secondary is direct current return;silicon diode to rectify;DC heating;No alternation electromagnetic force between throat; ModelRated PowerInput VoltageDuty CycleWelding CapacityStrokeGapKVA %Low carbon steelAluminum alloymmmmCDZ2525380V/50Hz/1352.5+2.50.8+0.85070CDZ4040380V/50Hz/1503.0+3.01.0+1.05070CDZ6363380V/50Hz/1504.0+4.01.0+1.080260CDZ100100380V/50Hz/1505.0+5.01.5+1.580290CDZ125125380V/ ...