Plug-unit for switch=off monitoring esp. in HV power switch - has at least one evaluator output coupled to control relay for switch off circuit

摘要

A shunt impedance (10) with anti-parallel diodes (11, 12) is arranged on a fixed part of the plug-in unit (7), and the plug in card includes an evaluator logic device (30). To the inputs of this device on the one hand are coupled the switch-off circuit for the monitored device (4), and decade switches (22), and one the other hand via an isoaltor transformer (13) with secondary tapped resistor (14) the rectifier (16) with downstream connected comparator (21) and electronic components of the shunt impedance. At least one evaluator output is coupled to a control relay (23) for the switch off circuit. ADVANTAGE - Conventional plug-in device without strengthened contacts.