Thursday, October 14, 2010

Examples of Failures of LEDs

While driving around this morning, I noticed a few LED arrarys in traffic lights that are dying:  one red light, and two green lights.  Each light has patches that were dark, and patches that were flickering at various states of brightness.

Besides wondering what the heck is causing these LEDs to die in this way (could it be a ban on lead solder?), these lights have caused me to ask another question:  Is LED lighting really ready to take the place of incandescents?

I currently rent my home, and both finances and space are tight for me.  Thus, stockpiling incandescent lights are impractical at this moment.  I hate fluorescent lights, so I have hopes that LEDs will be ready and affordable after incandescent lights are banned.  And while I expect that the Free Market will win in the end, we, unfortunately do not have a Free Market--as illustrated by the ban of incandescent light bulbs.

But seeing these lights flicker have caused me to wonder:  will the LED lights really last as long as claimed?  We already know that fluorescent lights don't--turning them on and off like we do incandescents are abusive to those lights, as is putting them in enclosures and in ceiling fans.

We really should let the Free Market work these details out!

3 comments:

  1. Sounds like the backplane or the connections were failing, especially the flickering and the way whole sections failed.

    LEDs themselves are pretty mature technology, and their lifespan and failure modes are pretty well understood.

    (They are, after all, a simple diode and reflector...)

    This highlights that there's more to "LED lights" than the LED itself.

    Good high-end LED systems will have an electronic controller (such as in any good LED flashlight), and all systems will have appropriate voltage and current conversion systems if they're made to run off of household power.

    Likewise they all have some sort of physical and electrical backplane, which is subject to environmental and physical stresses.

    Traffic lights are subject to a lot of movement, temperature change, and exposure to moisture.

    (I would not, however, blame a lack of lead in solder. Lead-free solders can have various issues, but they're pretty well understood by now, and I don't think any of the issues are likely to be relevant in an LED array anyway.)

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  2. That analysis sounds reasonable to me; indeed, I'd expect indoor lights to have less of a failure rate than outdoor lights. Even so, there are going to be certain types of problems that can only be discovered by prolong, large-scale use, and by banning incandescents, we'll be forced to be guinea pigs for this new technology.

    Having said that, I think LED lighting is a fantastic concept, and I look forward to the technology being refined over the years!

    My other concern to banning incandescents, though, is that it will lessen the pressure to reduce the price. While the price of LED lights will undoubtedly go down over time, it wouldn't hurt to have super-cheap tungsten bulbs as an example to compete against.

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  3. Totally agree on the political aspects. I was only addressing the technical ones, because, well, they're more interesting to me.

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