Three-way dimming CFL ballast
US7109665B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Jun 4, 2003 |
| Grant date | Sep 19, 2006 |
| Priority date | — |
| Expiry date | Jun 4, 2023 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S315/04
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A three-way dimming CFL ballast operates at a single high bus voltage while varying switching frequency to control lamp current. The ballast accepts three different light level input switch command positions and an off position to provide three different light output levels. A closed loop current feedback control maintains a precise switching frequency for the ballast to produce accurate light output levels based on the light output switch selection. A reference value is provided to the feedback loop based on the selected light output level to drive the switching frequency at the appropriate value. The ballast circuit provides a sufficient CFL control for three-way dimming as adapted to be used with a standard Edison screw base.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.