LED chain failure detection
US7876103B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 27, 2008 |
| Grant date | Jan 25, 2011 |
| Priority date | — |
| Expiry date | Jan 6, 2029 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02B20/30
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
The system consists of an LED failure detection circuit to provide protection against individual LED catastrophic failure. When LED clusters are arranged in a series-parallel configuration, it is important to detect individual LED failure in order to avoid uncontrolled luminous intensity reduction and/or light uniformity degradation. The circuit compares the voltage levels on LEDs with similar position but situated in different chains. In normal conditions, the voltage levels are substantially similar to one another. In case of individual or multiple LED failure, open or shortcircuit, the circuit sends a signal to the automatic turn off circuit that initiates the lamp forced turn off sequence.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.