| 摘要 |
PURPOSE:To make it possible to reduce the circuit scale, to efficiently switch a direction of revolution of a vibrating motor, and to drive the vibrating motor at an optimum drive frequency. CONSTITUTION:A drive circuit 110 is made up of an oscillator 112, an amplifier 114, a sweep circuit 116, a resonance frequency detection section 118, a control section 120, and a changeover switch 124. A sweep is produced at an output frequency of the oscillator 112 by means of the sweep circuit 116. The resonance frequency detection section 118 detects a resonance point in this frequency range. At this time, the amplifier 114 amplifies an output of the oscillator 112 at a low amplification factor, and the amplified output is applied to a vibrating motor 100. When the vibrating motor 100 is practically driven, an output frequency of the oscillator 112 is set to an optimum drive frequency. Then, the output of the oscillator 112 is amplified at a high amplification factor, and the amplified output is applied to the vibrating motor 100. At this time, a range in which a drive voltage is applied can be switched by operating the changeover switch 124, whereby a direction of revolution of the vibrating motor is switched. |
