Clamper Circuit and Types of Clamper Circuit

The clamping circuit or clamper circuit is an electronic circuit that shifts the DC level of a waveform. 

It is used in applications when control of the DC level is necessary.

 

Clamper circuits are used in 

video processing,

power supplies,

waveform shaping

 The Clamper Circuit:

This circuit has a combination of diodes, resistors, and capacitors arranged such that they add a dc level to the waveform or subtract a dc level from the waveform.

The capacitor, diode, and resistor are connected in parallel. 

The input signal is applied across the capacitor.

When the diode is forward-biased, it allows the current to flow through the capacitor, which charges the capacitor to a certain voltage level. 

This voltage is added to the input waveform, shifting it up or down.

The Positive Clamper

The positive clamper is a type of clamper circuit that shifts the input waveform upwards or above the 0 reference. 

In this circuit arrangement, the diode is forward-biased during the positive half-cycle of the input waveform, which allows the current to flow through the capacitor. 

Consequently, the capacitor charges to a voltage level which equals the peak value of the input waveform. 

During the negative half-cycle, the diode is reverse-biased, which disconnects the capacitor from the input waveform. 

Consequently, the waveform remains unchanged during the negative half-cycle.

The Negative Clamper

The negative clamper shifts the input waveform downwards (below reference).

Likewise to the positive clamper, the diode is forward-biased during the negative half-cycle of the input waveform and allows the current to flow through the capacitor. 

This charges the capacitor to a voltage level equal to the peak value of the input waveform but with an opposite polarity in comparison to a positive clamper.

During the positive half-cycle, the diode is reverse-biased, which disconnects the capacitor from the input waveform. 

As a result, the waveform remains unchanged during the positive half-cycle.

The Positive Clamper with Positive Bias

The positive clamper with positive bias is a positive clamper circuit with additional DC bias voltage is added to the capacitor. 

This bias voltage is connected such that it adds to the charging voltage of the capacitor during the positive half-cycle of the input waveform. 

Consequently, the output waveform is shifted upwards by the addition of both the bias voltage and the capacitor voltage during the positive half-cycle.

 The positive clamper with negative bias

This circuit is positive clamper circuit where the DC bias voltage is connected such that it subtracts from the charging voltage of the capacitor during the positive half-cycle of the input waveform. 

This reduces the output waveform by the bias voltage during the positive half-cycle.

Negative Clamper with Positive Bias

The negative clamper with positive bias is a variation of the negative clamper circuit where the DC bias voltage is connected in such a way that it adds to the charging voltage of the capacitor during the negative half-cycle of the input waveform. 

Consequently, the output waveform is shifted downwards, resulting in a lower waveform during the negative half-cycle.

Negative Clamper with Negative Bias

The negative clamper with negative bias is a modification of the negative clamper circuit where the DC bias voltage is connected in such a way that it subtracts from the charging voltage of the capacitor during the negative half-cycle of the input waveform. 

This reduces the output waveform further during the negative half-cycle, resulting in a more negative waveform.

Input Signal, Positive Clamping, and Biased Positive Clamping

Input Signal, Negative Clamping, and Biased Negative Clamping

 In Summary,