| 摘要 |
PURPOSE:To improve the efficinecy of a surface wave motor by providing AC voltage control means for controlling 2-input AC voltages of the motor, thereby always maintaining the 2-input AC voltages constant. CONSTITUTION:In order to operate a surface wave motor M, AC voltages which are displaced in phase of 90 deg. are inputted to the input terminal of a piezoelectric element. The two input AC voltages are outputted from an oscillator 9a of a power source 9, amplified by an amplifier 9b, and inputted through a coil 8 to input terminals A, B, thereby driving a rotor. The amplitudes of the two voltages are compared by a voltage comparator 10, and the voltage difference is fed to a voltage alteration instruction unit 11. The unit 11 controls so that the amplitudes of the two voltages inputted to the terminals A, B become equal to each other. |
