Patent ID: 8541989

Claim:
A power supply apparatus comprising: an AC generator including an AC generating section, and a rectifier for rectifying an AC voltage generated in the AC generating section into a DC voltage, and outputting the DC voltage; and a DC/DC converter for converting the DC voltage outputted by the rectifier into a DC voltage having a voltage value different from that of the DC voltage outputted by the rectifier, and outputting the DC voltage that has been converted, wherein the DC/DC converter performs a step-down operation for stepping down the output voltage of the AC generator and performs a shorting operation for shorting the output of the AC generator and the output of the DC/DC converter, wherein, the step-down operation and the shorting operation of the DC/DC converter are switched in accordance with the rotation speed of the AC generating section and the amount of power supply to an electrical load connected to the DC/DC converter.