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Nokia Developed Wireless Power-Harvesting Phones
Al writes "An engineer from Nokia's UK research labs says that the company is developing technology that can harvest ambient electromagnetic radiation to keep a cellphone going. The researcher says that his group is working towards a prototype that could harvest up to 50 milliwatts of power — enough to slowly recharge a phone that is switched off. He says current prototypes can harvest 3 to 5 milliwatts. It will require a wideband receiver capable of capturing signals from between 500 megahertz and 10 gigahertz — a range that encompasses many different radio communication signals. Other researchers have developed devices that can harvest more modest power from select frequencies. A team from Intel previously developed a compact sensor capable of drawing 6 microwatts from a 1.0-megawatt TV antenna 4.1 kilometers away."
Wake me up when it can harvest 1.21 gigawatts
Another great example as to how Tesla has shaped our future. Truly ahead of his time by leaps and bounds.
Crystal radio sets harvested enough power to drive an earphone-sized speaker.
In some circumstances, florescent light bulbs can draw enough power from a nearby power source to light up.
Knowledge is how to play a game, intelligence is how to win, wisdom is knowing what game to play.
"Harvesting" is cool and all, but what I've been wondering is why manufacturers haven't been putting solar panels in phones. Such as my Casio G-Shock watch I bought 3 years ago...it has solar panels built into the watch face and a rechargeable battery, and works fantastic. I was looking at the iPhone the other day and thinking they could probably do the same thing with the large surface area of the "face" of the phone. Seems like a logical, relatively easy addition if you ask me.
Most of that power would be absorbed by some material, nearby concrete, or ground.
Give a man a fish and you have fed him for today. Teach a man to fish, and he'll say "WHERE'S MY FISH, YOU IDIOT?"
They all work, they just don't cure the kind of cancer you have.
Sorry.
Shouldn't be too hard to harvest energy from changes of momentum and orientation, similar to how many mechanical watches have for years been able to wind themselves.
-- In the beginning was the WORD, and the WORD was UNSIGNED, and the main(){} was without form and void...
When I was in college in the early 80s we built inductive loops to draw power from the local radio station. We drew enough power to light an incandescent bulb. The only problem was the radio station had remote power meters across their broadcast footprint, and we dropped their power levels significantly for the station to call the college. The funny thing was the college knew exactly what professor to call for this was done repeatedly through the semesters, and the radio station could get a pretty good reading on where the actual drop was coming from per their power readings.
10 seconds on high should be plenty
Another great example as to how Tesla has shaped our future. Truly ahead of his time by leaps and bounds.
I know Tesla is a posterboy for the Slashdot community, but I think you mean http://en.wikipedia.org/wiki/Heinrich_Hertz. Hertz was responsible for the discovery that you could generate and detect radio waves.
That lead to the use of radio for communications, which is why such a modern device as the article describes. Tesla envisioned pumping energy into the air via dedicated stations. I don't think he envisioned a situation where we would be pumping so much energy into the air for communications, that there would be usable power as a byproduct.
I find it frightening, not "cool", that such a device is possible, given that my body relies on faint electrical signals.
Please help metamoderate.
"... if 1 Megawatt gives you 6 milliwatts..." That's off by a factor of 1,000. One megawatt gave 6 microwatts.
The Nokia press release says they are expecting almost 10,000 times 6 microwatts, all received inside a tiny cell phone that is covered with metal.
no more so than a bunch of radios tuning in. If an antenna or chunk of metal is between you and a signal, your signal quality will be degraded. If not, you have a virtual line of sight (or LOS via reflections from the ground, buildings, etc) and can receive like normal. Its like worrying about your lawn receiving less light because your neighbor has solar panels on his roof. If the panels were between you and your lawn, it wouldn't matter if they were generating power, or just made of plywood, your lawn would be in the shade, but since they're not, your grass will be just as green. Its not like these antennas suck up the power, it won't bend the radio waves towards it like a magnetic pole would affect magnetic fields.
Is it sad that I am more likely to recognize you and your posts by your sig than your name or UID?
Its not like these antennas suck up the power, it won't bend the radio waves towards it like a magnetic pole would affect magnetic fields.
Well, actually they do. It's not at all significant in the grand scheme of things, but antennas do affect (reduce) the signal in the area near them. Antenna designers refer to an antenna's "aperture", the effective area in space from which it can "suck" signal. This is a very abstracted view, but is a useful analogy to understand how antennas affect electromagnetic waves passing near them. It is as if your power-sucking cell phone device creates a radio shadow a couple feet in diameter, instead of only the size of the antenna. Fortunately, the effect only extends a few wavelengths from the antenna at most (the so-called near field region) and has absolutely no impact on receivers outside that space.
I am a geek attorney, but not your geek attorney unless you've already retained me. This is not legal advice.
Would that be cheaper to do than sticking a solar cell on the phone?
Excuse me, but please get off my Pennisetum Clandestinum, eh!
Can a device like the ones we are discussing actually "pull" more power from the source if present ?
Yes, the process uses inductive coupling and works just like a transformer. http://en.wikipedia.org/wiki/Inductive_coupling
There are two ways to transfer energy wirelessly. Either you couple the receiver to the transmitter using the near field (inductive coupling), or you obtain the energy from the radiated energy in the far field (electromagnetic radiation). http://en.wikipedia.org/wiki/Wireless_energy_transfer
This is an easy project for a 16 year old provided mummy or daddy is a full professor of physics at Stanford.
From scarped cliff or quarried stone she cries "A thousand types are gone, I care for nothing, no not one."