Lamp end of life (EOL) detection circuit
US8410713B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 7, 2011 |
| Grant date | Apr 2, 2013 |
| Priority date | — |
| Expiry date | Dec 22, 2031 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05B41/2855
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A lamp driver circuit to selectively energize one or more lamps is provided. The inverter circuit has a transformer with primary and secondary windings to provide voltage to the lamps. A filter is connected to the primary winding to receive a primary winding signal representative of the voltage across the primary winding. The primary winding signal has a frequency spectrum and the filter detects a particular characteristic of the frequency spectrum that is indicative of an end of life (EOL) condition of the one or more lamps. A control circuit is connected to the inverter circuit and to the filter. The control circuit is configured to discontinue energizing of the one or more lamps by the inverter circuit when the particular characteristic of the frequency spectrum of the primary winding signal is detected by the filter.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.