Schaltungsanordnung zur Stromerfassung eines Stromleiters zur Ansteuerung elektronisch steuerbarer Auslöseeinrichtungen

摘要

The invention relates to a circuit arrangement for detection of current in an electric conductor to control electronically controllable tripping devices comprising a system voltage supply device whereby operating voltage produced by a power supply device is compared with a reference voltage and the tripping device is activated by a limit voltage occurring during overload. Alternating voltage transmitted by secondary phase windings (PH1, 2, 3, n) is rectified and transmitted as service voltage (UB) to a microprocessor device (MPE) by phases that are not in measuring mode. Processor controlled measurement of phases occurs free of load and enables precise measurement results. Such circuits are used to control overload tripping devices.