Abstract
A simple single-switch single-stage AC/DC converter based on the flyback topology with the high power factor correction, high efficiency and small size is proposed and implemented. It complies with IEC 61000-3-2 for low frequency harmonics under a power range (20-50W) at 110VAC input. The proposed converter introduces the auxiliary winding of the transformer to replace the bulk inductor of the conventional converter topologies. The voltage of the bulk capacitor is (1) clamped under the rectified line voltage and (2) not influenced by the output load. The efficiency reaches 89∼90% and the power factor is between 0.94 and 0.95.