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MIT Wirelessly Powers a Lightbulb
kcurtis writes "According to the Boston Globe, MIT Researchers have powered a light bulb remotely. The successful experiment lit a 60-watt light bulb from a power source two meters away, with no physical connection between the power source and the light bulb. Details about WiTricity, or wireless electricity, are scheduled to be reported today in Science Express, the advance online publication of the journal Science, the Massachusetts Institute of Technology said. 'The team from MIT is not the first group to suggest wireless energy transfer. Nineteenth-century physicist and engineer Nikola Tesla experimented with long-range wireless energy transfer, but his most ambitious attempt - the 29m high aerial known as Wardenclyffe Tower, in New York - failed when he ran out of money. Others have worked on highly directional mechanisms of energy transfer such as lasers. However, unlike the MIT work, these require an uninterrupted line of sight, and are therefore not good for powering objects around the home.'"
This just screams cancer. I Hope I don't unwittingly end up sitting between the device and the energy transmitter of one of these things.
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http://www.youtube.com/watch?v=90YsTGklRqA
Hell, back in the 60s, I had a monstrous WWII surplus transmitter, a BC-610 by name. This thing was the size of a large washing machine, and had vacuum tubes in it the size of your head. It would produce a vertiable torrent of RF. As a young ham operator, I was a little sketchy on the principles and practice of proper antenna load and impedance matching, so the whole feedline was radiating, and causing standing waves in all of the house wiring...in my house and the houses around ours. Enough power was intercepted by house wiring that the incandescent bulbs in light fixtures would glow dimly when I was on the air...even though they were turned off. You could hear my voice on telephones for approximately 10 houses radius, since non-linearities in the old phones were enough of a rectifier to do AM detection on the signal the phoen wiring picked up. Fluorescent tubes in my house & my immediate neighbours would light with a strange plasma looking pattern, caused by the structure of the standing waves present. And forget watching TV or listening to the radio in the neighborhood - my voice was heard on radios louder than the program material, and TV pictures were obliterated by a dancing pattern of hum bars. Enough complaining got back to my parents that I could only operate late late late at night....anyway, you can see why I am not that impressed with the concept of wireless power transmission...I did it in person over 40 years ago...
There is no God, and Dirac is his prophet.
Wacom are powering their tablet pens and mice wirelessly via simple electromagnetic induction. And they patented the hell out of it.
Just saying.
The major breakthrough though is the ability to select which device will be powered. Tesla did nothing of the sort and just created wild electromagnetic fields which then were no big deal but now would render some equipment useless and additionally destroy some other equipment. The resonating frequency in this case can be much lower and thus less volatile, but when "stacked" it still produces the same result.
Well, back to rejecting software patent applications.
I came across this technology completely serendipitously a few weeks ago on How Things Work. There was a link to "wireless electricity" off the main page and I followed it and they discussed the MIT patents and I downloaded several different patents in the field. They were all from within the last few years and involved resonance coupled with induction.
What surprised me was the lack of imagination in the applications. They were talking about remotely recharging cell phones and MP3 players or letting you move around electronics without needing to find a plug. Well those are all fine ideas and quite obvious indeed but I saw nothing about the one area that seemed to potentially benefit the most from this: robotics.
All the pieces are there in robotics except for the one that this technology addresses: lightweight, high-density power. Oh, and let's not forget cheap.
Powering the lights without wires is a fine thing to do. I'm all for it. But what is the high energy deensity application that absolutely requires mobility? It seems to me that there is one in particular and that is robotics.
Moreover, this technology has a limitation of range that actually becomes a feature when applied to robotics. As we know all too well in the age of Iragi battle drones Asimov's laws of robotics are a fantasy relic of a time that couldn't imagine how software would really develop. The truth is, robots can be dangerous and this kind of technology effectively puts a leash on their range. They can do whatever within the home, but they can't just go out and go for a walk. It's a classic example of a limitation becoming a feauture.
So how would it solve the immigration issue?
I just mentioned this range limitation. So then, how could we use this for agricultural robots that would alleviate the need for low paid illegal immigrant farm labor? No problem. Obviously tractors bring their own power sources into the field. So, power in the field is not a problem. You would simply have gangs of robots attatched to resonant inductor power modules hanging off arms of the tractor. Say each tractor controls six platoons of robotic field hands with six resonant inductor orbs. They could work twenty four hours shifts. One tractor and labor gang could harvest dozens of farms per season in a timely manner.
If you need higher power, that's not a problem. There's no reason this technology is limited to 110volts. You can use 600V or 1200V. As much as you need. Your robotic workers would be as powerful as necessary.
Not only would it eliminate the need for foreign labor, it would also reduce the need to use high impact farming techniques such as posioning the soil with bromide gas and laying down plastic mulch. These things are done in the name of economy because it's too expensive to have human labor go through a farm and pick weeds. Monocrops are also planted for the same economic considerations. By dramatically shifting the labor equation you would enable a vast increase in the use of organic farming techniques.
The implications of this technology are far more revolutionary than re-charging an MP3 player.
While 40% isn't great for general use, I'd wager that it's several times more efficient, system-wide, than using non-rechargable batteries.
I wonder how well it takes to moving objects. Such a system could be a boon for moving us toward grid-powered electric vehicles if there were regular transmission coils embedded in heavily-trafficked roads, and they'd be a lot closer to the car than 7 feet, so they'd probably get much higher effiency numbers (perhaps even comparable to battery charge/discharge losses).
Nothing says 'welcome to the neighborhood' like a gunny sack full of dead squirrels.
The FCC has (had?) an exemption that allows RF testing on the site of a college / university.
If you tried this off-campus, you would be toast. The BBC article mentioned a 40% efficiency. For a 60 W light bulb, this implies about 150 W of total input power and 90 W of losses. Some of these losses must be RF losses. The device must be over the 1 W maximum transmitter power limit of the FCC for personal use, assuming the FCC would even permit the device.
The HF frequency range (10 MHz) is used extensively for communications. A number of amateur radio operators are likely to be unhappy if someone is using a device like this near their radio receivers.
Tesla would be shaking his head in disgust.
do a wiki lookup on the "earth battery"; after that, jump over to "Wardenclyffe".
People really need to stop thinking that hertzian waves are the only thing under the sun.
Why, yes, I AM a Pagan Libertarian.
Tesla worked under Edison for a short while. When he left, he insulted the "throw it at a wall and see what sticks" methodology to Edison's labs. Tesla stated that if Edison's team ever bothered with a little theory now and then instead of relentless experiments, he would have fewer cases of that 90% perspiration and 10% inspiration.
Well, yes. And no.
The general case is just going to be impossible. Magnetic fields are in some ways similar to light. You can use magnets to focus the field, and increase the efficiency of power transmission. But these magnets are similar to lenses. You'd want to use permanent magnets, otherwise you'll be wasting a lot of energy focusing the transmitted field -- more than you'd gain in efficiency. And changing the configuration of complex arrays of permanent magnets is time consuming at best. The best place to use one of these things would be the very place you'd want to run a wire anyway -- a fixed installation.
Transformers have come a long way in terms of efficiency, basically by "braiding" both coils together around a low "reluctance" core.
After all, I am strangely colored.
The weird thing is plants seem to flourish, almost coming back from the dead when they spend time in the general MRI area. We saw a regular turn over of flowers from people that were looking to revive their plants.
Anything that has that drastic of an outcome on simple life forms, definitely needs to be studied longer to ascertain it's effect on other life forms. Whether it's good, or bad.
Shane
I agree... there is nothing new here... especially in light of Nikola Tesla who powered lights remotely for miles in diameter around his generator. His dream was that both light and electricity would be free to everyone through the air.
I realize you are joking, but:
"Lightsaber technology was developed over thousands of years. The first lightsaber models, used thousands of years BBY, had to be connected to an external power source since a power source small enough to fit in a saber's hilt had not yet been discovered. Power sources often consisted of a power pack worn on the back and connected to the lightsaber's hilt by a power cord."
Taken from Wikipedia.
This may be a point when dorkiness crosses the line into pedantry.
Yupp, this is "well known" in antenna and microwave R&D circles. There are many theories, ranging from RF exposure to working odd hours... I have sired four girls vs. zero boys, and even though this is just one data point, the trend is very much obvious in departments I've worked.
BTW, the combination of WiTricity and Pendry looks like a marriage made in heaven -> Metamagical materials and cargo cult electromagnetics go together...
Yes, it is completely new. First, we can start with a simple test: could anyone do this before?
Answer: No.
A transformer is a relatively simple device, with two coils of wire. There are not a lot of restrictions for the device to work. You can choose different numbers of coils and sizes, if you wish to transform volts to current and vice versa, you can add cores and change the geometry to alter various other properties. And as other commenters have observed, you'd lose a few orders of magnitude over a distance of 2m with a coil of this size. These guys got 40% efficiency. Yes, it is new, because they made it work.
It's every bit a breakthrough as the telephone was to the telegraph. Sure, they're sending simple signals down a wire, to carry information. However, one has a high degree of cleverness and innovation modifying a basic concept, and that's what makes a revolutionary device.
Is it useful? That's another question.