Wireless Power (I wish)

[sliston32]

maybe one day........

http://news.bbc.co.uk/1/hi/technology/6129460.stm

[440roadrunner]

First, your link is broken

http://news.bbc.co.uk/1/hi/technology/6129460.stm


EDIT Ok, I ackowledge that you fixed it


This kind of speculation, in my opinion, is "junk science" at it's most glorious level.

"Although the team has not built and tested a system,........."


That statement right there should be a huge red flag. A system "as described" including some sort of resonant radiators, should not be all that hard to rig for testing. Talk is cheap


Another quote from the article:


"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. ..........."


First, Tesla did not experiment with "long range" energy transfer, he may have theorised, dreamed, or speculated about same, but he could not get it to work, because it WON'T. He didn't fail because he ran out of money, he failed because IT DOES NOT WORK


The fact of the matter is, in order to get ANY electromagnetic field (strong enough) to transfer enough energy to be of significance, it would do at least two bad things. The first is that it would be a danger to humans, the very same sort of complaint that some people are afraid of concerning RF radiation from cell phones. I personally believe that real world, actual damage is a myth, but the fact is, that if cell phones WERE powerful enough transmitters, the RF radiation WOULD do damage to humans. I suppose that if you took an old model (high power) bag phone and strapped it to your "bag" while making a 24hr a day call for enough time, you would eventually suffer damage


I would suggest to you that ANY device of this nature that can actually transfer enough juice to run a simple laptop, say, from across the room, some 10 feet, would be so powerful as to absolutely guarantee damage to humans, if one was close enough to the transmitter. Imagine your small child reading at the desk where the transmitter is located, while you are across the room with your "full wireless" laptop.

Possibly a good example of energy transfer "not working" IS IN FACT ordinary AM broadcast stations. Even a 50KW "clear channel" station will not transfer any real amount of energy, say as close as 1/2 mile away. The attenuation of the field drops immensly fast. I'm no math expert, but the the law of inverse squares comes to mind

The second thing that ANY strong field such as this would do is to disrupt RADIO communications. This can include ANY wireless, radio, TV, pager, cellphone, ANY rf device, including fer heck sake, yer garage door opener or the rf remote for your dish controller

Next, basically what is shown as being the radiating device, is nothing more or less than a resonant loop antenna. Do some search on "small loops" or "small resonant loops." One thing you'll discover, is that even low power levels at HF can result in VERY hi copper (I squared R) losses, as well as extremely high voltages in parts of the loop.

As an amateur radio operator, short wave radio listener, and who has worked part of my life within the RF community, I can tell you that the modern day situation concerning the "RF noise floor" is not pretty. There is almost no urban situation that is any longer good for LF, MF, or HF communications. Now, the FCC is all excited, in the US, at least, about so called BPL--internet over power lines. If you don't think this disrupts HF communications, simply get in your long range travel device, go to one of the active BPL setups, and LISTEN with any HF radio

Anyone that's ever tried to listen to an ordinary broadcast radio near a welding shop knows about which I speak.


At the bottom of the page a small box "shows" how this works:


'Tails' of energy from antenna 'tunnel' up to 5m (16.4ft)


That statement has no basis in fact, and IN FACT discards some 100 years of radio theory. Transmitted, radiated radio signals do not "tunnel," unless perhaps you are using something like a dish, not useable at HF


Another quote:

"Energy not transferred to laptop re-absorbed by source antenna"


Too bad I'm not allowed to use the BS word on here. RF energy, once radiated from an antenna INTO SPACE, is not "re-absorbed" by some magic reflection from a nearby antenna, unless it is some directional array, and this condition IS NEVER good for the transmitter.

I don't know what planet this guy came from........


Any RF engineer will tell you that this idea is pure BS

[christopher_wolf]

Well....I would have made a lengthy argument including many points of articulation against that article, but I think RoadRunner summed it up quite nicely.

I did miss his presentation over in San Francisco the other day, but I would seriously like to see experimental data on that. The only thing resembling such "resonance" effects I have seen in a lab setting have been quite short range, they can call it "tunneling" if they want to make it look akin to a Tunneling Electron Microscope and the tunneling effect in quantum mechanics if they want, , but that is just calling it a different name. What they don't mention is the work involved to get even a prototype of such a coupling device to just marginal efficiency in practice. One can easily build a small radio that needs little power to pickup signals from local stations, but that is simply insufficient for the kind of power transfer that is required for consumer electronics, even in the near future with passable efficiency over long ranges. It is also not entirely feasible as the ranges they are talking about have to be very small to get anything across efficiently; thereby making it of no further use in a real world setting than induction chargers already are. I don't quite see their point in why it is that great of a "new" thing in the microscopic and nanoscale realms either as they have their fair share of such effects and already benefit from such effects.

The other thing that has me worried is, as stated previously, the flux of the energy through living tissue. Assuming that they can somehow construct a field applicable prototype that has the ability to wirelessly power a device within a large room, they have to deal with the fact that such energy is going to radiate (or resonate, they are unclear as they are seperate things) through the human operator's body. There is a reason that MRI systems have to be cleared and are capped at a certain level (around 11T to 12T), even though one can go higher and try to get much better imaging resolution (ignoring the standing wave effect). The main worry has to do with heating of the tissue and, in the case of high NIEMR, the poorly understood effects it has on the human body. Even if it only couples when it resonates with a particular object, nobody currently has any way of knowing or measuring all the possible couplings it could have with the human body.

Finally, they really shouldn't have gone to the press directly about this before publishing, at the least, a review paper complete with abstract and future experimentation details, submitting that to a research journal, and getting actual feedback from their research peers. As far as actual research practice goes, that isn't generally looked upon with great favor.

This falls under the class of the question "They are getting funded to do this?"