How does a remanence relay work?

A remanence relay works through magnetic remanence: when the relay is switched, residual magnetism remains in the magnetic core, which keeps the armature in its position even if the supply voltage is switched off. The switching state is therefore stored stably until a new control signal generates an opposite magnetic field that compensates for the existing residual magnetism. Only then is the relay deliberately switched into the new state. In this way, it only requires energy during the switching process and combines high efficiency with operational reliability.