METHOD AND APPARATUS FOR DETECTING RELATIVE POSITION BETWEENTWO RELATIVELY ROTATABLE MEMBERS USING CONCENTRIC RING

摘要

PROBLEM TO BE SOLVED: To obtain an apparatus for sensing the relative rotational positions of the stator and rotor in a variable reactance motor. SOLUTION: This apparatus includes a transmission ring 40, having a transmission coil provided for the rotor 32, and a receiving ring 42 having a receiving coil 56 provided for the stator. The receiving coil 56 includes three insulated conductor patterns of identical shape, shifted by 120 deg. electrical angle from each other. A drive signal is applied to the transmission coil. The inventive apparatus further includes a controller for monitoring the output from pattern of the receiving coil and determining the relative rotational position of the rotor 32 and the stator. Each receiving coil is arranged in a circumferentially variable square-wave pattern.