Power supply apparatus and image forming apparatus using the same

摘要

A power supply apparatus includes a boost circuit and a switch circuit. The boost circuit has rectifying elements and charge storage elements associated with the rectifying elements, and outputs a boosted voltage by sequentially cumulating charges in the charge storage elements in accordance with an AC input signal. The switch circuit switches a polarity of boosting in cumulating the charges in the charge storage elements. The boost circuit includes a circuit part that supplies charges to be sequentially cumulated in positive and negative directions in accordance with the AC input signal.