Patent ID: 9494956
Filing Date: 2016-11-15
CPC Classification: G05F,H02J,H02M,Y02T

Claim Text:
1. A power supply device, comprising: a magneto AC generator comprising: a rotor including a permanent magnet; and a stator configured to generate an AC current in a stator winding by rotation of the rotor; a rectifier configured to rectify the AC current generated by the magneto AC generator into a DC current; an electrical load to be supplied with electric power generated by the magneto AC generator; a DC voltage transformer having a variable transformation ratio, which is configured to transform an output voltage of the rectifier into an input voltage between input terminals of the electrical load; a voltage/current detector configured to detect an output voltage signal and an output current signal of the DC voltage transformer; and a voltage controller configured to control the transformation ratio of the DC voltage transformer in a stepless manner within a set range based on an operating state signal including an rpm variation signal relating to the rotation of the rotor, the output voltage signal, and the output current signal, wherein the voltage controller is configured to: control, in accordance with the output voltage signal and the output current signal, output power of the rectifier to a voltage lower than a voltage by which an amount of generated power of the magneto AC generator becomes maximum; control the transformation ratio in accordance with the output voltage signal and the output current signal so as to improve power generation efficiency of the magneto AC generator one of when the rpm variation signal indicates an decelerating state and when the rpm variation signal indicates that a variation in rpm indicates a value smaller than a predetermined constant; and control the transformation ratio so as to decrease the output power of the rectifier when the rpm variation signal indicates an accelerating state.