Universal input warm-start linear ballast
US6031342A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 12, 1998 |
| Grant date | Feb 29, 2000 |
| Priority date | — |
| Expiry date | Feb 12, 2018 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S315/07
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An electronic ballast for a fluorescent lamp which includes a frequency sweep circuit for driving a ballast controller IC at different operating frequencies depending on the operating mode of the fluorescent lamp. The sweep circuit monitors the operating mode of the lamp (e.g., preheat, ignite, running, shutdown) and automatically generates an appropriate variable voltage offset for controlling the lamp. The offset is added to a constant voltage supplied to an input of the ballast controller IC, resulting in a corresponding change in the frequency output by the ballast controller IC (and thus the lamp power). The electronic ballast also includes fault protection logic which monitors signals from the lamp resonant circuit and shuts down the ballast in the event of a fault condition. The fault protection logic also resets the frequency sweep circuit so that the lamp can restart automatically when the fault is corrected.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.