A full wave rectifier is used to convert the AC signal to DC. In this circuit a bridge is used for this purpose which is in the form of 4 diodes connected as shown in the circuit. Each half cycle two diodes are forward biased and cause current conduction while the other two are reverse biased and have to stand a PIV (Peak Inverse Voltage) equal to the maximum input voltage. However, the output signal is only unidirectional with frequency equal to twice that of the input signal.
