| 摘要 |
<P>PROBLEM TO BE SOLVED: To solve the problem that currents flowing in elements constituting an inverter circuit are in a poor balance to cause a big variation in heat loss among the elements. <P>SOLUTION: The welding power device for arc working an inverter circuit forming a bridge from the first element to the forth element for changing direct current voltage to high-frequency alternating current voltage, and a phase shift control circuit provided with a phase sifting term by the first conduction term, the circulation term, the second conduction term, and the second circulation term and controlling phase shift by feedback control, for outputting direct current voltage suitable for arc working by changing the high frequency alternating current voltage to it. During the n-th phase shifting term, the above phase sifting control is done, and during the n+1-th phase sifting term, the first and the second circulation terms are exchanged and the phase sifting control is done, and after that, the n-th and the n+1st phase sifting controls are alternately repeated. <P>COPYRIGHT: (C)2004,JPO |
