Rotation speed control circuit, rotation speed control method and fan system
US8395343B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 20, 2010 |
| Grant date | Mar 12, 2013 |
| Priority date | — |
| Expiry date | Oct 1, 2031 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02P7/29
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A rotation speed control circuit for controlling a rotation speed of a fan includes: a rotation speed detector, for generating a rotation speed voltage according to a rotation speed signal corresponding to the rotation speed; a sample and hold element, coupled to the rotation speed detector, for sampling and storing the rotation speed voltage; an error amplifier, coupled to the sample and hold element, for controlling a voltage of a filter capacitor according to the rotation speed voltage and a reference voltage, to adjust an error voltage; and a pulse width modulation signal generator, coupled to the filter capacitor, for generating a pulse width modulation signal according to the error voltage and a triangle wave.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.