"Prototype Nokia phone recharges without wires"

I wonder what bands they're pulling that from. AM BCB, in the vicinity of

1490kHz around here, puts out that kind of power density, but that's not something you can recieve in a cell phone form factor.

Tim

-- Deep Friar: a very philosophical monk. Website:

"John Doe"

** Looks like an April Fool's joke to me.

No science, no testable facts and not from the horse' mouth - ie Nokia.

It a load of bunk.

.... Phil

On a sunny day (17 Jun 2009 04:44:39 GMT) it happened John Doe wrote in :

I did read about it some time ago, and UNLESS you live under a TV or radio tower it is total crap.

It is even worse then that MIT Tesla re-invention. Nokia may publish these things to draw attention, but in the long run it will work against them.

Already decided my next phone would be no Nokia after reading that.

5mW is probably an over estimate like most of these things.

Gathered 24/7 5mW is enough to make a cup of tea once every 217 days - utterly pointless.

10 times as much is still pointless and will not recover the energy used to manufacture the harvesting system.

Wait, what? No shit the cell phone takes more energy to manufacture, that's completely beside the point. What, did you think this was supposed to power your home?

Tim

--
Deep Friar: a very philosophical monk.
Website: http://webpages.charter.net/dawill/tmoranwms

After a few minutes Googling I found this:

"Exterior RF values ranged from nondetectable to 20.9 ?W/cm2 (mean ± SD = 2.6 ± 4.0 ?W/cm2)"

So taking this average of 2.6uW/cm^2, you would need an antenna with an effective area of about 20,000 cm^2 to get 50mW. I can't see that fitting in a phone. Maybe you would get a useful amount of power if you were right next to another phone which is actually making a call, but I can't see it giving a useful amount of power in most situations.

There is another article here which gives a bit more information:

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To reply to me directly:

Replace privacy.net with: totalise DOT co DOT uk and replace me with
gareth.harris

I wonder why they're aiming at freqs that are so high and not trying to soak up the ambient from the mains? That would seem to be a source with a lot higher power density, most of the time and for most users. What's on the scope when I grab a bare probe tip isn't in the GHz range.

--
Rich Webb     Norfolk, VA

I said the harvesting system will never recover the energy used to manufacture the harvesting system alone never mind the whole phone.

I think the technology is aimed at technically illiterate eco tossers who think buying a phone with an energy harvesting system is somehow saving the planet.

Selling into the market of technically illiterate eco tossers by dishonestly portraying the phone as 'green' is the only justification for development of the technology (for mobile phone use).

If the justification is supposed to be increased time between charges then why isn't there a market for phones with larger batteries? Why don't they use the cost and space of the harvesting system for more battery instead which has the advantage of increasing talk time also.

The only reasonable application for ambient energy harvesting is in ultra low power systems where battery replacement or charging is difficult and/or expensive.

Would it not be way more effective to put a tiny solar cell on a phone? It recovers RF of "slightly" higher frequency, probably produces more power as well.

M

So? They're not powering the factory with the things, they're powering the cell phones with the things. How can that be at all relevant?

Yup. I wouldn't mind having a cell phone I didn't have to hook on the charger every so often. They should investigate acceleration and thermoelectric methods too, like some of those "forever-wound" wristwatches.

Tim

--
Deep Friar: a very philosophical monk.
Website: http://webpages.charter.net/dawill/tmoranwms

"Tim Williams"

** Try learing to read - d*****ad. ** Shame you have no idea what the point being made is. ** Fuckwit, totally irrelevnt question.

..... Phil

"Tim Williams"

** Means than from an energy conservation perspective - it is bette the system was never made.

Dickhead.

** Massive straw man fallacy.

Wanker.

..... Phil

Good idea - coat one side of the phone with PV and provide a clip to a belt or pocket to keep it seeing light when carrying. Maybe a problem with muggers though.

--
Dirk

http://www.transcendence.me.uk/ - Transcendence UK
http://www.theconsensus.org/ - A UK political party
http://www.onetribe.me.uk/wordpress/?cat=5 - Our podcasts on weird stuff

You need to be taught some manners, troll

"Phil Allis> Path:

news.astraweb.com!border1.newsrouter.astraweb.com!feed.news.qwest.net!mpls-nntp-02.inet.qwest.net!feeder.erje.net!news.musoftware.de!wum.musoftware.de!fu-berlin.de!uni-berlin.de!individual.net!not-for-mail

Wavelength.

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You can\'t have a sense of humor, if you have no sense!

Put the PV on the top of the tinfoil hat you should be wearing to keep from getting brain cancer from that cell phone.

Put a propellor up there too so you can harness wind power.

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Paul Hovnanian     mailto:Paul@Hovnanian.com
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Have gnu, will travel.

Hang one on his belt so he can recycle those tacos into phone calls, too.

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You can\'t have a sense of humor, if you have no sense!

Samsung just announced a phone with a solar panel covering the whole of the back. They claim (optimistically no doubt) 5 to 10 minutes talk time per hour of solar charging.

It might actually be useful to those in the few places in the world with lots of sun, not much electricity and cell phone coverage. It will mostly be sold to tossers to be worn like a green arm band (while using their iphone).

Because this idea is simpler and will work Area of surface = 50 cm^2 Max sunlight intensity 0.1W/cm^2 Total incoming on surface = 5W Efficiency = 20%, energy harvested = 1W

Which is more than enough to keep the phone charged at a moderate call rate in sunny climes, even when insolation is a fraction of that assumed.

--
Dirk

http://www.transcendence.me.uk/ - Transcendence UK
http://www.theconsensus.org/ - A UK political party
http://www.onetribe.me.uk/wordpress/?cat=5 - Our podcasts on weird stuff