1) DC TIG INVERTER WELDING MACHINE 2) POWER SAVING welding MACHINE 3) HIGH EFFICIENCY ... low carbon steel, carbon steel, alloy steel, etc.; Advanced inverter technology: Inverter frequency up to 100KHz, conversion rate of 85%, no-load ... non-adjustable, easy to use, easy to carry, reliable and economical and durable; Precise control system: PWM Pulse Width Modulator, closed ...