POWER INVERTER FOR ELECTRIC ARC WELDING Russian patent published in 1999 - IPC

FIELD: process equipment for arc welding; small-size power supplies. SUBSTANCE: power inverter has two parallel circuits 1,2. Each circuit incorporates two series-connected thyristors 3,4 and 5,6, respectively. Supply voltage is applied across two diagonally opposite terminals at points of connection of anodes and cathodes of parallel circuits 1 and 2. Switching capacitor 10 is inserted between points of connection of anodes and cathodes of thyristors 3, 4 and 5, 6. Primary winding of output step-down transformer 9 is connected with center tap. Each half-winding 7 and 12 is connected to anode circuit of thyristors 3 and 5. Power inverter provides for pulse-width modulation when transformer carries load within each half-cycle. EFFECT: improved reliability of welding current regulation. 4 dwg