WELDING DEVICE Russian patent published in 1998 - IPC

FIELD: mechanical engineering; welding. SUBSTANCE: proposed device consists of two inversely parallel thyristors with control circuit, thyristor cutoff capacitor with discharge circuit, and choke. Device operates so that thyristors, having been turned into conduction state are immediately cut off by back voltage from cutoff capacitor which is discharge to its discharge circuit after a lamps of minimum time sufficient for reliable locking of thyristors. This provides impulse operation of device until resistance of arc space drops below critical value. Then welding arc is started. EFFECT: provision of stability of arc burning at welding by low currents, reduced mass and cost of device, provision of safe operation under any operating conditions at correct connection of device to supply mains. 4 dwg