STYREKREDSLOEB TIL PLASMASKAERE- OG SVEJSEUDSTYR KONSTRUERET TIL AT ARBEJDE MED OVERFOERT BUE

摘要

Plasma arc torch for cutting or welding has a fixed electrode and nozzle movable axially into temporary contact therewith to strike the arc. Power is supplied by a transformer through a rectifier bridge, the nozzle being connected to one terminal of the latter through a resistor. A detector connected across the rectifier terminals senses the change from stand-by to normal operation when the power is switched on and enables the arc to be transferred to the work by switching in the ground connection between work and power terminal only after the arc has been struck.