| 摘要 |
PROBLEM TO BE SOLVED: To obtain a drive controller for ultrasonic motor using a simple circuit configuration, which can stably control the rotational drive of an ultrasonic motor to the maximum capacity in real time. SOLUTION: A device for controlling the drive of ultrasonic motor is provided with frequency control means 2 and 4 which can variably control the frequency of a drive frequency signal SD for driving an ultrasonic motor 1, an amplitude voltage detecting means (sensor electrode) S, which detects the oscillation frequency of the motor 1 as an amplitude voltage VD, and a comparing means 7 which compares the amplitude voltage VD' obtained from the oscillation amplitude with a preset reference voltage VREF and outputs the compared result as a comparison signal SC. The controller is constituted so as to fix the frequency of the drive frequency signal SD by means of the frequency control means 2 and 4, when the comparison signal outputted from the comparing means 7 changes. |
