LED driver with end-of-life detection circuitry
US8853949B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 20, 2011 |
| Grant date | Oct 7, 2014 |
| Priority date | — |
| Expiry date | Jun 9, 2032 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02B20/30
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An LED lighting device includes a DC/DC power converter having output terminals coupled to respective lamp sockets. A controller receives signals from a current sensor and a voltage sensor, and controls the DC/DC power converter to increase/decrease an output voltage based on a sensed output current with respect to a target value. A sensed output voltage is compared to predetermined upper and lower limit values, and the DC/DC power converter is disabled when the output voltage exceeds the predetermined upper limit value or falls below the predetermined lower limit. The controller further measures an accumulated lighting time of the device, and after the accumulated lighting time has exceeded a predetermined switching time, decreases the upper limit value monotonously or in increments as the accumulated lighting time passes.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.