| 摘要 |
A control system is interposed between the input terminal (14) and the output terminal (16) of a welding machine (10). An electrical conductor (18) is connected to the input terminal. A ground conductor (20) extends out from the housing (12) of the welding machine (10). An electrode conductor (24) extends from the output terminal (16) to an electrode holding device (26). An electrode (28) is held by the electrode holder (26). The control circuit includes means for connecting welding voltage to the electrode holding device (26) and the electrode (28) when the electrode (28) is connected to a grounded workpiece (50). A control circuit also connects the electrode holding device (26) and the electrode (28) to a lower, safe voltage, when the electrode (28) is disconnected from the grounded workpiece (50). As a result, the welder is protected from electrical shocks when the electrode (28) is disconnected from the grounded workpiece (50). The control circuit is characterized by one, two, three or more SCRs.
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