Dimming apparatus for fluorescent lamps
US6133697A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Sep 23, 1999 |
| Grant date | Oct 17, 2000 |
| Priority date | — |
| Expiry date | Sep 23, 2019 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S315/04
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
The present invention is to provide a fluorescent lamp dimming apparatus capable of continuously dimming the fluorescent lamp, and capable of eliminating a fluctuation of light outputs, and in particular, capable of turning ON the fluorescent lamp in a low temperature. The fluorescent lamp dimming apparatus is comprised of a lamp voltage detecting circuit for detecting a discharge voltage of the fluorescent lamp, and a control unit intermittently controls the output frequency of a high frequency power supply in such a manner that the output frequency becomes higher than a dimming frequency based on the dimming signal so as to periodically change a current supplied to the fluorescent lamp into a low current; and when the output frequency of the high frequency power supply becomes higher than the dimming frequency, the control unit sets a lower limit dimming set value based upon a detection voltage of the lamp voltage detecting circuit in order that the output frequency of the high frequency power supply is controlled to become lower than, or equal to the upper limit frequency in accordance with the lower limit dimming set value.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.