Abstract: An inverter power supply system includes a half-bridge inverter circuit which includes a first switching element, a second switching element, a first auxiliary capacitor and a second auxiliary capacitor for converting a DC voltage from a DC power supply circuit to an AC voltage. An output control circuit outputs a first output control signal and a second output control signal with a phase difference of a half cycle to control the inverter circuit. An inverter driving circuit turns on the first (or second) switching element when the first (or second) output control signal turns ON while turning off the first (or second) switching element upon lapse of a first (or second) delay time for allowing the first (or second) auxiliary capacitor to discharge to a predetermined level after the first (or second) output control signal turns OFF.

Abstract: An inverter power supply system includes a half-bridge inverter circuit which includes a first switching element, a second switching element, a first auxiliary capacitor and a second auxiliary capacitor for converting a DC voltage from a DC power supply circuit to an AC voltage. An output control circuit outputs a first output control signal and a second output control signal with a phase difference of a half cycle to control the inverter circuit. An inverter driving circuit turns on the first (or second) switching element when the first (or second) output control signal turns ON while turning off the first (or second) switching element upon lapse of a first (or second) delay time for allowing the first (or second) auxiliary capacitor to discharge to a predetermined level after the first (or second) output control signal turns OFF.

Abstract: There is disclosed a power source apparatus for an alternating-current arc welding. In the power source apparatus, a reference signal generator periodically generates a reference signal having a predetermined waveform, and a direct-current power source outputs a current periodically changing in response to the reference signal, the outputted current having a waveform corresponding to that of the reference signal. Thereafter, a switching circuit supplies an alternating-current welding current to a welding load so as to sequentially change the polarity of the welding current from a straight polarity to a reverse polarity and from the reverse polarity to the straight polarity in synchronization with the reference signal by switching the current outputted from the power source in response to the reference signal.

Abstract: A power supply for arc processing which can be used with a commercial AC power supplying either a high or low voltage, with the low and high voltages having a ratio of 1:2. The power supply includes two or three rectifying circuits connected in parallel, each of which comprises three series diodes, with a first series connection point of each series connected diodes being connected to one of the input terminals (phases) of the commercial power supply. The power supply further includes two or three voltage change over circuits, comprising a capacitor and a voltae change-over switch, closed at a low voltage input, connected between a second connection point of its corresponding rectifying circuit and the first connection point of another rectifying circuit. An inverter circuit for inverse conversion is connected in parallel between the terminals of the three rectifying circuits.