PULSE ARC WELDING METHOD AND DEVICE IN WHICH PULSE CURRENT AND BACKGROUND CURRENT HAVE A CONSTANT CURRENT CHARACTERISTIC

A pulse arc welding device includes a power source which produces a background current and pulse current imposed on it. A voltage drop across the arc is measured and when such a voltage drop deviates from a predetermined level, either one of background current, frequency of the pulse current and pulse duration of the pulse current is controlled to maintain the voltage drop across the arc constant.