Patent ID: 6069811
Filing Date: 2000-05-30
Classification: H02H,H02M

Abstract:
A DC power supply apparatus comprising:a rectifier circuit for rectifying an input commercial AC voltage;a smoothing capacitor for smoothing a rectified output voltage from said rectifier circuit;a DC-to-high-frequency converter circuit for converting a smoothed DC voltage from said smoothing capacitor into a high-frequency voltage;a transformer for voltage-transforming the high-frequency voltage supplied from said DC-to-high-frequency converter circuit;a high-frequency-to-DC converter circuit for converting a voltage-transformed, high-frequency voltage supplied from said transformer into a DC voltage;a pre-charging circuit for pre-charging, when said input commercial AC voltage is applied to said DC power supply apparatus, said smoothing capacitor from the input commercial AC voltage; andan overvoltage protection circuit for rendering said pre-charging circuit and said rectifier circuit inoperative when said input commercial AC voltage is a voltage having a magnitude larger than a prescribed value.