Adaptive synchronous DC fan speed controller
US6381406B1 · kind B1 · utility
31Cited by
7References
12Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Mar 2, 2001 |
| Grant date | Apr 30, 2002 |
| Priority date | — |
| Expiry date | Mar 2, 2021 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02P23/186
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A method and apparatus for controlling the speed of a voltage-controlled fan by locking the pulse-width modulated speed control voltage to a tachometer signal of the fan is presented. By triggering the off time of the PWM pulse to the detection of the tachometer signal and ensuring the off time is less than one tachometer period, no phase and frequency information is lost.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.