Design of Resistance Welder Transformers

Due to increased production demands, the speed at which resitance welders operate has been stepped up as much as four to five times during the last few years. This has been made possible in a large degree, by the development of new switching mechanisms that will allow a current dwell of a fraction of a cycle on a 60-cycle circuit. This increased speed of welding has made it necessary to study very carefully the design of the transformer and the shape and spacing of the secondary circuits, especially the cooling and protection of these parts. It has been necessary also to pay more attention to multi-transformer welders, where several transformers are used either for the purpose of distributing the secondary current to better advantage, or for the purpose of balancing the welder load on multi-phase circuits.