Remote control of fluorescent lamp ballast using power flow interruption coding with means to maintain filament voltage substantially constant as the lamp voltage decreases
US5107184A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 13, 1990 |
| Grant date | Apr 21, 1992 |
| Priority date | — |
| Expiry date | Aug 13, 2010 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S315/04
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A dimming ballast system wherein the light output of the lamp is controlled by a remote source. The ballast output voltage is regulated by a voltage control feedback loop, the dimming function being achieved by varying the set point of the control loop. The remote control signal, coded by interrupting the current flow to the ballast for a short period, is processed digitally by a microcomputer which generates information to vary the control set point. Circuit means are provided to control the filament voltage of the fluorescent lamps such that as the lamps are dimmed down, the filament voltage is maintained or slightly increased, thus prolonging lamp life and stabilizing the lamp light output.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.