function Generator 1MHz 1

CIRCUIT DIAGRAM:



PROCEDURE:

DC Analysis:

1. Connect the circuit as per the circuit diagram with power supply Vcc at +8V and Vi

kept 0 volts.

2. Check the status of Q 1 & Q 2.

3. Slowly increase input voltage Vi from ‘0’ and note the “UTP”.

4. Input voltage Vi is further increased, observe that Q 2 remains in ‘OFF’ state. Note

down output voltage VO at collector terminal of Q 2.

5. Reduce slowly the value of V i and note down ‘ LTP`. Note down output voltage Vo at

collector terminal of Q 2

6. Draw the hysteresis curve clearly showing ‘ LTP’ & “UTP”.

AC Analysis:

1. Replace DC voltage with function generator.

2. Apply sinusoidal signal of 8V (p-p) amplitude & 1KHz frequency. Note down input

and output wave forms and calculate ‘ UTP’ &’ LTP’.

3. Observe the hysteresis curve on C.R.O by keeping C.R.O in XY mode where input

signal is connected to “X” channel of C.R.O and output signal is connected to “Y”

channel of C.R.O.

Hysteresis Curve:-



AC ANALYSIS:

MODELWAVE FORMS:

RESULT:



8.BISTABLESTABLE MULTIVIBRATOR

AIM: 1. To observe the operation and wave forms of Bistable multivibrator

APPARATUS:





4 Resistors 10KΩ

1 KΩ

4

2


6 Diode 1N 4007 2



CIRCUIT DIAGRAM:


http://slidepdf.com/reader/full/pdc-lab-final 27/27

PROCEDURE:


2. By giving supply voltage of 12V Vcc.

3. Apply the input trigger pulse 1KHz frequency and magnitude of 5V(p-p using

function Generator.

4. Observe wave forms on CRO for VB1, VC1, VB2, VC2.

5. Compare the practical value of time period T with theoretical value given by

.

Model Waveforms:

Result:

Observed the operation and wave forms of Monostable multivibrator


pdc lab final

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