Wireless energy transfer over several feet at 50% efficiency

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Gary
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Wireless energy transfer over several feet at 50% efficiency

Post by Gary » Fri Aug 03, 2007 12:57 pm

Just heard a guy (Graduate student in physics at MIT, Andre Course (sp?)) on National Public Radio talking about recent research. They are now able to light up a 60 watt light bulb about 8' away from a wireless power source.

He claims the new technology will have a conservative efficiency of 50% and is good for a few hundreds of watts. It uses device coils of about 12" radius for sending and recieving. The frequency is between 1 and 10 mhz. The trick he says, is like swinging on a swing. You get the same resonence between the coils and you get good efficency of energy transfer.

Funding is from the US government through MIT and the "Institute for Soldier Infastructure".

Possible concerns are the affect of magnetic fields on living things, but present levels used in research seem to be within the guidelines.

Looks like very exciting research. Although the report was short and without a lot of detail. Could have many implications including charging cell phones, portable computers and other battery powered items. Maybe this is what Tesla was trying to get working.

It all sounds a little too easy. Why hasn't this been done before? I figure there are health concerns. My dad was an air traffic controller and ham operator since WWII :grin: , and was exposed to a lot of RF energy. He's in his 80's now and has a kind of slow acting leukemia.

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haklesup
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Post by haklesup » Fri Aug 03, 2007 3:16 pm

I have seen some chatter in the press about that. Seems the new tech uses magnetic fields only while previous attempts used EM waves.

Anyway. I can't see this being used as a general purpose extension cord for lighting but for recharging wrieless/cordelss devices or powering computer peripherals it might find a home. For military, I can see lots of uses because if they want to ignore an exposure spec, they will. Imagine a truck mounted generator that powers the backbacks on the foot soldgers. No more heavy batteries.

Consumer acceptance will be rough. Lots of people distrust strong fields as being somehow unsafe.

Robert Reed
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Post by Robert Reed » Fri Aug 03, 2007 4:34 pm

"They are now able to light up a 60 watt light bulb about 8' away from a wireless power source. "

Long live Tesla - today a light bulb, tomorrow the whole city! :grin: ( I have seen radio techs in the past impress their clientle by holding 40 watt flourescent bulbs near a VHF Quarter wave whip, key the transmitter and light them up. Pretty impressive when done in a dark garage. But I assume your post was in regards to incandescent lamps - a whole different story).

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Chris Smith
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Post by Chris Smith » Fri Aug 03, 2007 7:52 pm

Tesla did all this at the turn of the last century.

He lit up over 10,000 watts at 20 miles, and just so happened he also burned down the power station in Colorado.

That was 1910 I believe?

I have made the Tesla Coil light up a twin 40 at 8 feet, which is easy.

Gary
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Post by Gary » Sat Aug 04, 2007 6:10 pm

Robert Reed wrote:" I assume your post was in regards to incandescent lamps -
Correct.

I was also forwarded (this week) an unrelated video of a guy putting water and salt into a test tube. When exposed to RF energy, it released oxygen and hydrogen gas and put out a flame several inches tall. I doubt they were worried about energy efficiency however, and made no comments regarding the net energy released (if any). A fellow co-worker thought it was going to make the guy rich, but they seemed to be jumping to conclusions. Not understanding the physics. Electrolysis has been around for a long time and the idea of a gas tank full of water is an urban myth IMHO.

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Chris Smith
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Post by Chris Smith » Sat Aug 04, 2007 9:30 pm

Tesla did his 10,000 watt trick long before fluro was even popular.

His light up was resistive power, and at the turn of the last century.

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jollyrgr
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Post by jollyrgr » Tue Aug 07, 2007 10:16 pm

This is nothing new. In fact you can get wireless extension cords for $35 that operate in the unlicensed 7.2 GHz band. Range is UP TO 300 feet. Just don't stand or put anything in between the base and client antennas!

These are great for powering objects in shed out back without having to run a long extesion cord. They also work great for beaming power from an outdoor outlet up to kids tree houses. Running an electric weed whacker is problematic as you need to keep adjusting the antennas.

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haklesup
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Post by haklesup » Wed Aug 08, 2007 11:08 am

Good Grief, that was last years April Fools Joke. :grin: :razz:

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jollyrgr
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Post by jollyrgr » Wed Aug 08, 2007 4:42 pm

haklesup wrote:Good Grief, that was last years April Fools Joke. :grin: :razz:
Heh heh heh heh.

I still manage to get people with that one. And I still plan on making a set of these when I find a trashed x10 video/audio Transmitter and Receiver.
No trees were harmed in the creation of this message. But billions of electrons, photons, and electromagnetic waves were terribly inconvenienced!

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