Optimisation of electric contact erosion by arc energy equalisation

Describes some work carried out on 240 V-rated snap-action switches. These switches are used, typically, in thermostatic control systems where there is a slow thermally-activated prime-mover whose movement must be converted into an electric make and break action. Sometimes switch contacts become severely eroded after many years of use, for example, in a refrigerator, and weld together causing system failure. The first stage of the study involved high-speed photography of the snap-action mechanism to determine the break characteristic