Output voltage monitoring method of arc welding power supply and arc welding power supply

摘要

PROBLEM TO BE SOLVED: To provide an arc-welding power supply capable of monitoring output voltage properly even when a current flows into from other electrode during welding procedure by plural electrodes.SOLUTION: Threshold voltage used by a voltage monitor part 19f of a control circuit 19 is set based on output voltage E of a rectifier circuit 18 which varies as output voltage (arc voltage Vd) of a power supply 15. Thereby, when welding procedure by plural electrodes is performed with weldment machines 11, 21, even if current flows into an electrode 13 of a first weldment machine 11 from an electrode 23 of a second weldment machine 21, resulting in reduction of the output voltage (arc voltage Vd) of the power supply 15, monitoring of output voltage is performed properly.