Abstract
This paper deals with a tachometer by using the basic property of the moiré profile. This tachometer has the moiré profile detecting device with two radial gratings and the photo-transistors and the simple operational circuits mathematically analyzed. In terms of the experimental results, it is revealed that the linearity of the output for the speed of rotation is less than one percent variation, and that the ripple content of the output is one-fifth of the conventional tacho-generator. The experimental results are in good agreement with the theory based on the simulational model. In addition to the reduction methods of the ripple content at the low speed of rotation is suggested.
