| 摘要 |
PROBLEM TO BE SOLVED: To regulate output torque of an ultrasonic motor and to perform continuous low torque operation for a long time. SOLUTION: When a select signal terminal S1 is set to H, FETs 41, 42, 45, 46 are turned on by means of H pulses from terminal (a), (b), (c), (d) so as to let electric current flow in primary side coils 61, 71, and from secondary side coils 63, 73, high voltage level sine wave and cosine wave voltage are impressed to electrodes A, B in an ultrasonic motor. When a select signal terminal S2 is set to H, FETs 43, 44, 47, 48 are turned on by means of H pulses from terminal (a), (b), (c), (d) so as to let electric current flow in primary side coils 62, 72, and from the secondary side coils 63, 73, low voltage level sine wave and cosine wave voltage are impressed to the electrodes A, B in the ultrasonic motor. In this way, the voltage impressed to the ultrasonic motor can be switched between a high level one and a low level one when selection in a signal level of the select signal terminals S1 , S2 is carried out. |
