| 摘要 |
PURPOSE:To obtain a driver for an ultrasonic motor having a simple structure and easy reductions in size and weight by providing an oscillator for generating an AC electric signal, transformers in first and second excitation sources, and setting turn ratios between primary and secondary sides of the transformer at 1:n (n>=1). CONSTITUTION:Two output terminals are provided at an oscillator 61 for generating an AC electric signal having an arbitrary frequency, one is connected directly to a first booster transformer 62a and the other is connected to a second booster transformer 62b through a phase shifter 63 and a phase shift inverter 64. Turn radios between primary and secondary sides of the transformer 62a, 62b are set at 1:n, n>=1 to raise the voltage amplitude on the secondary side to a level sufficient to drive an ultrasonic motor. In the motor, its driving frequency is generally 20kHz-several hundreds kHz, and its driving current is small due to high driving efficiency. Accordingly, the shapes and sizes of the transformers 62a, 62b can be remarkably reduced. |
