Ballast circuit for compact fluorescent lamp
US5686799A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 8, 1996 |
| Grant date | Nov 11, 1997 |
| Priority date | — |
| Expiry date | Aug 8, 2016 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S315/04
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A compact dimmable fluorescent lamp apparatus that connects with at least one fluorescent lamp and with an input power source that supplies an AC input voltage. The lamp includes a rectification stage for rectifying the AC input voltage, a dimming stage for generating a dimming signal indicative of lamp brightness, and a ballast circuit that is in electrical communication with the rectification stage and the dimming stage. The ballast circuit is arranged for connection with the lamp for applying power variably to the lamp and includes a resonant circuit stage that electrically connects with the lamp and that generates a high frequency voltage in response to the input voltage. The resonant circuit varies the level of power supplied to the lamp in response to the dimming signal, thereby attaining a selected level of lamp brightness. The ballast circuit also includes a voltage feedback element in electrical series with the lamp for generating a selected high frequency voltage signal and for applying this signal to the rectification stage. The feedback element superimposes the ballast circuit high frequency voltage signal over the input voltage.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.