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Pushing 800W of Wireless Power at 5 Meters

Posted by timothy on from the distance-rocks dept.

Joe Decker writes "The Nevada Lightning Laboratory has experimented with Nicola Tesla's methods of wireless power transmission to push 800 Watts over 5 meters, besting MITs mark of 60W over 2 meters last year. (May I dream of wireless laptop power? I hate power cords.)"

6 of 397 comments (clear)

  1. more interesting: Self-Powered 'Automatons.' by prgrmr · · Score: 4, Interesting

    This unit collects energy from the ambient electric fields using an on-board 'reverse Tesla Coil,' which in turn charges a large, on-board capacitor bank. The capacitors then drive a DC motor connected to one of the wheels, providing motive effort for the machine.

    I wonder how much ambient electricity can be captured in a large city as an alternate means of powering an electric car?

    1. Re:more interesting: Self-Powered 'Automatons.' by smellsofbikes · · Score: 5, Interesting

      People who live near (under) high-voltage cross-country power lines can tell you about harvesting electric fields. People have been known to run wires through their attics, parallel to adjacent high-voltage lines, and run lights off them. It's considered power theft, which I think is a shame, because it helps make the rest of the house a little more liveable, with fewer shocks from touching light switches or heating vents.
      In Moab, Utah, there's a popular bike trail with the parking area right under a major power line. There are audible snapping and popping sounds coming from bikes on car-top racks. I keep meaning to wire up a capacitor bank and see how far it charges up while I'm out on a ride, but I haven't had time yet to build that.

      --
      Nostalgia's not what it used to be.
    2. Re:more interesting: Self-Powered 'Automatons.' by KnightElite · · Score: 4, Interesting

      Apparently a farmer near the town of Estevan, Saskatchewan, got in trouble with the law for doing something like this. He was only a few miles from the powerplant and built a shed with a large transformer in it underneath the high voltage lines and pulled power from it to run parts of his farm. From what I heard, he did this for several years before being caught.

  2. Re:Lets think about this for a while by jonnythan · · Score: 4, Interesting

    Hate to break it to you, but you're bathed in much more than a few millitwatts of EM every second of every day.

    Think about the 50,000 watt AM antenna you drive by on the way to work. The hundreds of multiple-watt in-use cell phones you walk by every day. The Wi-Fi in your office and your local Starbucks.

    You're bathed in all sorts of EM radiation all the time. You can't get away from it.

  3. Wireless power + laptop == bad by Taxilian · · Score: 5, Interesting

    Another problem that any physics professor will tell you (after pointing out that "the boys" are not going to be in any more danger from that than they are from your cell phone, since neither would be likely to operate at a frequency at which the human body is resonant) is that any bit of metal can act as an antenna. All it takes is to have one piece of wire inside your laptop that happens to be the right resonant frequency for the power that is being transmitted and ZAP! I for one would not want my sensitive electronics that can be fried by static electricity in the wrong place to be anywhere near something like that.

  4. Re:it would help if you understood the physics her by srmalloy · · Score: 4, Interesting

    Of course, this being Slashdot, it's not surprising that most posters never RTFAed and post nonsense "it's just like an inductive transformer" (nope, those don't use resonance) or "it's just like an antenna" (nope, that is radiative transfer) or "Tesla looked at this a century ago" (nope, people like Tesla were concerned with power transfer over long distances, which necessitates radiative mechanisms and hence low efficiency).

    It's a pity that your handwave of the "Tesla looked at this a century ago" opinion falls so flat by proving that you, yourself, did not RTFA, or you would have seen the third paragraph of the article, which states "Intriguing as this might be, we have no plans to pursue intellectual property for this discovery. The concept of using resonant coils to wirelessly couple power was patented by Nikola Tesla over 100 years ago." Shooting your argument in the foot by demonstrating that you are a member of the population you rail against does little for your credibility.