Rectifier Circuit

Half-wave rectifier

In the elementary half wave rectifier circuit, the load is shown as a resistor but in practice it will be a piece of electronic equipment.  During half cycles of alternating input voltage diode D conducts, creating a pulse of current.  This produces a voltage across R of almost the same value as the peak input voltage, if the forward resistance of the diode is small compared with the value of R.

During the negative half cycles of input voltage, the diode is cut off so there is little or no current in the circuit and therefore the voltage across R is zero.

Centre-tap full wave rectifier

With a Full Wave rectifier each half cycle of input produce current pulses.

The circuit have two diodes D₁ and D₂ and a transformer with centre tapped secondary winding.  Suppose that at the peak of the first half cycle of input, the voltage induced in winding AOB is 10v.  If we take the centre tap 0 as the reference point at OV, then when A is at +5v, B will be at –5v.  D1 then conducts causing a current pulse to flow in the direction;During the other half of the first cycle, B becomes positive to O (thus A is negative with respect to O).  Diode D₂ therefore conducts giving current in the circuit .D₁ is now cut off.