OVER-CURRENT PROTECTION RELAY

摘要

PROBLEM TO BE SOLVED: To provide a relay having the over-current protecting function without any additional structural element required for a load circuit. SOLUTION: An energizing coil (2) of an electromagnetic system (1) is used as a load current sensor to protect a relay from overload or short-circuit. In the case where a section (5) in a load current circuit is, for example, the auxiliary coil is allocated so that a voltage is induced in an energizing circuit and induced voltage is superimposed on the energizing voltage when a current flows into the load circuit. An electronic unit evaluates this voltage signal and when the voltage signal exceeds the load current threshold value, the relay is turned off.