Electrical apparatus comprising a controlling device, a support and surveillance device for such an apparatus, and their electric installation

摘要

An auxiliary contact (12), moving with the main switch contact (2), short circuits an inductor (11). This is sensed by a processing circuit (17) controlling an oscillator which drives a second inductor (15), coupled to the first coil. Alternatively, the inductors may be replaced by tuned circuits. The indicating deices are connected to a central monitoring station (20).