摘要 |
A magnet which is attached to a rotary body and which is rotatable together with the rotary body; an annular yoke which extends annularly to surround an outer peripheral surface around a rotary shaft of the magnet and in which a notch portion is formed in a part in the extending direction; and a hall element which is disposed in the notch portion and which detects the strength of a magnetic field in the radial direction of the magnet and detects the strength of a magnetic field in the rotation angle direction perpendicular to the magnetic field in the radial direction of the magnet are provided. The angle of rotation of the magnet is calculated on the basis of signals corresponding to the magnetic field strengths in the radial direction and rotation angle direction detected by the hall element.
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