Control apparatus of fluorescent lamp
US5525870A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 25, 1995 |
| Grant date | Jun 11, 1996 |
| Priority date | — |
| Expiry date | Jan 25, 2015 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S315/05
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A control apparatus for a fluorescent lamp for detecting an end-of-life state of a fluorescent lamp for making it possible to take suitable countermeasures. In the control apparatus, a load circuit is formed of a capacitor connected between filaments of a fluorescent lamp and a choke coil connected in series with the filament, and there are provided a detection coil for detecting a tube current flowing through the load circuit and a detection circuit receiving an output voltage of a rectifier circuit rectifying the output of the detection coil for detecting a rise in the output voltage occurring when the output frequency of an oscillation circuit is modulated by a modulation circuit.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.