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Ultra-efficient LED puts out more power than is pumped in

  1. Mar 10, 2012 #1
  2. jcsd
  3. Mar 10, 2012 #2
    It looks like they're spinning it in the most extravagant possible way. I guess an LED that runs partially off ambient heat is too boring.
     
  4. Mar 10, 2012 #3
    I honestly don't understand why you are questioning the article. They were extremely forthright in explaining that there is no mystical, magical, or new physics explanation necessary.
     
  5. Mar 11, 2012 #4

    Ryan_m_b

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    The article explains pretty well; the energy it draws not only causes the LED to emit photons but also draw heat from the surrounding area for power. It is interesting but this is an extremely small experimental device (it only draws 30 picowatts of power!) and I'm skeptical that it can be scaled up.
     
  6. Mar 11, 2012 #5
    That's what I thought, too. To use a similar percentage of ambient heat in a slightly larger version, I suspect they'd have to alter the shape, in the least. Otherwise, the SA:V probably gets too low. I'm not so concerned with bigger devices, however. I think this could have some interesting applications in nanoengineering, among other things (as has also been stated in the article).
     
  7. Mar 11, 2012 #6
  8. Mar 11, 2012 #7
    Are they? I haven't heard any free-energy crackpottery because of this one, yet.
     
  9. Mar 11, 2012 #8
    I track different boards, its already out there as FE.
    Lack of knowledge can be a dangerous thing. I suspect we will be seeing more of it.
     
  10. Mar 11, 2012 #9

    OmCheeto

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    I have a set of LED xmas lights installed in my kitchen. I got a plug to socket adapter, so I could just flip the light switch to turn them on and off.

    The reason I mention this is because, when I turn the light switch off, the lamps stay on. (Although they are so dim, this experiment has to be done at night.)

    I imagine it is the capacitance of the wires that causes this effect.

    And just as a comparison, I estimate each of my lamps consume ~40,000,000,000 picowatts of energy.

    And 69 picowatts is ~43,500 times less power than the cosmic background radiation per square meter.

    And what did they say?: "The extra energy came instead from lattice vibrations."

    How is this different than, say, how a solar panel works? It has no electrical source, yet generates power. I don't really remember how, but I imagine the effect might be similar.

    My solar panels generates 50 watts of power for $250.
    Doing the math, it would cost $145 billion dollars to get 50 watts worth of extra light from these miracle LED's. (assuming $0.10 per led)

    And god only knows how much land mass 1.45 trillion LED's would take up.

    [Preemptive Edit]I see comments of free energy have popped up since I started my analysis. Send the kooks a link to PF. We do the math, so they don't have to. [/Preemptive Edit] :smile:

    [Postemptive Edit]On second thought, don't send the kooks here. PF might be forced to recruit more mentors to ban the marauding hords.[Postemptive Edit]
     
    Last edited: Mar 11, 2012
  11. Mar 11, 2012 #10

    Ivan Seeking

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    More likely due to temp or capacitance in the LEDs themselves. The capacitance of the wires is miniscule.
     
  12. Mar 11, 2012 #11

    OmCheeto

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    Miniscule? hmmm.... It has been a very, very, long time since I've studied such thing.

    I was thinking that it might be the conductors in the attic, powering the fridge, that might be generating a transformer effect. Only certain bulbs light up in the string. Perhaps I'll invite Janus over tonight, after the sun goes down. Do you know he lives only 3 miles away, and I've never met him?

    But then again, I think I'll wait for the question to pop up in the homework section, before devoting more time to such a trivial problem.
     
  13. Mar 11, 2012 #12

    Ivan Seeking

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    If it is a matter of capacitance, most likely in the transformer for the lights, or the junction temp [I don't know if the temp could be a factor or not], at most the lights will slowly fade to black. If it is induced current, it would be continuous as long as the source of the noise is active. If you are using an electronic controller and not unplugging the light circuit, it could be transistor leakage in the light controller.
     
    Last edited: Mar 11, 2012
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