Abstract: A proximity sensor has two magnetoresistive elements in a common plane and displaced from a lateral surface of a permanent magnet. The common sensing plane of the magnetoresistive elements extends in a direction generally parallel to a magnetic axis of a permanent magnet that extends between the north and south poles of the magnet. A detection zone is defined relative to a preselected magnetic pole face and the magnetoresistive elements provide first and second signals that can be compared to define a third signal which is representative of the presence or absence of the magnetically permeable object within the detection zone. The magnetoresistive elements can each have a plurality of magnetoresistors which are arranged in a Wheatstone bridge configuration for the purpose of providing the first and second signals described above.

Abstract: A magnetic sensor is provided with two target tracks arranged in generally parallel association with each other. Each of the target tracks comprises magnetic and nonmagnetic segments which are arranged in alternating patterns. Each magnetic segment of the first target track is disposed alongside a nonmagnetic segment of the second target track and each magnetic segment of the second target track is disposed alongside a nonmagnetic segment of the first target track. First and second magnetically sensitive components are disposed proximate the first and second target tracks, respectively, and a source of a magnetic field is disposed proximate the first and second magnetically sensitive components. Distortions of the magnetic field imposed perpendicularly on the first and second magnetically sensitive components are used to provide first and second output signals therefrom.

Abstract: A gear tooth sensor is provided which incorporates a magnet and two magnetically sensitive devices, such as Hall effect elements. The two magnetically sensitive devices are disposed in a common plane with each other with one of the devices being located at a position closer to the magnet than the other device. The common plane in which both magnetically sensitive devices are disposed is spaced apart from a central axis of the magnet by a predetermined distance. A divider is provided for determining a ratio of the magnetic field strengths that are imposed perpendicularly on the first and second magnetically sensitive devices. The ratio is used to distinguish between teeth and slots proximate the sensor wherein the common plane of the magnetically sensitive devices is generally perpendicular to the path along which the teeth and slots pass.