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Cell Phones Powered By Conversations

Posted by CmdrTaco on from the yakkity-yak dept.

disco_tracy sent in a story about some fancy new power technology designed to tap energy from sound waves. Although the cell phone concept grabs the headline, they also talk about harvesting noise from traffic.

8 of 119 comments (clear)

  1. Infinite power by grapeape · · Score: 4, Funny

    Geez if I could hook up a storage battery and wire it to my wife I could go off grid.

    1. Re:Infinite power by MobileTatsu-NJG · · Score: 4, Funny

      Geez if I could hook up a storage battery and wire it to my wife I could go off grid.

      From what I understand about your wife, she'd use it up again before sunrise.

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      "I like to lick butts!" by MobileTatsu-NJG (#32700246) (Score:5, Informative)

  2. Great by EkriirkE · · Score: 4, Funny

    SORRY I'M YELLING, MY BATTERY IS LOW!!!

    (off-topic lowercase to side-step /. yelling filters here)

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    from 09 F9 11 02 9D 74 E3 5B D8 41 56 C5 63 56 88 C0
    to 45 2F 6E 40 3C DF 10 71 4E 41 DF AA 25 7D 31 3F
  3. Bogus by dtmos · · Score: 5, Informative

    This is a bogus story that wanders around every now and then. Cell phones require hundreds of milliwatts of transmit power, an amount of power far beyond what the human voice can achieve -- even at 100% conversion efficiency.

    1. Re:Bogus by blueg3 · · Score: 5, Informative

      The human voice produces a hell of a lot more power than a cellphone, you can disagree if you want

      Well, a human shouting is about 1 mW. A cell phone's antenna outputs in the ballpark of 250 mW.

      Some quick back-of-the-envelope calculations suggest that if the entire area of a cell phone could pick up sound energy, the ambient sound level was at the pain threshold of 120 dB (1 W/m^w), and it achieved 100% energy conversion, this would generate about 15 mW. For just the 250 mW antenna, this means about 90 minutes of talk time per 24 hours exposure.

      120 dB is very loud, and a far cry from how much sound a phone would normally be exposed to. Note that sound is measured on a logarithmic scale. If the phone was constantly exposed to 60 dB of sound, then it'd only generate 15 nanowatts.

  4. Conservation of Energy by __aajfby9338 · · Score: 4, Insightful

    If only we could harvest energy from articles about operating multi-watt devices from nanowatt energy sources, all of the world's energy problems would be solved.

  5. Hams have done it ... by EABinGA · · Score: 5, Interesting

    A ham operator has built a voice powered radio and has made several long distance contacts with it.

    Details are here

  6. Re:Traffic solution? by Lotana · · Score: 4, Informative

    ...and remember that things powered by the car driving over a power capturing device is stealing gas from your tank indirectly.

    Stealing? Are you trying to troll by attempting to get people outraged that the device powers from the sound generated due to inefficiency of your vehicle?

    It is technically true, the energy of the sound does comes from your fuel tank. But remember that your car would still be expanding just as much energy on generating the noise whether or not there is any sound-gathering device around. Driving on the country road in the middle of nowhere will not increase your fuel efficiency.

    Really the term "stealing" is completely invalid in this case. Now if the headline was about some fancy road surface that converted traction into energy then you would be absolutely correct, because it would adversely affect the performance of your vehicle, thus increasing its energy expenditure, thus stealing from your fuel tank.