... 4T control,ease of long-weld operations dc/ac inverter square wave spot welding machine TIG200PACDC:welding style: DC TIG, ... carbon steel, copper, titanium and other materials;advanced inverter technology:dual inverter control technology, the conversion efficiency of 85%, no- ... is stable;excellent welding performance: 1. quality square wave power supply,current zero-crossing time is short,stable ...