Abstract: A rectifier of a power supply comprises a delay unit at a front end of a circuit for delaying a transient variation of a power current and then delaying the current to a rectifying end; a driving unit coupling to the delay unit by two inductors for adding an inducting voltage to a voltage of a switch unit at an input end for being converting as a driving voltage and for emitting a state of the driving unit based on a waveform of the driving voltage; and the switch unit being connected to the driving unit for receiving the state of the driving unit and for conducting or cutting-of the power current so that the operation of the switch unit is synchronous with the waveform of the power current.