Clipper Circuits Questions and Answers for Viva

Answer-1: In electronics, a clipper is a device designed to prevent the output of a circuit from exceeding a predetermined voltage level without distorting the remaining part of the applied waveform. Series clippers are mployed as noise limiters in FM transmitters by clipping excessive noise peaks above a specified level.

Answer-2: A clipping circuit consists of linear elements like resistors and non-linear elements like junction diodes or transistors. Thus a clipper circuit can remove certain portions of an arbitrary waveform near the positive or negative peaks. Clipping may be achieved either at one level or two levels Clipping Circuits are also called as Slicers, amplitude selectors or limiters.

Answer-3: one or two zener diodes are used to clip the voltage VIN. In the first circuit, the voltage is clipped to the reverse breakdown voltage of the zener diode. In the second, it is limited to the reverse breakdown voltage plus the voltage drop across one zener diode.

Answer-4: Practical clippers may be classified into two types: (a) Shunt Clippers, and (b) Series Clippers. The series configuration is defined as one where diode is in series with the load In a shunt clipper which uses a diode in conjunction with a resistor the diode forms a parallel path across the output. The network must have capacitor, a diode, and a resistive element, but it also employs an independent dc supply to introduce an additional shift.

Answer-5: It is used in television sets and FM receivers. It is also used for amplifier and different types of op-amps through which we can do some mathematical operations.

Answer-6: Depending on the orientation of the diode, the positive or negative region of the input signal is clipped off and accordingly the diode clippers may be positive or negative clippers.

Answer-7: Positive Clipper: The clipper which removes the positive half cycles of the input voltage is called the positive clipper. The positive series clipper circuit (that is, diode in series with the load). while the input is positive, diode D is reverse biased and so the output remains at zero that is, positive half cycle is clipped off. During the negative half cycle of the input, the diode is forward biased and so the negative half cycle appears across the output.

Answer-8: If the positive clipper circuit is reconnected with reversed polarity, the circuits will become for a negative clipper and the operation will be same.

Answer-9: When a portion of both positive and negative of each half cycle of the input voltage is to be clipped (or removed), combination clipper is employed.

Answer-10: In series clippers, when diode is in off position, there should be no transmission of input signal to output. But in case of high frequency signals transmission occurs through diode capacitance which is undesirable. This is the drawback of using diode as a series element in such clippers.