SMART IGBT CONTROL -- SALI welder is controlled by IGBT(Insulated Gate Bipolar Transistor), master current more exactly, low splash and smooth in weld joint, help us make a perfect welding. · FULL PROTECTION -- Automatic power-off protection for overheating. Thickening version aluminium alloy radiator designed in serrated, radiating in sectional type. 4100 turn/min mute fan for fast heat dissipation. · SAFE AND STABLE -- Digital chip control, arcing immediately. Built-in ultra low voltage intelligent regulator, started in unstable voltage area easily.