Sony Prototype Sends Electricity Through the Air

itwbennett writes "Sony announced Friday that it has developed a prototype power system based on magnetic resonance that can send 'a conventional 100 volt electricity supply over a distance of 50 centimeters to power a 22-inch LCD television.' Unfortunately, Sony's prototype wasted 1/5 of the power fed into it and additional losses 'occurred in circuitry connected to the secondary coil so the original 80 watts of power was cut by roughly a quarter to 60 watts once it had made its way through the system.'"

Comments

Basic physics/electronics fail?

[kheldan]

Why is anyone wasting any time on useless technology like this? Is it based on consumer demand? If so then consumers need some basic physics and electronics lessons. This is not Star Trek, people, we can't "beam" your power to you via subspace, the inverse-square law fully applies, this is not ever going to be efficient or practical! Electrically powered things require power cords, get over it!

Re:Basic physics/electronics fail?

[wronski]

err... its only inverse-square if the energy is unfocused. Since we are talking about a *beam*, this is clearly not the case. The parallel is not exact, but we have known how to transmit EM radiation directionally for decades (what do you think all those parabolic dishes are for?), thereby avoiding inverse-square attenuation; the EM energy is 'beamed' to a receiving antenna, where it induces a current and hence transmits energy. In this case, the trick is constructing a primary coil such that most of the magnetic flux lines that cross it also cross a secondary coil (i.e., it preserves most of the magnectic flux). A AC current on the primary will induce a current in the secondary, and the energy efficiency will be the ratio between the magnectic flux in both coils. Interestingly, if you apply a DC current to one of these coils, you will end up with a very focused electromagnet. You could use it to manipulate a small permanent magnet far away from the coil (on the order of the AC transmission distance), for instance. This sort of remote, non invasive manipulation must have tons of application, from surgical (e.g., guiding a probe to a clogged artery), to military (defusing bombs), to whatever (safecracking anyone?) Anyway, very cool stuff.

So they may be on Tesla's trail. And...?

[ReallyEvilCanine]

Tesla was working on wireless electricity transmission but he was also working on a load of other stuff, all while baking his brain with "health-giving" X-rays. And while Tesla both claimed to have succeeded in wireless transmission and others are purported to have witnessed it, he never once made a claim as to the efficiency which, based on the efficiency of a lot of his other inventions (70% [RMS] for AC, >80% for a coil) was never higher than what Sony's come up with here.

This would be great

[ShooterNeo]

Forget the Sony jokes for a minute. I can think of a great use for this technology : recharging smartphones!

Essentially, if they can miniaturize the receiver coils sufficiently enough, you could pack them so that they are integrated inside the batteries used in a smartphone. (yes, yes, it is somewhat inconvenient to swap the battery in certain Apple phones...)

Imagine the possibilities. You could have one of these transmitters in your car, plugged into the cigarette lighter and stuck between the driver's seat and the cupholders. Another could be on top of your nightstand in your bedroom, or wherever you tend to toss your keys, wallet, and phone at the end of the day. A third one would be in your office on your desk.

If the range is enough (100 centimeters or so) your phone would get recharged while it's still in your pocket! You'd never have to remember to plug it in, and you would be able to use the various power sucking features (games, turn by turn GPS, etc) all you wanted and would almost never run out of battery. It would neatly solve the battery problems with the current generation of smart-phones without having to make the phones bulkier or heavier.

Problems :

1. The receiver coil might take up too much space inside the phone.
2. The range might not be 100 centimeters due to various scaling laws
3. The electromagnetic charging fields might cause biological tissue damage, making it dangerous to use while in your pocket. It might interfere with pacemakers.
4. The fields might wipe credit cards or interfere with electronics in your car or office.

But if these problems aren't that bad, or can be avoided somehow, it would be great!

Re:can we get this tagged

[commodore64_love]

>>>75% efficiency is perfectly acceptable for low power devices.

Then how come the EU and U.S. are banning incandescent bulbs? The latest prototypes using laser-carved filaments operate at just 20 watts, and make the same light as a 15 watt compact fluorescent light. So that's what? 75% efficiency? And yet this is considered unacceptable by the politicians.

I say, if the bulbs are banned for inefficiency, then so too should these over-the-air power transmissions (for the same reason).