Honeywell International Inc.

Honeywell G.m.b.h.

Robert E Bicking

Perry A Holman

Kent E Van Ostrand

Greg R Furlong

Edward L Stern

Ed L Stern

A sensor signal conditioning circuit and sensor system incorporating the same. In one embodiment, the signal conditioning circuit includes a DC-coupled detector that converts a sensor signal into a discrete level signal. An AC-coupled detector having a dynamic DC threshold input also converts the sensor signal into a discrete level signal and has a startup delay associated with the dynamic DC threshold input. The signal conditioning circuit further includes a device that inhibits the DC-coupled detector responsive to the dynamic DC threshold input reaching a specified threshold voltage level such that the AC-coupled detector provides the detected output during steady-state sensor operation.

Sensor signal conditioning circuit

A proximity sensor that is capable of producing a relatively larger output signal than past proximity sensors, and in some cases, an output signal that is relatively independent of the speed at which a target passes the sensor. In one illustrative embodiment, the proximity sensor includes a first magnetoresistive resistor and a second magnetoresistive resistor connected in a bridge configuration. The first magnetoresistive resistor is spaced from the second magnetoresistive resistor along the path of a moving ferrous target. A bias magnet source is positioned behind the proximity sensor, and the ferrous target passes in front of the proximity sensor. The ferrous target alters the direction of the bias magnetic field in the vicinity of the first and second magnetoresistive resistors as the ferrous target passes by the proximity sensor. Flux concentrators are positioned proximate to each of the first and second magnetoresistive resistors. The flux concentrators may help redirect or shunt the magnetic field component produced by the bias magnet source that is perpendicular to the direction of motion of the target through the first and second magnetoresistive resistors in a direction that is parallel to the direction of motion of the target.

GMR sensor with flux concentrators

A method and system for sensing linear position utilizing a magnetoresistive bridge circuit. A permanent magnet is provided having a gap formed therein. The magnetoresistive bridge circuit is generally located within the gap of the permanent magnet. The magnetoresistive bridge circuit includes a plurality of magnetoresistors. The magnet can be positioned in proximity to the ferrous target, which is associated with a slider that moves along a shaft. The magnetoresistive bridge circuit is generally biased by a magnetic field of the magnet. The magnetic field can saturate the magnetoresistive bridge circuit and a response of the magnetoresistors thereof. An output signal of the magnetoresistive bridge circuit can then be detected such that the output signal is produced by a change in an angle of the magnetic bias field. The output signal determines a target position with respect to a torque applied to the shaft.

Saturated magnetoresistive approach for linear position sensing

A method and apparatus for minimizing errors in a sensor device due to signal amplitude variation are disclosed herein. A signal output from the sensor device is amplified and, thereafter, AC-coupled to a comparator such that the amplification and AC-coupling of the signal minimize offset shift-related errors associated with the sensor device. The signal can be coupled to eliminate offset shifts due to component mismatches, calibration, aging and/or temperature associated with the sensor device. An AC-coupled sensor signal conditioning circuit is utilized to amplify the signal through an amplifier and then AC-couple the signal to a comparator.

AC-coupled sensor signal conditioning circuit

An interleaved parallel MR bridge array is optimized for sensing fine pitch ring magnets and can be utilized to reduce ring magnet target size for wheel speed sensing applications.

Magnetoresistive bridge array

A geartooth target providing a consistent magnetic signal for each feature type with unambiguously readable features has three unique 30&deg; segments, each segment ending with a falling edge transition, the segments placed to have a unique pattern of segments every 90&deg;.

Target design for geartooth sensor with minimal number of unique segments combined in nonrepeating fashion

A geartooth sensor is provided with a circuit which determined a threshold magnitude as a function of the minimum value of a first output signal from a magnetically sensitive component and an average output signal from a magnetic sensitive component. Circuitry is provided to determine the average signal. The minimum signal is then subtracted from the average signal and the resulting signal is doubled before being scaled by a predetermined fraction and then compared to the original output signal from the magnetically sensitive component. This circuit therefore determines a threshold signal as a function of both the minimum signal value and the average signal value and, in addition, enables the resulting signal to be scaled to a predetermined percentage of this difference for the purpose of selecting a threshold value that is most particularly suitable for a given application.

Geartooth sensor with means for selecting a threshold magnitude as a

A position sensor is provided with two target tracks which each comprise a plurality of magnetic and nonmagnetic segments. Each target track is associated with a magnetically sensitive device such as a Hall effect element. By appropriately positioning the locations of the pluralities of magnetic and nonmagnetic segments, output signals from the magnetically sensitive devices can be caused to generate preselected signal patterns. These signal patterns can be combined to synthesize a third output signal having a signal pattern of a desired characteristic which would otherwise be unobtainable through the use of a single target path configured with magnetic and nonmagnetic segments to directly generate the desired signal pattern.

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Freeport, IL, United States of America

Robert E Bicking