| 摘要 |
A magnetic rotary position sensor comprises a base 20 eg a silicon substrate or ceramic upon which a plurality of radially extending magnetic sensor elements 22 are mounted, each of the elements placed in an individual gap 31 between uniformly spaced generally triangular shaped magnetic field concentrators 30. The base is placed in a uniform magnetic field eg created by spaced magnets of opposite polarity 32,34 or a ring magnet (332, Fig. 7). Each of the sensor elements may comprise giant magnetoresistive (gmr) elements or a Hall detector. A separate hall detector (56, Fig.4) may be provided on the base to allow determination of the direction of the applied magnetic field should the rotary sensor with rotate a full 360{. The concentrators may comprise any soft ferromagnetic material such as iron, nickel-iron alloy, nickel and some ferrites. Alternative arrangements of the sensor elements are disclosed (Figs.5,6 and 9). The rotary sensor device may be as small as 4mm x 4mm and requires little or no temperature or magnetic field calibration. |
