Control circuit in plasma arc cutting and welding equipment.

摘要

The circuit disclosed comprises a transformer (T1) and a rectifier (T3), and is used in conjunction with a torch (T5) the electrode (a) of which is wired to one of the output terminals (31) of the rectifier; the nozzle (b) is connected to the remaining terminal (32) by way of a resistor (T10). A comparator (T8) monitors passage of the power stage from stand-by to normal non-transferred arc operation, and triggers switch-in of the ground cable by way of which the work (T6) is connected to the relative terminal (32) of the rectifier, only after an arc has first been struck between the electrode and the nozzle.