Clippers and clampers

The clippers and clampers are simple diode circuits .

Clipper:

In the clipper circuit a dc source is connected in series or in parallel to the diode.As an ac input is given to the circuit,the input passes only if the diode is forward biased and the applied voltage is greater than the dc supply voltage and the dc supply is such that the voltage drop is in the direction of current flow from the ac source.For voltages of ac input less than the difference between ac input and dc input the diode is in reverse bias.Hence the diode acts as an open circuit.Thus a part of the output is clipped.

In the positive clipper the positive part of the input is clipped and in negative clipper negative part of the input is clipped.

Clampers:

Clampers are diode circuits which cause shifting of the input signal by some distance.In this circuit a capacitance is connected in series with the ac input and a diode is connected in parallel.Till the capacitance acquires potential the ac input does not pass to the diode.Thus only when the capacitance is charged the diode starts conducting.

 The capacitor must be chosen such that, during the conduction of the diode, the capacitor must be sufficient to charge quickly and during the nonconducting period of diode, the capacitor should not discharge drastically. The clampers are classified as positive and negative clampers based on the clamping method.

Negative clamper:Above figure shows a negative clamper.

Above figure shows a positive clamper.