EE392 Electronic Circuits Lab
Exp. No :
Date:
WAVE SHAPING CIRCUITS USING OPERATIONAL AMPLIFIERS
OBJECTIVE
To study the operation of wave shaping circuits like clippers, clampers, Schmitt trigger and to
verify theoretically expected results.
PRELAB
Design and simulate the following circuits using 741 op-amp. Observe the output waveforms.
1. Positive and negative clippers
2. Positive and negative clampers
3. Schmitt trigger
EQUIPMENT REQUIRED
741 Op-amp
1N4007 diode
2.2kΩ, 1kΩ, 4.7kΩ 10kΩ resistors, ¼ W
10kΩ potentiometer, ¼ W
0-30 V dc dual regulated power supply
30MHz Oscilloscope
3 MHz Function Generator
Digital Multimeter
Breadboard
Connecting wires
THEORY
•
Clipper is a circuit that is used to clip off (remove) a certain portion of the input signal to
obtain a desired output wave shape.
•
In op-amp clipper circuits, a rectified diode ma be used to clip off certain parts of the input signal.
•
In clamper circuits, a predetermined dc level is added to the input voltage. They are also called as dc
inserter or dc restorer.
FURTHER READING
1. Paul B. Zbar, Albert P. Malvino, Michael A. Miller “Basic Electronics A Text – Lab Manual”, Tata
McGraw-Hill, seventh edition, 1995.
2. Ramakand A. Gayakwad, “Op-amps and linear integrated circuits”, PHI learning, 2009.
Electrical & Electronics Engineering, Amrita Vishwa Vidhyapeetham, Coimbatore
EE392 Electronic Circuits Lab
CIRCUIT DIAGRAM
Fig – 1 clipper circuit
Fig – 2 clamper circuit
Electrical & Electronics Engineering, Amrita Vishwa Vidhyapeetham, Coimbatore
EE392 Electronic Circuits Lab
Fig 3 Schmitt Trigger with Zero Reference
Fig 3.1 Schmitt Trigger with Positive Reference
Fig 3.2 Schmitt Trigger with Negative Reference
PRACTICE PROCEDURE
Active clipper
1. Assemble the clipping circuit as shown in fig 1 with R=2.2 kΩ .Use 1N4002 diode.
2. Feed 3VP, 1 kHz sinusoidal input. Observe the input and output voltages on a CRO.
3. Look at the output signal while turning the potentiometer through its entire range.
4. Record your readings in table 2 for a desired clipping level. Plot the input and output
5. voltages on the same scale.
Active clamper
1. Design a positive clamping circuit with clamping level at zero as shown in fig 2. Note
that Vref = 0V. Consider C1 = 0.1µF, R = 4.7 kΩand RL = 10 kΩ. Use 1N4002 diode.
Assemble the circuit.
2. Feed 5VPP, 10 kHz sinusoidal input.
3. Using a CRO observe the input and output voltages simultaneously. Determine the clamping
levels of the output voltage. Tabulate your readings in table 2.
4. Plot the input and output voltages on the same scale.
Electrical & Electronics Engineering, Amrita Vishwa Vidhyapeetham, Coimbatore
EE392 Electronic Circuits Lab
OBSERVATION
Electrical & Electronics Engineering, Amrita Vishwa Vidhyapeetham, Coimbatore
EE392 Electronic Circuits Lab
POST LAB INFERENCE
1. If the diode is reversed in clamper circuit, what would the output voltage be?
2. If the diode is reversed in clipper circuit, what would the output be like?
Electrical & Electronics Engineering, Amrita Vishwa Vidhyapeetham, Coimbatore
EE392 Electronic Circuits Lab
INFERENCE
RESULTS AND CONCLUSION
ASSESSMENT
Student Task
Max.Marks
Prelab simulation
20
Observation &
20
Inference
Viva-voce
10
Total
50
Electrical & Electronics Engineering, Amrita Vishwa Vidhyapeetham, Coimbatore
Graded Marks