Patent ID: 7219562
Filing Date: 2007-05-22
Classification: G01D

Abstract:
1. An angular position sensor comprising two magnets attached to a rotor for generating a magnetic field and a magnetism detection device disposed in the magnetic field for detecting changes in the magnetic field on rotation of the rotor so that the angular position of the rotor is detected based on the changes in the magnetic field to provide an output signal from the magnetism detection device indicating the angular position of the rotor, wherein a flux concentrating stator provided comprising a pair of stator pieces is positioned substantially on either side of the magnetism detection device and the two magnets are positioned substantially opposite to each other so that a face of a pole of one magnet faces a face of a pole of the other magnet and the two other poles face away from each other, the pole faces defined between an upper edge and a lower edge spaced apart by two side edges and wherein the length of the upper edge or the lower edge of each pole face is substantially three times the length of an edge of the stator pieces.