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Electrical power

  1. Jul 29, 2004 #1
    me and my dad were having a conversation about nikola tesla last night and he was saying how todays world needs to invent a wierless source of electrical energy. Kind of like radio, but instead of getting a weak electromagnetic signal, you would get a strong powerful signal that could maybe power a car. My question is, why cant we do that? :confused:
  2. jcsd
  3. Jul 29, 2004 #2


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    If you could generate the fields to allow that kind of power output, we would have to stop making things out of metal. What if all your coat hangers started carrying 4 amps at 110V?

    Most of this power would be wasted anyway. It would be beamed into space or into the ground.

    There are ways to use "beamed" energy on a small scale. All antennae rebroadcast their signals. Your radio actually acts as a weak transmitter for any station to which you are tuned. What you could do, is alternate a querrying pulse with a power pulse.

    You would need a high-power phased array source, and a low power phased array reciever. (A phased array is capable of generating a fairly narrow beam of radio waves).

    First, the transmitter sends out a querrying pulse. This is a low power omnidirectional EM wave. Your local phased array detects that part of the radiation directed toward it, and rebroadcasts it to the transmitter. The transmitter detects the return signal, and uses the phased array to send an amplified mirror image pulse back to you. This amplified signal is enough to run your appliance.

    It would be prohibitively expensive, and would only work with line of sight, but many materials would be transparent to the signals involved.

  4. Jul 29, 2004 #3
    4 amps in coathangers..... You could have nice warm clothes to put on in winter!
  5. Jul 30, 2004 #4


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    You'll definately need something to cover up the third degree burns!
  6. Jul 30, 2004 #5
    thanx guys.
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