Full-Wave Rectification

FULL – WAVE RECTIFIER

Is a rectifier that yields d.c output during both the positive and negative half – cycles of the a.c input.

TYPES OF FULL-WAVE RECTIFIER

1. Bridge rectifier
2. Centre – tapped rectifier

BRIDGE RECTIFIER

Is a rectifier that use four diodes I series – parallel to produce full wave rectification.

During the positive half cycle, P become positive and Q become negative. This makes D₁, and D₂ forward biased while D₃ and D₄ reverse biased. Therefore, D₁ and D₂ conducts and hence current flows through load resister (R_L).

During the negative half – cycle, P becomes negative and Q becomes positive. This makes D₃ and D₄ forward biased while D₁ and D₂ reversed biased. Therefore, D₃ and D₄ conducts and hence current flows through load resistor (R_L)

CENTRE – TAPPED RECTIFIER

Is the rectifier that uses the center – tap of a transformer to produce full wave rectification. Centre-tapped rectifier uses two diodes D₁ and D₂ as shown.

OPERATION

During the positive half-cycle of secondary voltage, the end A of the secondary winding become positive and B become negative. This makes the D₁ forward bias and D₂ reverse biased, hence D₁ conducts and D₂ does not. The current flow through D_1, load   resistor (R_L) and the upper half of secondary winding

During the negative half-cycle of secondary voltage, the end A of the secondary winding become negative and B become positive. This makes the D₂ forward bias and D₁ reverse biased, hence D₂ conducts and D₁ does not. The current flow through D_2, load   resistor (R_L) and the lower half of secondary winding