| 摘要 |
PURPOSE:To eliminate a magnetic detector exclusive for detecting the rotating phase by providing a magnetic discontinuous unit on a field magnet, and generating the variation in the detection signal in the element to detect the rotating phase of a rotor. CONSTITUTION:A frequency generator 2 of a rotor is connected with the input terminal P3 of an IC1 for controlling, and a control signal for maintaining a set speed is output from the terminal P3 to an IC3 for driving. Magnetic detector 4 is connected with input terminals P1-P6. An annular field magnet is provided on the rotor, and magnetized in different polarities alternately in the circumferential direction. In this case, a rare earth magnet to become a magnetic discontinuous unit is mounted at the prescribed position. A phase detector 8 is formed of a comparator 9 and a monostable multivibrator IC10. Thus, the variation in the magnetic flux by the discontinuous unit is detected by a detector 8 in the rotary phase of the rotor by detecting by the detector 4 to rotate the rotor sequentially through the armature coil 7. |
