Reduced dissipation active device for use with device for reading state of dry contact under high voltage, has comparing unit comparing phase difference to ranges of predetermined phase-shifting defining two states of activating switch

摘要

The device has an electric circuit (33) connected to a series of terminals of a winding (36) of a transformer (24). A measuring unit (31, 32) measures the phase difference between alternative voltage and current of another electric circuit (37). A comparing unit compares the phase difference to two ranges of predetermined phase-shifting respectively defining two states of an activating switch (21). A single condenser (23) is connected on the winding.