| 摘要 |
PROBLEM TO BE SOLVED: To provide an arc welding machine in which an exciter rush current value encountered in closing a power source is reduced. SOLUTION: The arc welding machine comprises: a target phase angle setting circuit PE outputting the operation value of (90°-Δα) or (270°-Δα) used as a previously set target phase angleΔQ and obtained from operation delay timeΔα, from inputting an opening and closing signal to a main circuit switch MS until closing the opening and closing contact of the main circuit switch MS; and a phase discriminant circuit PD outputting a phase discriminant signal Pd when the phase angle of a commercial AC power source coincides with the target phase angleΔQ after closing a control switch SW1. The main circuit switch MS is closed at a phase angle 90°or 270°of the commercial AC power source by means of the phase discriminant signal Pd. COPYRIGHT: (C)2004,JPO
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