AC-excited switching electromagnet e.g. for motor protection - has excitation winding surrounding only field space bounded by pole width and packet thickness of magnet

摘要

The electromagnet consists of a U-shaped armature (1), a flat core (2) and a composite excitation winding (3) in two parts e constructed as a cassette reel. This is shaped so that the winding encloses only the working field space of the magnet in the initial position with the armature (1) unexcited. The direction of insertion of the cassette reel through its guides and bearing elements follows that of the current paths so that reels can be exchanged even when a number of equipments are connected in series with one another. ADVANTAGE - Sufficient magnetic force is guaranteed and coils can be replaced without difficulty in assembled state of equipment, with no internal electrical connections needing to be broken or parts of magnetic circuit disturbed.