Pulse width modulation speed control
US4371819A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 11, 1980 |
| Grant date | Feb 1, 1983 |
| Priority date | — |
| Expiry date | Dec 11, 2000 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S388/912
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A pulse width modulation (PWM) speed control for a DC electric motor includes an encoder for providing encoder pulses in reponse to incremental rotation of a shaft driven by the motor. A timer senses a time period between encoder pulses. After three consecutive sensed time periods, a microcomputer compares the sensed time periods with a desired time period corresponding to a desired motor speed, and provides a digital value which is a function of the comparison of the sensed and desired time periods. The ditigal value is supplied to a timer, which applies an energizing pulse to the DC motor for an interval which is a function of the digital value.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.