ROTATION DETECTING DEVICE

摘要

PROBLEM TO BE SOLVED: To provide a rotation detecting device by which a failure can be detected quickly. SOLUTION: This rotation detecting device is constituted by providing a sensor disk 3 which is turned with the rotation of an object to be detected. In addition, the rotation detecting device is constituted by providing at least three sensors 4 which output pulse signals at phases which are different according to the rotation of the sensor disk 3. In this case, the sensors 4 are installed in such a way that outputs of all the pulse signals do not become a high level or a low level irrespective of the rotating position of the sensor disk 3.