The principal functions of resistance welding controls are
(1) to provide signals to control machine actions, (2) to start and stop the current to the welding transformer, and (3) to control the magnitude of the current. There are three general groups of controls: timing and sequencing controls, welding contactors,
and auxiliary controls.
Electronic control of resistance welding machines has enabled manufacturers to use this process in precision production, and made possible its extension to welding a wide variety of metals and alloys, such as stainless steel, brass, bronze and aluminum.
For information on electronic controls for resistance welding, and such auxiliary electronic equipment as heat controls, upslope and downslope current controls, quench and temper controls, forge delay controls, electronic current and voltage regulators, electrical power load distribution, and monitoring and adaptive controls, see Resistance Welding Controls, American Welding Society, Welding Handbook, Vol. 2, 8th Edition. Miami, Florida: American Welding Society, 1991.