The central tapping of the transformer in centre tapped full wave rectifier is used:

Concept:

• The central tapping of the transformer in a center-tapped full wave rectifier is used to make both the diodes conduct during alternate half cycles.
• In a center-tapped full-wave rectifier, the center-tap is used to divide the transformer secondary voltage into two halves.
• During one-half cycle, one diode conducts, while during the other half cycle, the other diode conducts.
• This allows the load current to flow for the entire cycle, which is why it's called a full-wave rectifier.
• The center tap effectively splits the total secondary voltage into two equal voltages, allowing for the rectification of both halves of the AC waveform.

Additional Information

Half wave rectifier

• A half-wave rectifier converts an AC signal to DC by passing either the negative or positive half-cycle of the waveform and blocking the other. Half-wave rectifiers can be easily constructed using only one diode, but are less efficient than full-wave rectifiers.
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Full wave Rectifier

• Full-Wave Rectifiers are rectifier electric circuits that convert both half cycles of an alternating current (AC) into direct current (DC)

Bridge Rectifier

• A bridge rectifier is an alternative to a full wave rectifier.