INTRODUCTION
Conventional AC-DC converters usually employ a full wave rectifier bridge with a simple capacitor filter to draw power from the AC line. This "bulk" capacitor must be big enough to supply the total power during most of each half-cycle, while instantaneous line voltage is below the DC rectified voltage. Consequentely, the line current waveform is a narrow pulse, and the power factor is poor (0.5-0.6) due to the high harmonic distortion of the current waveform.