| 摘要 |
<p>PURPOSE:To normally and reversely rotate a motor with a simple drive circuit by providing a feedback voltage detecting piezoelectric unit at the position for generating a vibration only for phase A or B. CONSTITUTION:A rotor 2 of ring shape is contacted with one surface of an elastic unit 1 made of metal in a ring shape, and drive piezoelectric units 31-38 and vibration detecting piezoelectric unit 4 are bonded to the other surface. The units 31-34 form a phase A so that the piezoelectric units of positive and negative polarizing directions are used an one period lambda. The units 35-38 form a phase B. A detecting piezoelectric unit 4 having lambda/2 of length is provided at the portion of 3/4 of the unit 1. The unit 4 is contacted with the unit 34 of the end of the phase A, and electrodes 13 are provided at the positions separated by lambda/4 from the center of the unit 4, i.e., from the unit 34. The detected voltage from the electrodes 13 is applied to a phase shifter 10, and the drive voltage of the phases A and B are led.</p> |
