What will provide the next technological leap?

[hellokeith]

Originally posted by: BrownTown
First off it is horribly inefficient, second it is dangerous to human health, third it interferes with any other sort of electric circuits you might have.

Have you even given a cursory look to the MIT and subsequent Intel research?

1. 75% efficiency. That's better than some copper wire transmission across a house. And when there is not another resonating coil, NO energy is transmitted or lost.
2. There is no proof to this, any more than high frequency radio signals from cell phones are dangerous.
3. Again, did you look at the MIT research? This technique can go through walls and does NOT interfere with other electronics in different spectrums.

 

[BrownTown]

Originally posted by: hellokeith

Originally posted by: BrownTown
First off it is horribly inefficient, second it is dangerous to human health, third it interferes with any other sort of electric circuits you might have.

Have you even given a cursory look to the MIT and subsequent Intel research?

1. 75% efficiency. That's better than some copper wire transmission across a house. And when there is not another resonating coil, NO energy is transmitted or lost.
2. There is no proof to this, any more than high frequency radio signals from cell phones are dangerous.
3. Again, did you look at the MIT research? This technique can go through walls and does NOT interfere with other electronics in different spectrums.

Well first off, copper transmission over 3 ft is 99.9% efficient, in order to get as crappy as 75% you would have to be going something like 1000 miles (in other words this is several orders of magnitude less efficient). Secondly, any metal object or circuit will be affect by this. If the resonance of any circuit nearby is similar to that of the power source you are gonna fry it. Also, EM radiation is definitely bad for human health, you can argue about cell phones or power lines, but go try and stand next to a high powered radio antenna or in front of a microwave oven and see how you fair. They can try and use a frequency that doesn't interfere with your body, but you can never do it perfectly. Like I said before, people have been doing this for over 100 years, I could go do the exact same experiment MIT did right here. I might not get 75% efficiency, but i guarantee you I could light a 60W bulb from 7ft away, and so could people over a century ago. This is one of the most basic concepts of electromagnetics.

 

[hellokeith]

Originally posted by: BrownTown
Like I said before, people have been doing this for over 100 years, I could go do the exact same experiment MIT did right here. I might not get 75% efficiency, but i guarantee you I could light a 60W bulb from 7ft away, and so could people over a century ago. This is one of the most basic concepts of electromagnetics.

Sigh..

This is Magnetically Coupled Resonance, not magnetic induction. The magnetic fields interact weakly with biological organisms, the circuit fills the space around it with a non-radiative magnetic field oscillating at MHz frequencies.. no people have not been doing this for a century. And if you have ever ran audio equipment, you would obviously know about power loss due to cable length.

 

[PottedMeat]

Interesting effect. I doubt this will ever be more than a short range low power ( less than ~10 feet / less than 100 W ). Instead of having a dozen or so wall warts and comm cables, none. I do like the idea of sealing hand held devices - we could have a small panel on a desk with maybe a range of a foot or so and you could set your device on it for charging, as well as have a short range wireless data connection for data exchange. But they need to improve batteries first for that. I guess you could also use it to transmit power without friction on rotating assemblies. I read on another forum that at 3 feet these coils were highly directional and positions of the people around it dramatically affected the amount of energy tx/rx'd.

I think I'd rather have distributed power or superconducting lines for long range power distribution.

And if you have ever ran audio equipment, you would obviously know about power loss due to cable length.

What does this have to do with magnetically coupled resonance? If you're talking about speaker wire that's due to incorrectly matching conductor gauge with current requirements.



And does anybody have a good basic link to this 'magnetically coupled resonance'? - a quick google search only gives info on that 'wiitricity' stuff and things about imaging.

 

[herm0016]

Originally posted by: hellokeith
And if you have ever ran audio equipment, you would obviously know about power loss due to cable length.

and if you ever ran or designed an antenna or worked with amounts of power over what your house draws you would know that the cable loss is very small over short distances. like BrownTown said, you would have to use a very small conductor over a large distance and a very high current source (heating the wire to a somewhat high temp) to get that low of efficiency.

my 1/2 wave antenna for 2m communication puts out way more than 75% of what i put in because it is designed well and uses the correct cable for a feed line.