Speed control for a universal AC/DC motor
US5495161A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jan 5, 1994 |
| Grant date | Feb 27, 1996 |
| Priority date | — |
| Expiry date | Jan 5, 2014 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02P25/145
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A series universal AC/DC motor is controlled by switching the phase angle of an AC signal with a triac power switch in response to a motor control providing a phase-locked loop velocity control. A speed command circuit provides a reference frequency corresponding to a selected motor speed. The reference frequency is compared to a feedback frequency representing actual motor speed. An error signal representing the phase difference between the reference and feedback frequencies is compared to a ramp signal produced by the AC power source, and a resulting trigger pulse is used to control the triac power switch, thereby regulating the speed of the motor.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.