Patent ID: 6154376
Filing Date: 2000-11-28
Classification: H02M,Y02B

Abstract:
A high-frequency, single-ended, low-loss, high power density power converter, comprising:two input terminals for receiving voltage input;a transistor having a parasitic capacitance;a low-leakage inductance transformer for coupling power to an output, said transformer having a leakage inductance of no more than 1 uH so that said leakage inductance has a negligible effect on resonance;a dedicated inductor connected in series with said transformer primary;wherein said inductor, said transformer primary and said transistor are all connected in series across said two input terminals, said inductor and the inherent transistor capacitance thus together forming a resonant energy storage tank on the transformer primary side of the power converter for shifting the voltage input into a sinusoidal waveform, and for transferring power stored in said transistor by reason of the inherent capacitance of said transistor;wherein said transformer has a magnetizing inductance at least one hundred times greater than the inductance of said dedicated inductor, said transformer thus having a large impedance which causes it to act as an open circuit and thus have a negligible effect on resonance; andmeans for switching the transistor on and off at the resonant frequency of said resonant energy storage tank to provide a sinusoidal output current pulse to the transformer primary at the transistor switching rate and to utilize energy stored in the inherent transistor capacitance.