| 摘要 |
PURPOSE:To always drive a slider at the prescribed speed by controlling the oscillating frequency of a control oscillator having a free-running frequency controller by the output of a speed sensor, and suitably determining the free- running frequency of its control oscillator. CONSTITUTION:The speed of a slider 2 is detected by a speed sensor 4, and the oscillating frequency of a control oscillator 9 is controlled. The output of a free-running frequency controller 10 is applied to the oscillator 9. The controller 10 sets the free-running frequency of the oscillator 9 to satisfy the relationship of f=f0 and 0.99-f0<f<1.01Xf0, where (f) is the free-running frequency in the oscillator 9, and f0 is the resonance frequency of a piezoelectric vibrator or the resonance frequency of a system. A drive circuit 5 receives the output of the oscillator 9 and dries a piezoelectric vibrator 3. |
