Motor drive device and cooling device using the same
US7796867B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 23, 2006 |
| Grant date | Sep 14, 2010 |
| Priority date | — |
| Expiry date | May 14, 2027 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03K2017/0806
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A drive circuit of a fan motor is provided. In an embodiment of the drive circuit, a first PWM comparator compares a temperature detection voltage with a cyclic voltage, and outputs a first PWM signal. A second PWM comparator compares a minimum frequency setting voltage indicating a minimum frequency of the fan motor, with the cyclic voltage, and outputs a second PWM signal. The drive circuit combines the first PWM signal and the second PWM signal by a logical operation, to drive the fan motor. The drive circuit includes a first logic gate which generates a logical sum of the first PWM signal and the second PWM signal, and a second logic gate which generates a logical product of the first PWM signal and an inverted signal of the second PWM signal. The drive circuit switches drive mode based on the first logic gate and the second logic gate.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.