LAB SHEET EXPERIMENT NO: 03 EEE 224

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-

V

-V

t

Vo

(c) Output voltage(b) Input voltage

V

-V

t

Vi

(a) Circuit diagram

-

Vi R Vo

+ +

STAMFORD UNIVERSITY OF BANGLADESH DEPARTMENT OF ELECTRICAL & ELECTRONIC ENGINEERING

COURSE NO: EEE224, COURSE TITLE: ELECTRONIC LAB

Experiment No: 03 Name of the Experiment: Study of clipper, clamper and limiter circuit.

1. OBJECTIVE To study the application of diodes in different clipper, clamper and limiter circuits. 2. REQUIRED EQUIPMENTS

3. THEORY a. Clipper

Clipper circuits have the ability to “clip” off a portion of the input signal without distorting the remaining part of the alternating waveform. The half wave rectifier of the previous experiment is an example of the simplest from of diode clipper. Depending on the orientation of thy diode, the positive or negative region of the input signal is “clipped” off. There are two general categories of clippers: series and parallel. The series configuration is defined as one where the diode is in series with the load, while the parallel variety has the diode in branch parallel to the load. The simple clipper circuit diagram and its input and output wave shapes are shown Figure 1.

Figure 1: Simple clipper circuit

Diode 1N4003 four pieces Zener diode 5V two pieces Resistor 10K one piece Capacitor 10µF one piece Signal generator one piece Oscilloscope one piece Chords and wire As necessary

LAB SHEET EXPERIMENT NO: 03 EEE 224

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ViVo

+

-

+

-

C

R t

V

-V

Vi

0 T /2 T

V

-V

t

Vo

0 T /2 T

(a) Circuit diagram (b) Input voltage (c) Output voltage

b. Clamper The clamper circuit is one that will “clamp” a signal to a different dc level. The network must have a capacitor, a diode and a resistive element, but it can also employ an independent dc supply to introduce an additional shift. The magnitude of R and C must be chosen so that the voltage across the capacitor does not discharge significantly during the interval the interval the diode is non-conducting. There is an important point to note that, the total swing of the output is equal to the total swing of input signal. The simple clamper circuit diagram and its input and output wave shapes are shown Figure 2.

Figure 2: Simple clamper circuit

c. Limiter The operation of a limiter circuit is almost same that of a clipper circuit. The difference between these two circuits (limiter and clipper) is that, the clipper “clips” off a portion of input signal whereas the limiter sets a “limit” in amplitude of an input signal. A simple clipper circuit in the Figure 1 is said to be as a limiter circuit in this sense that, it limits the input signal in the range of 0V to positive peak input voltage. The input and output voltage of a limiter circuit can be visualized in Figure 3.

Figure 3: Input and output voltage of a limiter circuit

Limiter Circuit

0 t

Vo

0 t

Vi

(a) Input voltage (b) Output voltage

LAB SHEET EXPERIMENT NO: 03 EEE 224

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4. CIRCUIT DIAGRAM FOR EXPERIMENT

Figure 4: Clipper circuit

Figure 5: Clamper circuit

Figure 6: Limiter circuit using zener diode

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5. PROCEDURE A. Construct the circuit as shown in Figure 4. Observe the input and output wave

shapes. B. Construct the circuit as shown in Figure 5. Observe the input and output wave

shapes. C. Construct the circuit as shown in Figure 6. Observe the input and output wave

shapes.

6. REPORT A. Draw the input and output wave shapes observed in a clipper circuit. B. What will affect the 5V DC source if it is connected in reverse that of shown in

Figure 4. Explain the operation of the circuit in that case and draw the ideal output wave shape.

C. Draw the input and output wave shapes observed in a clamper circuit and describe its operation.

D. Draw the input and output wave shapes observed in a clamper circuit. E. Design a circuit in which the input voltage Vi =5 sin ωt and the output should be

limited between + 2.5 V and – 3.5 V. Assume that the diodes are ideal.

Prepared by, KURRATUL AIN Lecturer, Deptt. Of EEE, Stamford University Bangladesh Date: 06.02.10 Acknowledgement, SHIHANUR RAHMAN AND AHSAN HABIB Lecturer, Deptt. Of EEE, Stamford University Bangladesh