A boost-input self-driven active clamp ZVS converter

This paper proposes a boost-input self-driven active clamp ZVS converter. The converter used the auxiliary winding of the transformer to drive the active clamp switch and to achieve asymmetrical duty control. The operation principle was presented and experimental results were used to verify the theoretical predictions. A 300W (15V/20A) prototype converter that only exhibited 2-turn winding number in the auxiliary winding was sufficient to drive the active clamp switch on the input voltage of 80V. Finally, the maximum efficiency of 91.2% was achieved for the prototype converter.