Overcurrent trigger for fast DC switch

摘要

The over-current trigger includes a magnetic yoke (2) which encloses a conductor (1), and in whose extent an armature (3) is movably arranged. The armature is held through a force (F) in a rest position, and forms together with the yoke a first air-gap (LH) and second air-gap (LA). A magnetic flow ( phi H) supporting the force, is formed in the first air-gap, and a magnetic flow ( phi A) counteracting the force is formed in the second air-gap. The iron cross-sections of the yoke and the armature are dimensioned in such way, that the magnetic flow in the second air-gap prevails above a predetermined current flowing in the conductor, so that the armature is moved from its rest position. The magnetic yoke includes a first thigh pair (9) and a second thigh pair (8), which proceed parallel to each other, and parallel to a yoke floor. The first thigh pair forms the first air-gap with the armature, and the second thigh pair forms the second air-gap with the armature. A first aperture is formed between the first and the second thigh pair, and a second aperture is formed between the second thigh pair and the yoke floor. The conductor is straight and proceeds vertically to the flow direction within the second aperture. The armature moves within the first aperture between the first and the second thigh pair.