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Wireless power transmission test video

Discussion in 'Energy, Environment, and Policy' started by vfx, Oct 6, 2009.

  1. vfx

    vfx Well-Known Member

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  2. mt2

    mt2 Member

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    Tesla was right!!
     
  3. dpeilow

    dpeilow Moderator

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    Crystal radio, anyone?
     
  4. AntronX

    AntronX Member

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    Ugh! I wish all those wireless power people would just go away. They bother me about the same as those flywheel / free energy scamsters.
     
  5. bolosky

    bolosky Member

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    Let's do a little math. The surface of a 4.1km radius sphere (=4 pi r^2) is about 211 million m^2. If the transmitter is putting out 50kW then the flux at 4.1km is 50kW/211 million m^2 = 0.2 mW/m^2. He's clearly not covering a square meter of air, so he's probably generating a few tens of microwatts.

    Solar flux at earth orbit is 1.4kW/m^2 (I think, I'm getting that number from memory). Lots of that is lost in the atmosphere, and half of it happens at night, plus Seattle's at 47 degrees latitude, so it loses some due to the light coming in at an angle. Say that 10% makes it to his rooftop, averaged over a year. That's still 140W/m^2, or a little less than a million times the RF he's getting. So using a standard calculator-style solar cell and some storage to handle night (probably a cheap capacitor, since it doesn't have the charge/discharge lifecyle problems that batteries do and would be storing only a couple of joules total) would be a much more sensible solution.

    But, as stunts go, it's still pretty cool.
     
  6. Takumi

    Takumi Member

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    Antron, wireless power is different from that of the "free energy scamsters." Solar is actually a part of the electromagnetic spectrum. I may be simplifying it too much, but just as we are learning to harness the sun's energy, it is only a part of that spectrum.

    More:
    Eric Giler demos wireless electricity | Video on TED.com
     
  7. AntronX

    AntronX Member

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    There is nothing (that I know of) that can beat the efficiency of energy transit through the wire. When wireless gets up to 90 - 97% efficiency, then it's good. Too bad it will not, for any practical distances to replace power lines. Using it to "wirelessly" charge your gadget by placing your gadget on a coil is not wireless, but more like plug-less.
     
  8. doug

    doug Administrator / Head Moderator

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    I agree with you Anton. But the emphasis here is different. The point is that the devices use so little power than they can run off radio waves in the air. As dpeilow says, it's like the crystal radio kits we used to build as kids. You could listen to the radio with no internal power of amplification.

    Not that it's terribly practical, but it is a neat trick.
     
  9. dpeilow

    dpeilow Moderator

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    Sony introduce a wireless power system

    Well known scamsters, Sony :biggrin:
     
  10. AntronX

    AntronX Member

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    Yea, great. Lets waste more energy on solutions to non-problems. Your TV that use to consume 60 Watts now will use 100 Watts, 67% more energy because Sony wants to sell more useless things and people will buy into this not knowing any better. This is a neat trick, but I hope it stays just a trick.
     
  11. Tdave

    Tdave Member

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    No kidding. I can't think of a bigger waste of energy than this. What a huge step back in efficiency.
     
  12. vfx

    vfx Well-Known Member

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    I had a landlord whose rabbit would eat through every exposed wire in the house -and there are a lot of them in a house. She would love this.

    I would wonder if it would bake the rabbit? :rolleyes:
     
  13. doug

    doug Administrator / Head Moderator

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    I don't think it makes a whole lot of sense for a stationary, semi-permanent installation like a wall mounted TV set. Run the power in the wall if you really want that clean look. I can see the convenience factor for certain devices, though. Palm Pre is an example.
     

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