Control circuit for a fan
US7541762B2 · kind B2 · utility
Assignees
Inventors
Key dates
| Filing date | Dec 15, 2006 |
| Grant date | Jun 2, 2009 |
| Priority date | — |
| Expiry date | Apr 15, 2027 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F1/206
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A control circuit for controlling rotational speed of a fan for an electronic device includes a temperature detecting unit for detecting an ambient temperature of the electronic device, and outputting a corresponding detection result; a control unit receiving the detection result from the temperature detecting unit, and outputting a corresponding control signal; and an operational unit receiving one or both of the control signal from the control unit and a pulse-width modulation (PWM) signal, and outputting a backup control signal for controlling the rotational speed of the fan, so that the fan can continue operating when needed, even if the PWM signal disappears.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.