| 摘要 |
PURPOSE:To effectively start a rotor magnet by applying a starting torque to a rotor magnet by a free-running multivibrator at the rotor magnet driving time, thereby eliminating the necessity of a special pole position detector. CONSTITUTION:When a power source is supplied to a gyro device, a free-running multivibrator 13 oscillates a rectangular wave, and supplies a drive current I2 to drive coils 7, 8 by a drive circuit 2. A rotary torque is generated at a rotor magnet 4 by the mutual magnetic action of the current I2 and the magnet 4, and the magnet 4 starts rotating. Then, since a magnetic flux received from the magnet 4 is varied in reference filters 9, 10, an inducted voltage is generated by electromagnetic induction, and the voltage is converted by a zero-cross comparator 11 into a rectangular wave. A drive current I2 is supplied to the drive coils 5, 6 by a drive circuit 1 to accelerate the magnet 4. |
