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What is the Future of Wireless Power?

mfbatzap writes "According to Firdooze, we have seen various devices that can free ourselves from wires at CES 2008. The manufactures, Wildcharge, Powercast and Fulton Innovation, came out with two different methods of transmitting power from source to the devices. Wildcharge and Fulton banked on magnetic coupling while Powercast decided to go with RF (Radio Frequency). So which technology will eventually prevail to be the future of wireless power? Or will the technological setbacks from transferring power wirelessly make it unrealistic to accomplish a wire-free world?"

5 of 178 comments (clear)

  1. Re:Out of curiousity... by tjstork · · Score: 4, Informative

    All fuels take more energy to produce... in a sense, our present fossil fuel predicament is because we are using stored energy from the sun over millions of years. That we can even think about creating biofuels or really, any sort of fuel, efficiently, says a lot for how far the technology has come. But we'll never be able to just "create" a fuel, and the world's going to have to accept that.

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  2. Re:Out of curiousity... by MBCook · · Score: 3, Informative

    I'd think you'd have problems with RF, it'd be easy to waste power that way. The magnetic people mentioned in the article say they've hit 98.5%, which is great.

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  3. Re:I say neither, you say neither by Lumpy · · Score: 3, Informative

    you dont need to shoot it across the room, just charge the device when set on a table. Make ALL your tables charging stations and now you attain the "wireless power" illusion.

    I did this way back in the 90's for one of my EE projects. I created a charge mat and charge adapters to make devices charge from the mat. worked great, erased tapes , credit cards, and discs though... All you did was set the device down and it started charging. worked great and could supply 100ma of charge current to 3 devices.

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  4. omnidirectional wireless power by sluke · · Score: 5, Informative

    I'm relatively pessimistic about both of the technologies mentioned due to the inherent limitations that they pose (large leakage of radiated power or short range). I'm looking forward to seeing products based on the wireless power idea that came out of the Joannopoulos group at MIT in 2006.
    The idea was that you can setup an RF wireless power transmitter in such a way that it does not actually transmit any power unless it resonantly couples to a precisely shaped receiver. This way there is little to no leakage and they claimed that the power transfer was quite efficient. I'm sure this was posted to slashdot, but I can't seem to find it. Here's a link to the paper if you are somewhere with access to Science: Science 6 July 2007: Vol. 317. no. 5834, pp. 83 - 86 and here's a link to the press release by the MIT news office (no subscriptions required).

    1. Re:omnidirectional wireless power by Big_Breaker · · Score: 3, Informative

      Sorry but you have this one wrong - converting mains AC to 1mhz is very easy. A common switch mode power supply chops the 50/60hz AC from the wall into a 100khz to 1Mhz waveform with a common (but fast) MOSFET. The chopped signal is then run through a stepdown transformer. The transformer and ripple filtering capacitors in the second stage can be MUCH smaller and more efficient due to the higher input frequency. In this way the high frequency generation is effectively free for a wireless power system, since most DC converter will have a high frequency first stage anyway.

      The resonant coupling is the hard part. Switch mode frequency chopping is bog standard.