A power-factor improved AC to DC converter

Abstract

A new AC-to-DC converter is described which improves the power factor of the AC input line. The converter is composed of a forward converter and a flyback-derived voltage-commutated circuit. When the switching transistor is on, the induced voltage across the transformer is applied to the inductor of the feedback circuit, and energy is stored. When the input voltage is high, the voltage across the capacitor of the feedback circuit does not commutate to the input, while when the input voltage is low, the voltage across the capacitor of the feedback circuit is commutated to the input side capacitor. Therefore, the time duration of the input current is longer than the conventional one, and the power factor is improved. Analysis of the converter circuit and experimental results are presented.<>