rectifier is a device which converts AC voltage to pulsating DC voltage using one or more diode diode conducts only in unit direction that is forward bias condition practically it does not conduct when it is in Reverse bias does alternating voltage is applied across PN junction diode during positive half cycle the diode will be in forward bias condition and it successfully conduct while the negative half cycle it will be in a reverse bias and will not conduct at all there are three types of rectifiers first is half wave rectifier second is full wave rectifier it has two types one is with using two diodes and Centre tap Transformer and another is bridge wave rectifier