Method and apparatus for determining the rotational position of a magnetic rotor relative to current carrying coils utilizing magnetic coupling between coils

摘要

An apparatus includes a rotatably mounted magnetic rotor, a first coil mounted in proximity of the magnetic rotor, the first coil mounted such that, if the coil is flowing with electric current, the magnetic rotor is within immediate proximity of at least part of a magnetic field created by the coil. The apparatus includes a second coil mounted in proximity of the magnetic rotor, the second coil mounted such that, if the coil is flowing with electric current, the magnetic rotor is within immediate proximity of at least part of a magnetic field created by the coil. A current source is coupled to the first coil, for generating an AC signal and applying the AC signal across the first coil whereby an AC output signal develops across the second coil, the AC output signal having a magnitude that varies in relation to the rotational position of the rotor. A measuring circuit detects the AC output signal and develops therefrom a measure of the position of the rotor.