Nagano Japan shows off yet another contactless charging system
By Joseph L. Flatley 
posted Aug 20th 2009 10:34AM
posted Aug 20th 2009 10:34AM
It's been little over a month since Showa Aircraft demonstrated a contactless charging system that boasts 90% efficiency over a distance of 60 centimeters -- and now what is this? Nagano Japan Radio Co Ltd. is touting a similar system that works up to one meter, with a pretty incredible 95% efficiency at a distance of 40 centimeters. According to Tech-On, the company is currently hard at work trying to ramp the output up from "several tens" of watts to several kilowatts. As opposed to Showa's recent outing (which relies on electromagnetic induction), this system uses magnetic resonance to achieve its effect. However, as this method "drastically lowers" its efficiency when the position of the sending and receiving units are displaced, the team designed a system that automatically detects coil displacement and reorients itself accordingly. The company hopes to someday charge electronic vehicles with the thing, although we'd be happy if it merely enabled us to stow our WildCharge pads out of sight. They seriously clash with the decor here at Engadget HQ.
Nice bracelets
That system looks a bit cumbersome. I don't like it.
Wow, someone "invented" a transformer without iron core and is surprised efficiency goes down. What's next? Tires with non-pressurized air and then complaints that the vehicle is "intermittently behaving erratically"? The solution would probably be to "implement a real-time steering system comprised of multiple CPUs".
Welcome to 2009...
This is not a transformer. I'm not sure what it is, but please don't respond with anger to things you do not understand.
and to engadget... Citation needed. Many people talk about magnet resonance the same way people might talk about light bulbs. But few give technical details of what the heck is going on. Light bulbs are simple. Induction is simple. Transformers... well those are complicated. Magnetic resonance? Just try and look it up. It's right up there with free energy and cold fusion.
Lots of people are very good at Nuclear magnetic resonance. But thats just vibrating magnetic fields with an em pulse. Its not the same thing thats going on here. The closest I can find is a simple, "vibrate this field, and that one starts to vibrate to." and some how its not ac power transmission, or induction. wha?
A free-air inductance system like this operates as an air-core transformer.
@mcbeen,
XFMRs are not that complicated. Quite the opposite in fact. As far as electrical distribution equipment goes, it's pretty simple.
This is indeed just an air-core transformer. Two "conductors" with air replacing the iron core...obviously, the efficiency changes due to the change in permitivity and conductivity of the air in relation to iron...but it still operates under the same basic principles.
Nikola Tesla invented the concept around 1890 to 1910... somewhere around that. This is old technology, its just in refinement now.
Guys, it's not inductance if the coils work when they are perpendicular to each other..... This is something else.
http://web.mit.edu/newsoffice/2007/wireless-0607.html
seems wardriving will get a new meaning soon.
I can feel the radiation already!
only if you have no idea how this works!
@Chris: Are you refering to yourself? Any alternating current produced electromagnetic waves/radiation.
any radiation from devices like these is a drop in the bucket compared to the radiation we're bombarded with on a daily basis. If you don't believe in this "magnetic resonance" that they are claiming and assume it's really just induction...then you should be worried about radiation from transformers, and hell, even your "wireless power" electric toothbrush.
Remains the question as to what frequency this uses, from the size of that coil and practicality it looks like it's lower end of the band though, but then the question is if any modern country would allow a transmitter in the home that broadcasts a hum, and that multiplied by millions of users, it's a freaking nightmare for audio equipment, I bet even cellphone microphones would pick up a constant hmmmmmmmmmmmmmmmmmm though, making communication ever so much fun.
Once cancer rates start going up, the inventors will 'wake up' and say "It seems we have made a slight miscalculation about the safety issues associated with using this technology". What an unfortunate day that will be.
As an EE, I would not be surprised if 50/60 Hz emissions cause cancer after decades of exposure.
If you think that it's that risky aren't you out of your mind sitting there behind a computer?
Didn't Tesla come up with this idea? A long time ago?
but people (like the comment of @Duracel) was afraid of it.
I'm not intimately familiar with Tesla's work, but 95% efficiency at 40cm is pretty neat.
Tesla, at some time, actually came up with every single idea that has been had since.
@rooshma,
AGREED! The man was a certified genius. It's sad that he doesn't get the true credit he deserves. He's up there with Edison in my book.
No tesla used a secret other means, not simply induction, induction was even then old hat already.
Tesla could charge items with pin point accuracy from many many miles away.
Well much of his experiments were a bit unclear, he, as I understand it, had a demonstration where he showed he could transfer power over some distance, something like many (100?) yard if I recall correctly, but there were no details on how it worked and the reports were from witnesses were not that detailed, correct me if I'm wrong, I don't recall reading anywhere it were miles.
Of course since details were lost AFAIK and it became folklore the stories continues to evolve, and might in its original form already be highly exaggerated.
awsome!
Bzzzt!!!
Those Japanese are so clever. They figured out that once coil can induce energy into another. Engadget, how did you get your hands on this? I would think i'd be a closely guarded secret.
Didn't we learn this in 6th grade?
I guess it's the efficiency that's achieved versus the distance that's special, but yeah it does seem a bit pushed as magic.
And just because you can do it in a shielded laboratory doesn't mean it's usable in normal circumstances, what with interference with other equipment and such, I think there's tons of stuff you can do in laboratories in all kinds of fields of technology that you just can't use in a normal home.
Magnetic resonance is electromagnetic induction.
I can make a simpler system than this. Grab a 4' long fluorescent tube and stand under high tension power lines. Under the right conditions, the tube will flicker and light up slightly. Bam! Magnetic resonance in action.
Why does Engadget print articles from people who are showing you the same stuff your electric toothbrush has been silently doing in your bathroom for over a decade? That Wacom tablets have done for over a decade?
Oh yeah, and I forgot, GMs EV1 electric vehicle charged this way too.
Magnetic resonance is not the same as induction. Resonance makes it possible to send power over greater distances than induction with much greater efficiency, as explained in the article.
Both of you are sort of right. Induction via magnetic resonance requires careful tuning of the input signal as a rectangular wave and tuning both the receiving and transmitting inducting coils to the same resonant frequency. This means the energy transmission is more directed and more efficient.
The news here is that we're able to achieve energy transmission with greater efficiency at greater range, and apply the technology to higher-energy applications (possibly). So it's news. Pacemakers and electric toothbrushes maybe have a 80-85% efficiency at distances less than 5 cm; this is a drastic improvement. Flatley may have misrepresented this, though (What is this, FOX? What's with the hype?), and made it seem more revolutionary than it is.
Induction is magnetic resonance. Same thing. You want to say one can be tuned? Either can be tuned, and should be for best efficiency.
And soon, they will be able to get 100% efficiency at 0 cm
Exactly. And Tesla probably has already discovered this.
Not quite. Even at contact, there are always losses.
I know, its just a joke
Edison was a fraud and Tesla did this at 48 kilometers 113 years ago.
Looks to be based on this work out of MIT:
http://www.sciencemag.org/cgi/rapidpdf/1143254?ijkey=94ff.Ay4jRMqU&keytype=ref&siteid=sci
Interesting, that org is in my personal blocklist, not sure why but I'll trust I knew what I was doing.
http://web.mit.edu/newsoffice/2007/wireless-grp1-enlarged.html
happy now?