a power inverter including a switch circuit for transferring energy received from an input DC voltage and a main pulse width modulator coupled to the switch circuit for generating control pulse signals to drive the switch circuit;

a power transformer having a primary winding and a secondary winding, wherein the primary winding is coupled to the power inverter for receiving the energy therefrom and transferring the energy across the secondary winding according to the open and close of the switch circuit;

a rectifier transistor circuit coupled to the secondary winding for rectifying the energy transferred from the secondary winding into a rectified DC voltage and comprising a first rectifier transistor and a second rectifier transistor;

an output filter coupled to the rectifier transistor circuit for smoothing the rectified DC voltage to generate a regulated DC voltage;

a plurality of post voltage regulators tapped to the secondary winding for providing a plurality of regulated DC voltages;

a pair of series capacitor coupled across the secondary winding and the first rectifier transistor for providing control pulse signals to drive the first rectifier transistor; and

an inverter connecting the second rectifier transistor and the main pulse width modulator of the power inverter to drive the second rectifier transistor by inverse version of the control pulse signals of the main pulse width modulator.