| 摘要 |
PURPOSE:To reduce an error signal even when the magnetizing accuracy is poor by specifying the ratio of the number of poles of multipolar magnetization for detecting the rotating speed to that of multipolar magnetization for driving. CONSTITUTION:When the number of poles of multipolar magnetization for driving a motor is represented by 2j poles (j=1, 2, 3...) and the number of poles of multipolar magnetization 3' for detecting the rotating speed is represented by 2k (k=1, 2, 3...), the magnetizations 3' for driving a motor and detecting the rotating speed are executed for a cylindrical magnet 2' with k/2j as an integer number. When thus constructed, the output induced by the variation in the magnetic flux due to the multipolar magnetization for driving the motor is cancelled, and the influence of the irregular magnetization for the FG output of a generating coil 5' can be minimized. |
