Low power fan drive circuit for personal computers
US5469320A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 29, 1993 |
| Grant date | Nov 21, 1995 |
| Priority date | — |
| Expiry date | Oct 29, 2013 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG05D23/24
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
An efficient fan drive circuit to drive a variable fan used in a power supply of a personal computer system. The fan drive circuit uses a diode to establish the minimum fan speed during operation in the normal temperature range. The bleeder resistor normally coupled between the fan and a negative output voltage is removed and replaced with a current source. The current source also serves to shut down the power supply if the fan is not operating properly or is not installed. A shut down circuit remains to shut down the power supply when excessive temperature occurs, or when the current source detects that the fan is malfunctioning or not installed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.