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AssigneeJiangsu Multidimension Technology Co., Ltd.
InventorsJianmin Bai, James Geza Deak, Hua lv, Weifeng Shen
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The present invention discloses a magnetoresistive gear tooth sensor, which includes a magnetoresistive sensor chip and a permanent magnet. The magnetic sensor chip is comprised of at least one magnetoresistive sensor bridge, and each arm of the sensor bridge has at least one MTJ element group. The magnetoresistive gear tooth sensor has good temperature stability, high sensitivity, low power consumption, good linearity, wide linear range, and a simple structure. Additionally, the magnetoresistive gear tooth sensor has a concave soft ferromagnetic flux concentrator, which can be used to reduce the component of the magnetic field generated by the permanent magnet along the sensing direction of the MTJ sensor elements, enabling a wide linear range. Because it is arranged as a gradiometer, the magnetoresistive gear tooth sensor bridge is not affected by stray magnetic field; it is only affected by the gradient magnetic field generated by gear teeth in response to the permanent magnet bias. The magnetoresistive gear tooth sensor of the present invention is able to detect the position of a specific tooth or a missing tooth of a gear. This magnetoresistive gear tooth sensor is also capable of determining the speed and direction of motion of a gear.
A magnetoresistive gear tooth sensor, comprising a first permanent magnet and a sensor chip that includes at least one sensor bridge, wherein each arm of the sensor bridge is comprised of at least one MTJ element group, wherein each MTJ element group is comprised of at least one magnetoresistive MTJ element.
The magnetoresistive gear tooth sensor of claim 154, comprising two full sensor bridges, wherein each arm of the two full sensor bridges includes a magnetoresistive MTJ element group, and the microcontroller is used to determine the movement direction of a gear using the voltage output of the magnetoresistive gear tooth sensor.
Dependencies are inferred from the claim text.