초록 ▼

A power supply apparatus for welders includes an input-side AC-to-DC converter for converting an input commercial AC voltage into a DC voltage, which is, in turn, converted to a high-frequency voltage in an inverter. The high-frequency voltage is transformed to a high-frequency voltage having a desi

A power supply apparatus for welders includes an input-side AC-to-DC converter for converting an input commercial AC voltage into a DC voltage, which is, in turn, converted to a high-frequency voltage in an inverter. The high-frequency voltage is transformed to a high-frequency voltage having a desired magnitude in a transformer. The transformed high-frequency voltage is then converted back to a DC voltage in an output-side high-frequency-to-DC converter. The DC voltage is developed between output terminals of the power supply apparatus. A current detector detects the current flowing through the output terminals and develops a detected-current representative signal. A voltage detector detects the voltage between the output terminals and develops a detected-voltage representative signal. A CPU has three control modes and controls, in a first mode, the inverter in such a manner that the current representative signal becomes equal to a reference-current representative signal. In a second mode, the CPU activates and, then, deactivates a high-frequency generator, which provides a high-frequency voltage between the output terminals, and, thereafter, performs the first mode of control. In a third control mode, the CPU controls the inverter in such a manner that the voltage representative signal becomes equal to a reference-voltage representative signal and also controls a wire feeder for feeding a wire to be connected to one of the output terminals.

대표청구항 ▼

[ What is claimed is:] [1.] A power supply apparatus for use in welding, comprising:an input-side AC-to-DC converter for converting a commercial AC voltage into a DC voltage;a DC-to-high-frequency converter for converting the DC voltage developed by said input-side AC-to-DC converter to a high-frequ

[ What is claimed is:] [1.] A power supply apparatus for use in welding, comprising:an input-side AC-to-DC converter for converting a commercial AC voltage into a DC voltage;a DC-to-high-frequency converter for converting the DC voltage developed by said input-side AC-to-DC converter to a high-frequency voltage;a transformer for voltage-transforming the high-frequency voltage from said DC-to-high-frequency converter to a high-frequency voltage having a predetermined value;an output-side high-frequency-to-DC converter for converting the high-frequency voltage developed by said transformer to a DC voltage and applying the DC voltage between two output terminals adapted to be connected to a load;a current detector adapted to detect current flowing through said output terminals and to develop a current-representative signal representing the detected current;a voltage detector for detecting a voltage between said output terminals and developing a voltage-representative signal representing the detected voltage; anda controller selectively operable in first, second and third control modes, said controller being adapted to control, in said first control mode, said DC-to-high-frequency converter in such a manner that said current-representative signal becomes equal to a reference-current representative signal representing a reference current having a predetermined value, said controller, in said second control mode, being adapted to activate and then deactivate a high-frequency generator to be used to provide a high-frequency voltage between said output terminals and thereafter to control said DC-to-high-frequency converter in the same manner as in said first control mode, said controller, in said third control mode, being adapted to control said DC-to-high-frequency converter in such a manner that said voltage-representative signal becomes equal to a reference-voltage representative signal representing a reference voltage having a predetermined value and also control a wire feeder to be used to feed a wire to be connected to one of said output terminals.