Control device for ultrasonic motor
US5173630A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 6, 1991 |
| Grant date | Dec 22, 1992 |
| Priority date | — |
| Expiry date | Mar 6, 2011 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02N2/062
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A control device for an ultrasonic motor which is suitable for use in controlling the speed of the ultrasonic motor includes an oscillator for generating drive signals of a resonant frequency of the ultrasonic motor; and a drive signal restricting device for turning on and off the drive signals at a fixed duty ratio. The control device further includes a counter in which counted results of the counter are incremented by a first pulse signal whose frequency increases as a target speed of the ultrasonic motor increases, and in which the counted results are decremented by a second pulse signal whose frequency increases as a travel speed of the ultrasonic motor increases; and a duty ratio setting device for causing the duty ratio to increase as the counted results of the counter increase.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.