Circuit and method for driving light emitting diodes
US8049690B2 · kind B2 · utility
2Cited by
1References
20Claims
0Family size
Assignee
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Key dates
| Filing date | Apr 18, 2008 |
| Grant date | Nov 1, 2011 |
| Priority date | — |
| Expiry date | Sep 1, 2030 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05B45/38
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A circuit and a method for driving light emitting diodes (LEDs) are provided. First, an input voltage is converted into an output voltage and the output voltage is transmitted to the anode terminals of LED strings. The output voltage is reduced when the output voltage is greater than a first threshold voltage and the output voltage is reduced when the lowest level among the cathode terminal voltages of all the LED strings is greater than a second threshold voltage. Thus, the output voltage can be maintained at a lower level for driving all the LED strings to reduce unnecessary power wastage.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.