Fujitsu Eyes Wireless Gadget Charging For 2012
angry tapir writes "Researchers at Fujitsu Laboratories have developed a wireless charging system that they say can simultaneously charge a variety of portable gadgets over a distance of several centimeters without the need for cables. The system, which will be detailed at a technical conference in Japan this week, could begin appearing in mobile phones and other products as soon as 2012, the company said. Fujitsu's system is based on magnetic resonance in which power can be wirelessly sent between two coils that are tuned to resonate at the same frequency."
You could read the article. The efficiency is 85% at 15cm, and much higher at closer distances, since the efficiency drops off with the cube of the distance.
Is it me, or are people having a hard time believing the technology actually exists?
Two Companies Already Have Products:
http://www.powercastco.com/
http://www.witricity.com/
NY Times Covered this stuff in 2007
http://www.nytimes.com/2007/12/09/magazine/09wirelessenergy.html?_r=1&ref=magazine
Here's CNET demoing powercast's tech in 2007!
http://cnettv.cnet.com/powercast/9742-1_53-25606.html
You can buy full blown evaluation boards online that powercast manufactures that implement wireless electricity:
http://www.futureelectronics.com/en/technologies/development-tools/rf-wireless/Pages/9660812-P1110-EVB.aspx
Why is everyone having such a hard time with this concept?
There definitely needs to be a set standard. I suspect IEEE or another such organization will eventually step up and figure out an agreeable standard.
However, the technology hasn't advanced to the point where it's exactly realistic for most people, or even truly usable. Unless there is a significant breakthrough in the near future, such standardization will probably not happen anytime soon.
"Very" and "No". It's a transformer. There are probably 30 or so in your house right now.
> Worry about your HVAC, laundry machines, refrigerator, home server, incandescent lights, etc.
I did. So I replaced them all, and then added a 12-panel solar array.
My electronics trickle is indeed something that worries me, it's one whole panel.
This is a well-trodden area-- explored by many folks, starting with Tesla. Unfortunately there are several very basic phisical showbunglers if not showstoppers.
Issues that are fundamental to electromagnetic radiation:
(1) If you send out EM waves, the efficiency of the antennas is like 1% at low frequencies, wasting 99.99% of the power. If you use microwave frequencies, the antennas are much more efficient, but so is your body's ability to absorb the stuff, which is not a good thing.
(2) If you try this near-field coupled resonator thing (first tried in 1886), you son find out it has very limited range, and you need coils as large as the distance to be spanned, and the power drops off as the square of the distance when near, as the cube of the distance a little bit farther away.
These are basic Maxwell's equation impediments that are unlikely to ever be overcome.
I modded you up, then thought about it for a sec. I think they're talking about using evanescent waves instead of classical mutual inductance. Evanescent waves separate the near field and far field when modeling antennas, btw.
Here's an article that's heavy on buzzwords but may explain it.
Tiller's Rule: Never use a word in written form that you've only heard and never read. You will end up looking foolish.