A TARGET WHEEL SENSOR ASSEMBLY FOR PRODUCING AN ASYMMETRIC SIGNAL AND FOR DETERMINING THE DIRECTION OF MOTION OF THE TARGET WHEEL BASED ON THE SIGNAL SHAPE

摘要

A target wheel sensor assembly includes a sensor that is placed near a target wheel. The sensor includes a magnet to create a flux and a sensing element to sense changes in the flux as the target wheel rotates. The target wheel is alternatingly formed with multiple teeth and multiple slots. Each tooth includes a flat portion that is parallel to the bottom of the sensor and a chamfered portion contiguous to the flat portion. The chamfered portion forms an angle, alpha, with the bottom of the sensor. As the target wheel rotates, the shape of the teeth in conjunction with the slots cause the sensor to output an asymmetric signal. The shape of the signal is used to determine the direction of motion of the target wheel.