摘要 |
The circuit is designed to protect plasma-arc welding or cutting equipment wired for transferred or non-transferred arc operation, using a torch of which the electrode is connected to the negative terminal of the power source and the nozzle to the positive; the arc can be transferred by wiring the work to the positive terminal also. With voltage between at least two of the three connected parts (electrode, nozzle and work) constantly monitored, filtered, and measured against a set point by a comparator of which the output operates a switch controlling the power supply to the equipment, the power source can be deactivated immediately in the event that the monitored voltage registers less than the set point.
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