Control for electric resistance welding - compares actual welding parameters with previously determined ideal values

摘要

The welding potential employed when spot welding two sheets using electrodes, a welding transformer and a phase control unit is monitored and integrated by two units over the welding time. This actual value parameter is fed to a comparator which compares it with ideal values determined through prior experimentation using test welds. The ideal value and its limits are stored in a unit which can be supplied with external programmes or manual ideal value selections. Should deviations occur from the ideal value or its limits, then the comparator feeds a control impulse to the controller which in its turn regulates the phase control unit for the welding transformer. By this means, satisfactory welding results can be achieved over a long time span.