POLARISED ELECTROMAGNET WITH THREE POSITIONS AND CONTROL CIRCUIT

摘要

A three-state polarized electromagnet comprises a stationary system (1) surrounded by a coil (5) and a moving system (7). Each system consists of a permanent magnet (2; 14) fitted with pole pieces (3, 4; 12, 13). The ends of the pole pieces are bent-back towards each other in order to define four air-gaps (E1 to E4) for permitting displacement of the moving system (7) between two end positions. One end portion of a pole piece forms part of only one air-gap and the air-gap faces are joined to pole faces of permanent magnets having the same polarity in order to reduce to zero the fluxes within the air-gaps which are closed when no excitation is applied and in order to permit a return to a stable central position.