Centre tapped full –wave rectifier

·         The circuit diagram of a center tapped full wave rectifier is shown in fig. 2.6 above. It employs two diodes and a center tap transformer.  The a.c. signal to be rectified is applied to the primary of the transformer and the d.c. output is taken across the load R_L.

·         During the +ve half-cycle end X is +ve and end Y is –ve this makes diode D₁ forward biased and thus a current i₁ flows through it and load resistor R_L.Diode D₂  is reverse biased and the current i₂ is zero.

• During the –ve half-cycle end Y is +Ve and end X is –Ve. Now diode D₂ is forward biased and thus a current i₂ flows through it and load resistor R_L. Diode D₁ is reversed and the current i₁ = 0.

Disadvantages

• Since, each diode uses only one-half of the transformer secondary voltage the d.c. output is comparatively small.
• It is difficult to locate the center-tap on secondary winding of the transformer.
• The diodes used must have high Peak-inverse voltage.