A
welding power supply is a device that provides an
electric current to perform
welding. Welding usually requires high current (over 80 amperes) and it can need above 12,000 amperes in
spot welding. Low current can also be used; welding two razor blades together at 5 amps with
gas tungsten arc welding is a good example. A welding power supply can be as simple as a
car battery and as sophisticated as a high-frequency inverter using
IGBT technology, with computer control to assist in the welding process.