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DiscoverCircuits.com -- Hobby Corner
Last Updated on:
Tuesday, June 01, 2021 03:06 PM
Hobby Circuits List
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White LED Lifetime
Tests
By: Dave Johnson -- March 1, 2010 |
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Problem: All white LEDs fade over time. I find that some LEDs fade in intensity very rapidly while others fade more slowly but every one I have tested would be worthless in a few months to a year.
Solution: To speed up the
testing process I have modified my constant current LED driver circuit as
shown below. |
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White LED Lifetime Test Circuit |
| This new circuit can test 4 LEDs at the same time. I have
a separate photodiode monitoring the light output from each device. I
have also mounted a battery operated hour meter to the circuit. This
should make it easier to plot light output Vs time curves for several parts. |
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Click Circuit to View PDF |
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Please send comments
to me |
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