Method of controlling the AC pulsed arc welding and welding power supply apparatus therefor

摘要

An consumable electrode AC pulsed arc welding is performed by repeatedly executing a cycle of supplying a peak current Ip in an electrode positive polarity, then supplying an electrode negative current Ien in an electrode negative polarity and finally supplying a base current Ib in the electrode positive polarity. During a base current supply time, the rate of increase dVb/dt of the base voltage Vb is detected. Should the base voltage increase rate dVb/dt detected be larger than a predetermined determining value &Dgr;Vu, it means that the arc interruption is likely to occur and, therefore, since that timing, the peak current Ip for the subsequent cycle is supplied to thereby prevent the arc interruption from occurring.