Auto-drive or synchronous variable reluctance polyphase stepper motor rotor shaft angular position detector - connects series pole windings to constant amplitude HF AC generator to obtain at terminals of each phase voltage with envelope modulated uniquely by position of rotor teeth relative to stator

摘要

The toothed stator (11) and rotor (31) have similar magnetic circuits mounted on the same shaft (1) which precisely aligns them. Upon each pole (12) of the stator (11) is wound a coil (16). The windings on diametrically opposite poles are connected in series to form one phase of the detector (10). The phases are connected to a constant amplitude high frequency AC generator so that they are synchronised with currents of the same amplitude. This gives by rotation at the terminals of each phase an amplitude modulated voltage whose modulation envelope uniquely depends on the position of the rotor teeth with respect to the stator teeth of each phase. USE/ADVANTAGE - Has simplified electronic circuits which make them insensitive to temperature variations. Serves also as speed detector.