Inventors:
Dale Lloyd Miller - Harrisburg PA
Assignee:
International Telephone and Telegraph Corporation - Nutley NJ
International Classification:
H02H 700
Abstract:
A bistable magnetic switch circuit includes one terminal coupled to a source of direct current voltage, a contact coupled to the other terminal of the bistable switch circuit and an armature controlled by the bistable switch circuit to make and break contact with the contact, the bistable switch circuit being energized at a given trip-rated current. A transistor has its collector coupled to the other terminal of the bistable switch circuit, its emitter coupled to a utilizing load and its base coupled to the armature remote from the contact, the transistor being rendered non-conductive when the bistable switch circuit is energized to provide the desired overcurrent protection. A reset switch is coupled between the other terminal of the bistable switch circuit and ground potential to reset the bistable switch to prepare the bistable switch circuit to protect against a continuing or a new overcurrent condition.