Arc welding is the use of high temperature and short-circuit the positive and negative poles at the moment generated to melt the solder and welding materials to be welded on, so that was the purpose of combining physical contact. Its structure is very simple, it is a power transformer. Welding generally based on the output power can be divided into two types, one is the AC power supply, one is current. They use the principle of inductance inductance turned on and off when the voltage change will have a huge, positive and negative poles of a high-pressure arc short circuit in an instant to melt the solder on welding, to make them achieve the purpose of atom .