Circuitry for driving ultrasonic motor
US4952834A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 10, 1989 |
| Grant date | Aug 28, 1990 |
| Priority date | — |
| Expiry date | Mar 10, 2009 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02N2/147
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
Circuitry for driving an ultrasonic motor in which a rotor is driven by travelling waves generated by a piezoelectric effect, which circuitry includes a pulse generator for generating pulses applied to the ultrasonic motor for driving the same, a driving pulse width changing circuit for changing the width of the driving pulse to change the rotational speed of the motor, a feed-back piezoelectric element provided on the motor for generating a feed-back signal in response to the rotational speed of motor, and a driving frequency automatic tracking circuit responsive to the feed back signal from the motor for generating a voltage signal to control the pulse generator.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.