11.8 : Half wave rectifier

A half-wave rectifier is a fundamental circuit in electronics, designed to convert alternating current (AC) voltage into a unidirectional voltage. It utilizes the simplest form of diode rectification, where the circuit comprises a single diode in series with a load resistor and an AC power source.

The operation of a half-wave rectifier is based on the principle that diodes permit current flow in only one direction. During the positive half-cycles of the AC input, the diode is forward-biased as the input voltage exceeds the diode's threshold. Consequently, current flows through the circuit, and an output voltage develops across the load resistor. This output voltage is the input voltage minus the forward voltage drop of the diode.

On the flip side, during the negative half-cycles, the diode is reverse-biased. The input voltage doesn't suffice to overcome the diode's inherent potential barrier, rendering the diode non-conductive. Hence, there's no current flow, and the output voltage drops to zero. This rectification results in a pulsating direct current (DC) that flows only during the positive half-cycles of the input AC signal.

A crucial parameter for diodes in rectifier circuits is the peak inverse voltage (PIV). This is the maximum voltage the diode can withstand in reverse-biased conditions without undergoing breakdown. In a half-wave rectifier, the PIV is essentially the peak value of the input AC voltage but with an opposite polarity. It's vital that the chosen diode can handle the expected PIV to prevent damage and ensure the circuit's longevity.