Current discharge monitor for HV insulation tester - uses specialised transformer coupling to display monitor

摘要

The coupling circuit is used in an HV test apparatus. It tests the insulation on a piece of electrical equipment (1). A specialised multiple winding transformer is used to couple the test-piece (1) circuit via a transmission line to an output monitor. The device under test (1) is subjected to a high voltage in the appropriate way and is connected to earth through the primary winding (2) of the special design transformer. A secondary winding conducts any discharge signal via a transmission line (5) to a monitor (8) while high frequency signal overload is prevented by a protection circuit (7) connected across a tertiary winding (6).