Load and supply voltage sensitive speed control system for DC brushless fan motors
US5563480A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Feb 21, 1995 |
| Grant date | Oct 8, 1996 |
| Priority date | — |
| Expiry date | Feb 21, 2015 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG05D23/1906
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
A speed control system for brushless DC motors which maintains the rotational speed of the motor substantially constant even when the motor load and/or supply voltage fluctuates. Furthermore, by including a negative-resistance temperature coefficient thermistor in the speed control system, the rotational speed of the brushless DC motor may be varied as a function of ambient temperature. Thus, if the brushless DC motor is part of a motor fan and there is an increase in the ambient temperature, the rotational speed of the motor will increase to provide additional cooling. In contrast, if the ambient temperature decreases, the rotational speed of the brushless DC motor will be reduced thereby resulting in quieter operation of the motor.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.