| 摘要 |
PURPOSE:To obtain a good driving performance by providing a driving voltage forming circuit where the driving voltage is set lower than the power supply voltage or controlled depending on the value of power supply voltage thereby supplying a stabilized driving voltage. CONSTITUTION:An ultrasonic motor is set to exhibit a desired driving performance when the output driving voltage from switching circuits 4, 5 equals to VM and a driving voltage forming circuit 1 generates a driving voltage VM equal to the power supply voltage Vo under control of a microcomputor 10. In this regard, the switching circuits 4, 5 convert the driving voltage VM into an alternating voltage which is boosted through boost coils 6, 7 and fed to moving electrodes A, B thus rotating the ultrasonic motor with a desired driving performance. Since the driving voltage VM is applied to the motor itself even upon fluctuation of the power supply voltage Vo, the motor can be driven with a desired driving performance. |
