Fixed operating frequency inverter for cold cathode fluorescent lamp having strike frequency adjusted by voltage to current phase relationship
US7294974B2 · kind B2 · utility
1Cited by
67References
8Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Feb 16, 2005 |
| Grant date | Nov 13, 2007 |
| Priority date | — |
| Expiry date | Feb 20, 2025 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S315/07
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A method of driving a lamp that uses a DC to AC inverter that is connected to a primary winding of a transformer is disclosed. The inverter frequency is variable, and in one embodiment, may be controlled by a voltage controlled oscillator. Circuitry is included that monitors the phase relationship between a voltage across a secondary of the transformer and a current through the primary of the transformer. The circuitry monitors the phase relationship and adjusts the inverter frequency, such as by adjusting voltage controlled oscillator, so that the phase relationship is maintained at a predetermined relationship.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.