Industry Patents
Patent: 7781979
Methods and Apparatus for Controlling Series-Connected LEDs
(Click image for PDF of full patent)
| Patent Number: |
7781979 |
| Title: |
Methods and Apparatus for Controlling Series-Connected LEDs |
| Abstract: |
Methods and apparatus for controlling series-connected LEDs. Two or more
LEDs are connected in series between a first node and a second node,
wherein a series current flows between the nodes when an operating
voltage is applied across the nodes. One or more controllable current
paths are connected in parallel with at least a first LED for at least
partially diverting the series current around at least the first LED. A
controller monitors at least one parameter representative of the
operating voltage, determines a maximum number of the series-connected
LEDs that can be energized by the operating voltage, and controls the
controllable current path(s) so as to increase an amount of the series
current that is diverted around at least the first LED when the maximum
number is less than a total number of all of the LEDs connected in
series. In one example, the foregoing may be implemented as an integrated
circuit package to provide a lighting apparatus suitable for automotive
applications.
|
| Country of Issue: |
US |
| First Named Inventor: |
Lys |
| Assignee: |
Philips SSL |
| Continuation or Divisional of: |
|
| International Classification: |
H05B 37/00 |
| US Classification: |
315/185 S |
| Issue Date: |
08-24-2010 |
| Filing Date: |
11-09-2007 |
| Application : |
11/938051 |
| Notes: |
|
| Link to Patent at freepatentsonline.com: |
7781979 at Freepatentsonline |
| Link to World Patent Family1: |
World Patent Family at European Patent Office |
| Link to Google Patents1: |
7781979 at Google Patents |
1. The Google Patents and World Patent Family links will likely not work until a few weeks
after the patent has issued - they take a while to get new patents in their systems.
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