A high-power-factor buck converter

A high-power-factor buck converter is proposed. The converter is composed of rectifier diodes, a small input capacitor, and a buck converter. It supplies low output voltages and uses low voltage semiconductor devices and ceramic capacitors. Two operation modes exist in the converter: discontinuous and continuous inductor current modes. Analysis and experimentation show that the converter's power factor is over 0.9 in discontinuous mode by constant duty ratio operation. It is clarified that the power factor decreases to about 0.7 in continuous mode by constant duty ratio operation, and it can be improved to over 0.9 by a new input current control system.<
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