Method and apparatus for LED string short circuit detection and protection
US8907568B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Oct 16, 2012 |
| Grant date | Dec 9, 2014 |
| Priority date | — |
| Expiry date | Dec 20, 2032 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02B20/30
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An apparatus for LED string short circuit detection constituted of: a constant current drive circuit; a plurality of LED strings, a first end of each of the plurality of LED strings coupled to a common output of the constant current drive circuit; a first sense resistor coupled between a second end of each of the plurality of LED strings and a chassis; a second sense resistor coupled between the chassis and a return of the constant current drive circuit; and a comparing circuit arranged to compare the amount of current flow through the first sense resistor with amount of current flow through the second sense resistor, the comparing circuit arranged to assert a fault signal in the event that the amount of current flow through the second sense resistor exceeds the current flow through the first sense resistor by a predetermined minimum value.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.