Fan driver system and analog fan drive chip
US9705439B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Aug 1, 2016 |
| Grant date | Jul 11, 2017 |
| Priority date | — |
| Expiry date | Aug 1, 2036 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02P7/29
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A fan driver system is provided, which includes a PWM generator, a DC generator, a control unit, a pull-down resistor and an integrator. The DC generator generates a DC test voltage, and a voltage of the pull-down resistor is detected to generate a determination signal. The PWM generator provides first and second PWM test signals having different duty cycles to the fan, respectively. The integrator integrates speed signal from the fan and corresponding to the first PWM test signal, to output a first integral signal, and integrates the speed signal corresponding to the second PWM test signal, to output a second integral signal. According to the first and second integral signals, and the determination signal, the control unit drives the PWM generator to selectively provide PWM working signal to the fan, and drive the DC generator to provide DC working voltage to the fan.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.