1. High quality welding with high resolution 2. Realizing clean welding environment due to splash free welding by accuracy heat input control 3. Excellent welding strength by deep penetration in hardware welding 4. Free from phase unbalance and low power factor in single phase AC welding 5. High durability of welding transformer no using secondary rectifier diodes as compared with 3 phase DC inverter welding 6. Precise Machined C-frame makes high quality projection welding by securing high perpendicularity and parallelism between electrodes.