High frequency electronic ballast
US6696800B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 20, 2002 |
| Grant date | Feb 24, 2004 |
| Priority date | — |
| Expiry date | Dec 20, 2022 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05B41/2928
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A method and ballast for driving a high intensity discharge (HID) lamp include generating a very high frequency driving signal for the HID lamp, generating a low frequency modulating signal, amplitude modulating the driving signal with the modulating signal at a predetermined low initial modulation level, measuring a lamp voltage across the HID lamp, determining a standard deviation of the lamp voltage, comparing the standard deviation with a predetermined minimum level, if the standard deviation is above the predetermined minimum level, incrementally increasing the modulation level and repeating the amplitude modulating step, the measuring step, the determining step and the comparing step, and if the standard deviation is below the predetermined minimum level, maintaining the amplitude modulation at the determined level.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.