HIGH RESOLUTION NON-CONTACTING MULTI-TURN POSITION SENSOR

摘要

Disclosed are systems and methods for effectively sensing rotational position of an object. In certain embodiments, a rotational position sensor can include a shaft configured to couple with the rotating object. The shaft can be configured to couple with a magnet carrier such that rotation of the shaft yields translational motion of the carrier. A magnet mounted to the carrier also moves longitudinally with respect to the axis of the shaft, and relative to a magnetic field sensor configured to detect the magnet's longitudinal position. The detected longitudinal position can be in a range corresponding to a rotational range of the shaft, where the rotational range can be greater than one turn. In certain embodiments, the rotational position sensor can include a programmable capability to facilitate ease and flexibility in calibration and use in a wide range of applications.

主权项

1. A device, comprising:
a housing; a rotatable shaft having a longitudinal axis, wherein at least a portion of the shaft is within the housing; a movable carrier disposed substantially within the housing and coupled to the shaft such that rotation of the shaft results in linear motion of the carrier along the longitudinal axis; a magnet having a magnetization axis and disposed on the carrier so as to move with the carrier such that a range of rotation of the shaft results in a range of linear motion of the magnet along the longitudinal axis, the magnet oriented such that the magnetization axis is substantially perpendicular to the longitudinal axis; and a magnetic sensor circuit having a sensor element disposed relative to the magnet and substantially within the housing, the sensor element configured to sense a first flux density along the magnetization axis and a second flux density along a direction perpendicular to the magnetization axis resulting from the magnet and generate a signal based on the sensed first flux density and the second flux density, the range of linear motion of the magnet including both longitudinal sides of the sensor element such that the sensed first flux density has a maximum magnitude when the magnet is approximately aligned with the sensor element.