Dimming control of electronic ballasts
US6486615B2 · kind B2 · utility
26Cited by
12References
12Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Oct 13, 1998 |
| Grant date | Nov 26, 2002 |
| Priority date | — |
| Expiry date | Oct 13, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05B41/3927
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
The invention provides an apparatus and a method for controlling the power output of a fluorescent lamp in order to provide dimming control. The fluorescent lamp is driven by an electronic ballast, for example a half-bridge resonant inverter, and the electronic ballast is switched at a constant frequency and with a constant duty-cycle, but with a variable DC voltage power input. Dimming control is provided by variation of the DC voltage power supply. The variable DC supply may be obtained from an AC source followed by a power factor corrected AC-DC variable converter, or a DC source followed by a variable DC—DC converter.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.