| 摘要 |
A welding current source for alternating-current arc welding with a controllable inverter (2), the output transformer (5) of which has two separate secondary windings (6, 7), each of which is connected through its welding circuit to a welding location (14, 15). An electronic coupling element unit (12, 13) and an inductor winding (18, 19) is connected into each welding circuit. Both inductor windings are arranged on a common core (20). Immediately before the change in polarity, the inverter (2) is operated by a controller (4) which controls the welding current to a value which, at the instant of changing polarity, is equal to or slightly higher than the minimum current which reliably re-strikes the arc after the change in polarity. <IMAGE> |
