Electronic ballast for discharge lamps
US5920155A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 27, 1997 |
| Grant date | Jul 6, 1999 |
| Priority date | — |
| Expiry date | Oct 27, 2017 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S315/04
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An electronic ballast for discharge lamps comprises a main resonance circuit for applying a voltage necessary for operating of a discharge lamp having filaments to both ends of the discharge lamp and a filament resonance circuit for supplying a filament current to the filaments, wherein the main resonance circuit and filament resonance circuit have resonance circuits having different resonance characteristics in an output path leading to the discharge lamp and also change their outputs depending on an operating frequency of switching elements. Thereby a filament current and a voltage across the discharge lamp can be set at suitable one of respective operational modes of the discharge lamp according to an operational state of the discharge lamp.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.