Adaptive variable frequency PWM lamp-using system
US6426569B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 13, 2000 |
| Grant date | Jul 30, 2002 |
| Priority date | — |
| Expiry date | Oct 3, 2020 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02B20/00
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A variable frequency pulse width modulated apparatus and method supplies variable frequency and variable duty cycle power to a load, particularly an electric load of a motor vehicle, and preferably to a filament-type lamp such as a headlight. Which one of the two frequencies are selected is based on a monitored battery parameter, such as a comparison between the current supplied to the battery by an alternator and the current drawn from the battery by a load, with a higher one of the two frequencies being selected when the input current exceeds the output current and the lower frequency being selected when the battery input current is less than the output current. The duty cycle is variably selectable with either first or second pulse width modulated frequency.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.