METHOD OF AND DEVICE FOR CONTROLLING WELDING CURRENT Russian patent published in 1997 - IPC

FIELD: semiautomatic gas shielded welding. SUBSTANCE: welding circuit is supplied by DC current source, arc is stricken and welding current is passed through choke. Welding current is compared with preset current level and when current has risen to preset value, supply source is switched off. Source is switched on after striking the arc when current value decreases. Novelty is that when supply source is switched on, welding current is passed through one more choke and when supply source is switched off currents of all chokes are summed up and summary current is passed through welding circuit. Supply source is switched on when value of welding current drops below preset level. It is possible to compare with preset level not entire welding current, but its component consumed from DC current source and, when value of this component exceeds preset current level, supply source is switched on periodically at fixed frequency. After each switching on of source, energy accumulated by welding current inductance elements, mainly by welding circuit connecting wires, is regenerated into welding circuit. Device for implementing the proposed method has welding circuit, DC current converter, choke, diode, comparator and transistor control unit. Device has also clock generator and at least one more choke and second and third diodes. EFFECT: enlarged operating capabilities. 8 cl, 8 dwg