"Prototype Nokia phone recharges without wires"

[John Doe]

The idea is straightforward. Do you think the energy specification
"5 milliwatts" is correct? Is the prediction of "50 milliwatts"
reasonable? Mainly curious, Thanks.


http://tech.yahoo.com/blogs/null/143945

"...a cell phone that recharges itself using a unique system: It
harvests ambient radio waves from the air, and turns that energy
into usable power. Enough, at least, to keep a cell phone from
running out of juice... harvesting ambient electromagnetic energy is
never going to offer enough electricity to power your whole house or
office, but it just might be enough to keep a cell phone alive and
kicking. Currently Nokia is able to harvest all of 5 milliwatts from
the air; the goal is to increase that to 20 milliwatts in the short
term and 50 milliwatts down the line..."

 

[Tim Williams]

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

 

[Phil Allison]

"John Doe"

The idea is straightforward. Do you think the energy specification
"5 milliwatts" is correct? Is the prediction of "50 milliwatts"
reasonable? Mainly curious, Thanks.


http://tech.yahoo.com/blogs/null/143945

** 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

 

[nospam]

The idea is straightforward. Do you think the energy specification
"5 milliwatts" is correct? Is the prediction of "50 milliwatts"
reasonable? Mainly curious, Thanks.

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.

--

 

[Tim Williams]

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

 

[Rich Webb]

After a few minutes Googling I found this:

http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=1367839

"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:

http://www.technologyreview.com/communications/22764/

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.

 

[nospam]

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?

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.
--

 

[TheM]

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.

--

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

 

[Tim Williams]

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

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?

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

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

 

[Phil Allison]

"Tim Williams"

"nospam"

Wait, what? No shit the cell phone takes more energy to manufacture,

** Try learing to read - dickhead.

that's completely beside the point.

** Shame you have no idea what the point being made is.

What, did you think this was supposed to power your home?

** Fuckwit, totally irrelevnt question.


...... Phil

 

[Phil Allison]

"Tim Williams"

"nospam"

So?

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

Dickhead.

They're not powering the factory with the things,

** Massive straw man fallacy.

Wanker.


...... Phil

 

[Dirk Bruere at NeoPax]

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.

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

 

[John Doe]

You need to be taught some manners, troll

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From: "Phil Allison" <phil_a tpg.com.au>
Newsgroups: sci.electronics.design
Subject: Re: "Prototype Nokia phone recharges without wires"
Date: Thu, 18 Jun 2009 10:48:49 +1000
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"Tim Williams"

** Try learing to read - dickhead.



** Shame you have no idea what the point being made is.




** Fuckwit, totally irrelevnt question.


..... Phil

 

[Phil Allison]

"John Dope"

You need to be taught some manners, troll

** ROTFLMAO !!!!

YOU are the FUCKING TROLL - arsehole !!!

Wasting people's time with ASININE postings.

PISS OFF - you brainless, ignorant twat.




..... Phil

 

[nospam]

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.

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).

--

 

[Dirk Bruere at NeoPax]

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.

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

 

[TheM]

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.

Certainly way way ahead of 5mW, and simpler, too.

Idea of RF (non-light) harvesting for mobile phone is just plain idiotic.

M

 

[nospam]

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.

What's on the scope is pick up from a man sized antenna with respect to
ground. A phone doesn't have space for a man sized antenna or any ground to
work against.
--

 

[Rich Grise]

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).

Yeah - everybody knows they poke holes in the biosphere. ;-P

Cheers!
Rich

 

[Dirk Bruere at NeoPax]

Certainly way way ahead of 5mW, and simpler, too.

Idea of RF (non-light) harvesting for mobile phone is just plain idiotic.

And in the areas where it isn't, you don't want to hang around!

--
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