PULSE ARC WELDING POWER SUPPLY

PROBLEM TO BE SOLVED: To make it pssible to display a voltage proportional to an arc length on a voltmeter of a welding power source even when unusual voltage is superposed in a pulse arc welding power source which uses only inert gas for shield gas, supplies the welding current Iw composed of peak current and base current, detects the welding voltage Vw between a consumable electrode 1 and a base material 2, calculates the welding voltage limiting value Vft by limiting the detected welding voltage Vd by the predetermined variation range Vc ± ΔVc from the reference voltage waveform Vc of the pulse waveform, and controls the output of the welding power source so that the average welding voltage limiting value Vfa obtained by averaging the welding voltage limiting value Vft is approximately equal to the predetermined voltage set value Vs. SOLUTION: In the pulse arc welding power source, the welding voltage limiting value Vft or the average welding voltage limiting value Vfa is the input signal to an interface terminal to a voltmeter VM and/or an external instrument arranged on the welding power source in place of the detected welding voltage value Vd. COPYRIGHT: (C)2006,JPO&NCIPI