... (ZX7 400) 1. Discrete IGBT 2.Precise Control 3.Excellent Welding Performance MMA Inverter Welding Machine (ZX7 400) Functions ... ,Medium Carbon Steel,Alloy Steel,etc. 4) Advanced Inverter Technology:Portable,light,portable and cost effective.Voltage compensation ... ) Precise Control System:Adopted full-bridge inverter technology with advanced single-tube IGBT and frequency about 25KHZ,Current-mode Pulse ...