11.9 : 全波整流器

Consider a full-wave rectifier circuit comprising a center-tapped transformer, two diodes in a center-tapped configuration, and a load resistor.

The secondary winding of the transformer supplies two equal input voltages with opposite polarities across the two halves of the secondary winding.

During the positive half-cycles of the input signal, when the voltage exceeds or equals the diode's forward voltage drop, diode D1 conducts while D2 is reverse-biased. The output waveform resembles that of a half-wave rectifier.

Conversely, during the negative half-cycle, when the input voltage is lower than the diode's forward voltage drop, diode D1 is cut off while D2 conducts. Again, the output waveform mirrors that of a half-wave rectifier.

The current through the resistor consistently flows in the same direction, resulting in a unipolar output.

The increased rectification efficiency of a full wave rectifier enables its use in power supplies, battery chargers, audio amplifiers, and signal processing.

The peak inverse voltage is twice the peak input voltage minus the diode forward voltage drop, which is approximately twice that of the half-wave rectifier case.