A new timer for resistance welding

A new type of timer and controller for use in the field of resistance welding of thin alloy sheets of brass, aluminum, stainless steel, and kindred metals where a very high current is applied for a very short interval of time is described in this paper. In this new timer, the “ignitron” type of tube is applied for obtaining precise control of the welding current. Controls for intermittent duty, high speed automatic duty, and heavy duty seam welding are described.