Circuit arrangement for operating heavy-duty equipment using electrical relaying device

摘要

A circuit arrangement operates a heavy-duty electrical equipment including an electrical relaying device having a relay coil and a set of first and second relay contacts. The first relay contacts are connected in a circuit that supplies a large amount of current to the electrical equipment. The relay coil is connected to be energized with a small amount of current in response to the closure of a normally open switch and held energized in response to the closure of the second relay contacts. The normally open switch and the second relay contacts form a closed low impedance circuit which supplies an arc current pulse to the second relay contacts during the time when the normally open switch is held closed, whereby fragmentary objects or dust collected between the second contacts is removed as the first and second contacts chatter during a closing.