How does this LED light set work?

Discussion in 'General Electronics Chat' started by Garoad, Aug 23, 2012.

  1. Garoad

    Thread Starter New Member

    Apr 24, 2012
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  2. #12

    Expert

    Nov 30, 2010
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    What part of solar cell> batteries> LEDs breaks a rule?

    Hard to imagine a LED setup so dim and flimsy that it can run on batteries?
     
  3. Garoad

    Thread Starter New Member

    Apr 24, 2012
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    Well yeah, they're probably dim as heck. But what I mean is whenever I've put more than a few LEDs in series, it doesn't take many before they don't light at all. How are they getting 100 to stay lit, even dim, on solar power?

    I've always figured the commercial AC powered LEDs only work thanks to the high voltage. So, how is a solar set pulling this off?
     
  4. #12

    Expert

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    Actually, I don't know. It could be done with an inductor, like the Joule Thief, or it could be done with resistors distributed along a 2 wire cable. Each LED could contain its own resistor, or even a programmer of sorts. Really! I've seen leds with primitive intelligence included on the chip. I bet that's what's happening. Smart LEDs.
     
  5. Garoad

    Thread Starter New Member

    Apr 24, 2012
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    Yeah you might be on to something, I have some tiny 3mm slow color changing LEDs. They don't appear to have the usual internal (visible) parts of a regular LED. No idea how they work other than I guess having some kind of micro circuits embedded there somewhere.

    Burned one out with a heat gun once though, so they're sensitive.
     
  6. ErnieM

    AAC Fanatic!

    Apr 24, 2011
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    Outdoor garden solar LED lights have always had a boost inverter, even the single light units. For several reasons they fascinate me so I will buy units just to reverse engineer them to see how they work.

    A white LED takes 3V or so to light, and they run off a 1.2V ni-cad battery. It's common to use an inductor to fly back into the LED which self-regulates the voltage. You could take all 100 LED in series and drive with a flyback boost inductor and get them all to light off a single battery cell.
     
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