| 摘要 |
A magnetic sensor for sensing the proximity of a magnetically permeable member, the sensor and member being relatively movable with respect to each other and having an axis of movement disposed within a fixed plane. The magnetic sensor includes two coplanar magnetoresistive elements, each element having a main current conducting path and possessing anisotropic resistance as a function of the direction of a resultant magnetic field applied thereto. The two magnetoresistive elements are connected in series, and a d.c. current is supplied to the series-connected elements. First and second saturating bias magnetic fields are supplied, as by a bias magnet, to respective ones of the magnetoresistive elements at the same angle theta o to each of the respective main current conducting paths in the absence of the magnetically permeable member. The angle at which each bias field is supplied is changed by substantially equal and opposite small deviation angles +/- DELTA theta in response to the relative movement of the permeable member proximate the magnetic sensor. An output circuit is coupled to the junction defined by the series-connected magnetoresistive elements to produce an output signal which varies as a function of the deviation angles by which the angles of the bias fields change.
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