Clamper Circuits using Diode

It is an arrangement of diode and capacitor which is used to shift the positive and negative peak of a signal at some desired dc level by not changing the shape of the signal.

Clamper Circuit Introduction

Clamper Circuit is divided into 3 Types as following:

  1. Positive Clamper Circuit
  2. Negative Clamper Circuit

1. Positive Clamper Circuit

In positive clamper circuit , the circuit is used to shift the input negative peak to zero level. This can be achieved and designed by diode , capacitor and resistor .

Circuit Diagram of positive clamper is shown below :

Positive Clamper Final

Initially in positive half cycle , Diode act like as an open circuit due to reverse biased condition and the capacitor will get charged but capacitor will not equal to peak voltage V  due to high RC time constant. So the output signal will remain same as an input signal. (So , we will not add this cycle in waveform.)

Open Circuit Positive Clamper

Now in negative half cycle ,polarity of signal will get reversed, Diode will get forward biased and act like as a closed and short circuit. So the capacitor will get charged to peak voltage V . So by using KVL, the output voltage is equal to Vin + V = 0V.(For , this negative half cycle).

Closed Circuit Clamper

So for next positive half cycle , diode act like as an open circuit and by using KVL , Vout = Vin + V=2V. (Here V is charged voltage by capacitor.) and for negative half cycle , it will remain as an open circuit due to reverse biased condition and Output signal is equal to (Vin + V).

Positive Clamper Final

2. Negative Clamper Circuit

In negative clamper circuit , the circuit is used to shift the input positive peak to zero level. This can be achieved and designed by diode , capacitor and resistor.

Circuit diagram of negative clamper circuit as shown below:

Negative Clamper Circuit Final Final

Initially in positive half cycle , Diode act like as an closed circuit so the capacitor will get charged to peak voltage V . By using KVL , output voltage is equal to Vin – V = 0.

now in negative half cycle , polarity of signal will get reversed, Diode will be reversed biased and act like as an open circuit. and the output voltage of circuit is equal to -Vin -V = -2V

Negative Clamper Circuit Calculation