Patent ID: 6498320
Filing Date: 2002-12-24
Classification: B23K

Abstract:
A power supply apparatus for arc-utilizing apparatuses, comprising:a power supply terminal to which one of plural commercial AC power supplies providing different AC voltages is adapted to be connected, said plural commercial AC power supplies belonging to either first or second group, a magnitude of the AC voltages provided by the AC power supplies of said first group being about twice that of the AC voltages provided by the AC power supplies of said second group; a rectifier for rectifying the AC voltage provided by the commercial AC power supply connected to said power supply terminal and developing a rectified voltage between two rectifier output terminals; two voltage-boosting converters; a switching unit for selectively connecting said two voltage-boosting converters in series and in parallel with each other between said two rectifier output terminals; two DC-to-high-frequency converters connected in output sides of and in association with said respective voltage-boosting converters, for converting DC voltages inputted thereto from the associated ones of said voltage-boosting converters into high-frequency voltages; a voltage-transformer having a primary side receiving the high-frequency voltages from said DC-to-high-frequency converters; a high-frequency-to-DC converter for converting a high-frequency voltage induced in a secondary side of said voltage-transformer into a DC voltage, said DC voltage being developed between two load output terminals; and a switching control unit for controlling said switching unit in such a manner that said two voltage-boosting converters can be connected in series between said rectifier output terminals when the commercial AC power supply connected to said power supply terminal belongs to said first group, said switching control unit controlling said switching unit in such a manner that said two voltage-boosting converters can be connected in parallel between said rectifier output terminals when the commercial AC power supply connected to said power supply terminal belongs to said second group.