11.10 : 桥式整流器

The bridge rectifier, vital for converting AC to DC, consists of four diodes arranged in a bridge configuration.

This arrangement enables it to rectify both the positive and negative halves of the waveform.

During the positive half-cycles of the input voltage, the bridge rectifier conducts current through diodes D₁ and D₂ and resistor R, while diodes D₃ and D₄ are reverse-biased.

Conversely, during negative half-cycles, the secondary voltage is negative, and current flows through diodes D₃ and D₄ and resistor R, with diodes D₁ and D₂ reverse biased.

Despite the changing cycles, the direction of the current flow remains consistent, resulting in a consistently positive pulsating DC output voltage.

The peak inverse voltage is determined during positive half-cycles and is roughly half the value for a full-wave rectifier with a center-tapped transformer.

The bridge rectifier requires fewer turns for the transformer's secondary winding, rendering it more efficient and compact.

The bridge rectifier's efficiency can be enhanced by using Schottky diodes or by incorporating a capacitor filter, which reduces losses and improves the quality of the DC output.