Spot welding has been used in many industry fields such as aviation, spaceflight,atomic energy, electron technology and automobile etc. On abroad, the mid-invertspot welding servo-robot has been used by the motor manufactory (U.S.A. and J.P)in Automatic production line. There are around 4000~6000 spots in a body of car,The more use of welding servo-robot the higher the automatization level is.Generally we most use welding power supply which is between50KVA~75KVA .This need the power supply smart and ...