Does anyone know what the 'compensator' circuits of portable spot welders is and how they achieve their objective? I know (from adverts) that they are supposed to compensate for slight contamination of the sheets with oil and paint and are recommended for use with galvanised sheet - but haven't a clue how they do it.
I've just acquired a "SIP M2 Spotmatic" (labelled M22 !) with compensator, and sure enough it seems to have no problems with light oil and galvanising but WHAT is the compensator doing?????? The works look the same as my broken spot welder - just a wacking great single turn on a mains transformer with a timer added.
Puzzling !
AWEM