Resistance welding is a fusion welding process that requires the application of both heat and pressure to achieve a sound joint. The simplest form of the process is spot welding where the pressure is provided by clamping two or more overlapping sheets between two electrodes .
Resistance Welding is a thermo-electric process where heat is generated at the interface of the parts to be joined by passing an electrical current through them or a precisely controlled time and under a controlled pressure (also called force.
Therefore, to get the 10,000 amps needed for resistance welding, some device must be used to step the current up from the relatively low level available from the power line. The device generally used is a transformer.
