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.