Intelligent field shaping for magnetic speed sensors

摘要

The present disclosure provides for techniques to improve the sensitivity of magnetic sensor systems. One embodiment of a magnetic sensor system includes a magnetic biasing body comprised of a hard magnetic material and including a recess therein. The recess corresponds to a magnetic flux guidance surface of the magnetic biasing body. The magnetic sensor system also includes a magnetic sensing element arranged in or proximate to the recess. A magnetic flux concentrator, which is made of a soft magnetic material, is disposed in the recess between the magnetic flux guidance surface and the magnetic sensing element. Other techniques are also described.

主权项

1. A magnetic sensor system, comprising
a rotary element including a plurality of magnets arranged about an outer circumference thereof; a magnetic biasing body spaced apart from the rotary element and comprised of a hard magnetic material and including a recess therein, wherein the recess includes sidewalls and a lower surface and corresponds to a magnetic flux guidance surface of the magnetic biasing body; a magnetic sensing element arranged to sense changes in magnetic field orientation at a location in or proximate to the recess; and a soft magnetic material disposed in the recess over the lower surface and between the sidewalls, the soft magnetic material arranged between the magnetic flux guidance surface and the magnetic sensing element, the soft magnetic material being configured to reduce a magnetic field due to the magnetic biasing body at the location where the changes in magnetic field orientation are sensed by the magnetic sensing element.