ROTATION SENSOR

摘要

A rotation sensor has a magnetoelectric conversion unit that converts change of magnetic flux whose direction changes periodically with rotation of a rotator into an electric signal and a processing unit that processes the electric signal. The magnetoelectric conversion unit outputs a first detection signal and a second detection signal. The processing unit has a first comparison unit that compares a detection threshold and the first detection signal and a second comparison unit that compares a reference threshold and the second detection signal. The first comparison unit changes a voltage level of the detection threshold when the first detection signal exceeds or falls below the detection threshold and then restores the voltage level of the detection threshold based on the second detection signal and the reference threshold, and the first comparison unit converts the first detection signal into a pulse signal based on the detection threshold of the same voltage level.

主权项

1. A rotation sensor that detects a rotation state of a rotator based on change of magnetic flux whose direction changes periodically with rotation of the rotator, the rotation sensor comprising:
a magnetoelectric conversion unit that converts change of magnetic flux whose direction changes periodically into an electric signal; and a processing unit that processes the electric signal of the magnetoelectric conversion unit, wherein the magnetoelectric conversion unit outputs, as the electric signal, a first detection signal and a second detection signal having the same period and different phases, the processing unit has a first comparison unit that generates a detection threshold and compares the detection threshold and the first detection signal and a second comparison unit that generates a reference threshold and compares the reference threshold and the second detection signal, the second detection signal acts to fall below or exceed the reference threshold only once during a period from a time the first detection signal exceeds the detection threshold to a time the first detection signal falls below the detection threshold and during a period from a time the first detection signal falls below the detection threshold to a time the first detection signal exceeds the detection threshold, the first comparison unit changes a voltage level of the detection threshold when the first detection signal exceeds or falls below the detection threshold, restores the voltage level of the detection threshold when the second detection signal falls below or exceeds the reference threshold only once, and changes the voltage level of the detection threshold when the first detection signal falls below or exceeds the detection threshold of the same voltage level, and the first comparison unit converts the first detection signal into a pulse signal that has a pulse rising edge when the first detection signal exceeds the detection threshold and has a pulse falling edge when the first detection signal falls below the detection threshold of the same voltage level.