Stable performance; due to the welding machine's working frequency of 20KHZ or more, with a faster response speed, can be divided into multiple stages of droplet transfer control. For CO2 gas shielded welding, spattering can be greatly reduced. The stability of the jet transition can be effectively controlled for pulsed MIG/MAG welding. It is also possible to combine the droplet transfer with the movement of the wire feeding mechanism to further control melting. Drop transition process, get a good weld formation, stable welding performance. These are the traditional rectifier welding machine can not do.