11.11 : クリッパ回路

A clipper circuit is a wave-shaping tool that uses diodes to modify waveforms.

These circuits are common in TVs, radar transmitters, and receivers.

Consider a dual-clipper circuit consisting of two ideal diodes, each connected to a biasing battery, and a resistor.

During the positive half-cycle of the input AC signal, diode D₁ is forward-biased by the input signal and reverse-biased by the biasing battery. In contrast, diode D₂ is reverse-biased by both.

If the input voltage is less than the biasing voltage, diode D₁ acts as an open switch, resulting in the output reflecting the same applied voltage.

However, when the input voltage exceeds the biasing voltage, diode D₁ becomes forward-biased, blocking the input voltage and leaving no signal at the output.

For the negative half-cycle, a similar process occurs with diode D₂ clipping the signal and the output voltage being limited by D₂'s biasing voltage.

The resistance value is meticulously selected to balance adequate forward diode current and minimal voltage drop from the reverse diode current.