Ballast circuit for starting fluorescent lamps
US4900986A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 6, 1988 |
| Grant date | Feb 13, 1990 |
| Priority date | — |
| Expiry date | Sep 6, 2008 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S315/02
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An improved ballast circuit for fluorescent lamps includes an electronic bilateral triggering device and a capacitor connected in series combination across the secondary winding output terminals of a ballasting transformer and in shunt with the fluorescent lamps. The triggering device and the capacitor operate to produce high frequency oscillations superimposed on the high AC voltage applied across the lamp cathodes to improve the capacitive coupling between the lamps and their mounting fixture during starting. The triggering device becomes nonconductive to effectively remove itself and the capacitor from the starting circuit while the lamps are lit.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.