As used in a-c welding machines, reactor controls provide for remote adjustment of welding currents. The reactor control consists of a motor-driven gear device that may be applied to crank-adjusting units, or a rheostat at the work station for reactors that are adjusted electrically. Foot-operated remote control units are available which permit a gradual buildup or reduction of the welding current. This type of control device is useful in preventing weld craters.
