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  #1 (permalink)  
Old 11-15-2006, 06:35 AM
John Navas
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Default NEWS: Physics promises wireless power

<http://news.bbc.co.uk/2/hi/technology/6129460.stm>:

The tangle of cables and plugs needed to recharge today's electronic
gadgets could soon be a thing of the past.

US researchers have outlined a relatively simple system that could
deliver power to devices such as laptop computers or MP3 players
wirelessly.

The concept exploits century-old physics and could work over
distances of many metres, the researchers said.

Although the team had not built and tested a system, computer models
and mathematics suggest it would work.

"There are so many autonomous devices such as cell phones and
laptops that have emerged in the last few years," said Assistant
Professor Marin Soljacic from the Massachusetts Institute of
Technology and one of the researchers behind the work.

"We started thinking, 'it would be really convenient if you didn't
have to recharge these things'.

"And because we're physicists we asked, 'what kind of physical
phenomenon can we use to do this wireless energy transfer?'."

Energy trap

The answer the team came up with was "resonance", a phenomenon that
causes an object to vibrate when energy of a certain frequency is
applied.

"When you have two resonant objects of the same frequency they tend
to couple very strongly," Professor Soljacic told the BBC News
website.

Resonance can be seen in musical instruments for example.

"When you play a tune on one, then another instrument with the same
acoustic resonance will pick up that tune, it will visibly vibrate,"
he said.

Instead of using acoustic vibrations, the team's system exploits the
resonance of electromagnetic waves. Electromagnetic radiation
includes radio waves, infrared and x-rays.

Typically, systems that use electromagnetic radiation, such as radio
antennas, are not suitable for the efficient transfer of energy
because they scatter energy in all directions, wasting large amounts
of it into free space.

To overcome this problem, the team investigated a special class of
"non-radiative" objects with so-called "long-lived resonances".

When energy is applied to these objects it remains bound to them,
rather than escaping to space. "Tails" of energy, which can be many
metres long, flicker over the surface.

"If you bring another resonant object with the same frequency close
enough to these tails then it turns out that the energy can tunnel
from one object to another," said Professor Soljacic.

Hence, a simple copper antenna designed to have long-lived resonance
could transfer energy to a laptop with its own antenna resonating at
the same frequency. The computer would be truly wireless.

Any energy not diverted into a gadget or appliance is simply
reabsorbed.

The systems that the team have described would be able to transfer
energy over three to five metres.

[MORE]

--
Best regards, FAQ for Wireless Internet: <http://Wireless.wikia.com>
John Navas FAQ for Wi-Fi: <http://wireless.wikia.com/wiki/Wi-Fi>
Wi-Fi How To: <http://wireless.wikia.com/wiki/Wi-Fi_HowTo>
Fixes to Wi-Fi Problems: <http://wireless.wikia.com/wiki/Wi-Fi_Fixes>

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  #2 (permalink)  
Old 11-15-2006, 01:43 PM
Axel Hammerschmidt
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Default Re: NEWS: Physics promises wireless power

John Navas <spamfilter0@navasgroup.com> wrote:

> <http://news.bbc.co.uk/2/hi/technology/6129460.stm>:
>
> The tangle of cables and plugs needed to recharge today's electronic
> gadgets could soon be a thing of the past.
>
> US researchers have outlined a relatively simple system that could
> deliver power to devices such as laptop computers or MP3 players
> wirelessly.
>
> The concept exploits century-old physics and could work over
> distances of many metres, the researchers said.


<snip>

> [MORE]


http://en.wikipedia.org/wiki/Nikola_Tesla

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  #3 (permalink)  
Old 11-15-2006, 05:17 PM
Thurman
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Posts: n/a
Default Re: Physics promises wireless power


"John Navas" <spamfilter0@navasgroup.com> wrote in message
news:l0dll2l6h3ol9oapnfbk4s1qccvifms4lv@4ax.com...
> <http://news.bbc.co.uk/2/hi/technology/6129460.stm>:
>

<snip>
> "And because we're physicists we asked, 'what kind of physical
> phenomenon can we use to do this wireless energy transfer?'."
>
> Energy trap
>
> The answer the team came up with was "resonance", a phenomenon that
> causes an object to vibrate when energy of a certain frequency is
> applied.
>
> "When you have two resonant objects of the same frequency they tend
> to couple very strongly," Professor Soljacic told the BBC News
> website.


Reminds me of the rumored weapon "Hammer of Thor" to be used in warfare this
decade.

From a high flying altitude, a directed particle beam could be focused
tightly enough to reduce a human to a puddle of fat and grease >while inside
a car< in a few seconds.

We could combine cell phones and directed energy to eliminate California
high speed auto chases. ;-)



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  #4 (permalink)  
Old 11-15-2006, 06:14 PM
Jeff Liebermann
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Default Re: NEWS: Physics promises wireless power

John Navas <spamfilter0@navasgroup.com> hath wroth:

><http://news.bbc.co.uk/2/hi/technology/6129460.stm>:
>
> US researchers have outlined a relatively simple system that could
> deliver power to devices such as laptop computers or MP3 players
> wirelessly.
>
> The concept exploits century-old physics and could work over
> distances of many metres, the researchers said.

(...)

Yawn. Basically, they're building a resonant RF transformer. Coupling
efficiency is maximum at resonance so that makes sense. However it's
still radio waves and physics limits what can be done at their chosen
frequency of 6.4MHz. There's no "wave magnet" available in radio
waves. We're working in the near field where field strength varies
roughly linearly with the distance. Double the distance and lose half
the power. At the claimed 5 meters range, there's very little RF
available to charge the device. My guess is about 5% efficiency
depending on coil size. I guess energy conservation is of little
concern because to deliver typical charger power, a substantial amount
of RF must be radiated and lost to nowhere in particular. The device
also has to have a relatively high Q coupling coil in order to work.
That's difficult to do in a small package and will be seriously
detuned by body capacitance. Want more delivered power? Get a bigger
coil. Want gross inefficiency? Use a small coil.

The inability to direct the RF will also causes problems. Much of the
6.4MHz signal will get into the cell phone or radio, mix well, and get
served as intermod, rectification, and other unwanted circuit
malfunctions. Shielding will probably be necessary.

What does make this potentially practical is that the power
consumption of portable devices are dropping rapidly. Chances are
slim that they can meet FCC Part 15 radiation requirements and still
deliver useable amounts of RF, but that can be negotiated (or ignored
as in BPL).

While useless for delivering substantial amounts of power, resonant
transformer coupling might be suitable for small loads, and only if
one doesn't care about efficiency.

Incidentally, the 6.4MHz area is straddled by marine SSB and GMDSS
users. I'm sure they'll be thrilled with the new source of RF
pollution.

Ok, bring on the investors.

--
Jeff Liebermann jeffl@comix.santa-cruz.ca.us
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

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  #5 (permalink)  
Old 11-15-2006, 06:23 PM
Thomas T. Veldhouse
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Posts: n/a
Default Re: NEWS: Physics promises wireless power

In alt.cellular.cingular John Navas <spamfilter0@navasgroup.com> wrote:
> <http://news.bbc.co.uk/2/hi/technology/6129460.stm>:
>


I remember seeing this done with florescent light bulbs. It was an inspiring
demonstration for elementary school students in the 70s.

There are issues of concern. In the United States, electricity is transferred
in the power grid at 60Hz. 60Hz also corresponds to the frequency of the
Lithium Ion (Li+). It has been shown that lithium ions will leave the skin of
a human being when exposed to this frequency for an extensive period of time.
Some have hypothesized that this may cause depression issues in some people,
and others have suggested it may cause cancer. I recall this issue years ago,
but it has been largely squashed; however, I was able to find this one
resource:

http://oaspub.epa.gov/eims/eimscomm....load_id=437194

Now, my question is whether this same effect might exist when using a Tesla
coil (that is how this is accomplished). I don't see why it wouldn't. I
suspect that to alleviate concerns, they will have to find a frequency that
they "determine" is safe and tool standardization along that path.
Personally, I think that it is a bad idea from a health perspective and
shouldn't be done without many decades of testing on animals. I would hate to
be that pig.

--
Thomas T. Veldhouse
Key Fingerprint: D281 77A5 63EE 82C5 5E68 00E4 7868 0ADC 4EFB 39F0



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  #6 (permalink)  
Old 11-15-2006, 06:28 PM
John Navas
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Posts: n/a
Default Re: NEWS: Physics promises wireless power

On Wed, 15 Nov 2006 18:23:03 GMT, "Thomas T. Veldhouse"
<veldy71@yahoo.com> wrote in
<bWI6h.2721$Yy1.439@textfe.usenetserver.com>:

>In alt.cellular.cingular John Navas <spamfilter0@navasgroup.com> wrote:
>> <http://news.bbc.co.uk/2/hi/technology/6129460.stm>:

>
>I remember seeing this done with florescent light bulbs. It was an inspiring
>demonstration for elementary school students in the 70s.
>
>There are issues of concern. In the United States, electricity is transferred
>in the power grid at 60Hz. 60Hz also corresponds to the frequency of the
>Lithium Ion (Li+). It has been shown that lithium ions will leave the skin of
>a human being when exposed to this frequency for an extensive period of time.
>Some have hypothesized that this may cause depression issues in some people,
>and others have suggested it may cause cancer. I recall this issue years ago,
>but it has been largely squashed; however, I was able to find this one
>resource:
>
>http://oaspub.epa.gov/eims/eimscomm....load_id=437194
>
>Now, my question is whether this same effect might exist when using a Tesla
>coil (that is how this is accomplished). I don't see why it wouldn't. I
>suspect that to alleviate concerns, they will have to find a frequency that
>they "determine" is safe and tool standardization along that path.
>Personally, I think that it is a bad idea from a health perspective and
>shouldn't be done without many decades of testing on animals. I would hate to
>be that pig.


While your concern is understandable, I think it's overdone -- the
physics make such side effects unlikely.

--
Best regards, FAQ FOR CINGULAR WIRELESS:
John Navas <http://en.wikibooks.org/wiki/Cingular_Wireless_FAQ>

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  #7 (permalink)  
Old 11-15-2006, 06:34 PM
John Navas
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Posts: n/a
Default Re: NEWS: Physics promises wireless power

On Wed, 15 Nov 2006 10:14:22 -0800, Jeff Liebermann
<jeffl@comix.santa-cruz.ca.us> wrote in
<uqjml2pprbqj4p2ns370592jceeted45dc@4ax.com>:

>John Navas <spamfilter0@navasgroup.com> hath wroth:
>
>><http://news.bbc.co.uk/2/hi/technology/6129460.stm>:
>>
>> US researchers have outlined a relatively simple system that could
>> deliver power to devices such as laptop computers or MP3 players
>> wirelessly.
>>
>> The concept exploits century-old physics and could work over
>> distances of many metres, the researchers said.

>(...)
>
>Yawn. Basically, they're building a resonant RF transformer. [SNIP]


I respectfully suggest you actually read the research instead of making
assumptions and leaping from them to all those conclusions.

--
Best regards, FAQ FOR CINGULAR WIRELESS:
John Navas <http://en.wikibooks.org/wiki/Cingular_Wireless_FAQ>

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  #8 (permalink)  
Old 11-15-2006, 07:10 PM
SMS
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Posts: n/a
Default Re: NEWS: Physics promises wireless power

Jeff Liebermann wrote:

> What does make this potentially practical is that the power
> consumption of portable devices are dropping rapidly.


At the lower power levels, solar becomes practical as well, it's already
used on a lot of calculators. I had a bicycle computer that worked on
solar, and an old Sony Walkman (cassette) that used solar to charge an
internal NiCad.

Powering a laptop computer would be a real accomplishment, I wouldn't
hold my breath waiting for that to happen.

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  #9 (permalink)  
Old 11-15-2006, 07:13 PM
Jeff Liebermann
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Posts: n/a
Default Re: NEWS: Physics promises wireless power

John Navas <spamfilter0@navasgroup.com> hath wroth:

>On Wed, 15 Nov 2006 10:14:22 -0800, Jeff Liebermann
><jeffl@comix.santa-cruz.ca.us> wrote in
><uqjml2pprbqj4p2ns370592jceeted45dc@4ax.com>:
>
>>John Navas <spamfilter0@navasgroup.com> hath wroth:
>>
>>><http://news.bbc.co.uk/2/hi/technology/6129460.stm>:
>>>
>>> US researchers have outlined a relatively simple system that could
>>> deliver power to devices such as laptop computers or MP3 players
>>> wirelessly.
>>>
>>> The concept exploits century-old physics and could work over
>>> distances of many metres, the researchers said.

>>(...)
>>
>>Yawn. Basically, they're building a resonant RF transformer. [SNIP]

>
>I respectfully suggest you actually read the research instead of making
>assumptions and leaping from them to all those conclusions.


What research? There's no link. I did read the BBC article and found
it entertaining as I do enjoy reading science fiction. I also
indicated that it might be useful if the device being charged consumed
very little power. I do the math for resonant coupling for you if you
want. Give me a frequency, distance, and delivered power requirement
and I'll calculate the size of the coils, coupling efficiency, and
approximate radiation. No research required as it's in any
electronics textbook that covers RF xformers.

What is unique is this section:
To overcome this problem, the team investigated a special class
of "non-radiative" objects with so-called "long-lived resonances".

When energy is applied to these objects it remains bound to them,
rather than escaping to space. "Tails" of energy, which can be many
metres long, flicker over the surface.

"If you bring another resonant object with the same frequency close
enough to these tails then it turns out that the energy can tunnel
from one object to another," said Professor Soljacic.

I've never heard of this phenomenon and would be genuinely interested
in reading the research report. Last time I checked, there's no such
thing as a static or potential RF field but I'm open to new ideas. It
might be done with superconductors, where the field isn't dampened,
but not on a piece of wire.



--
Jeff Liebermann jeffl@comix.santa-cruz.ca.us
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

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  #10 (permalink)  
Old 11-15-2006, 07:22 PM
Jeff Liebermann
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Posts: n/a
Default Re: NEWS: Physics promises wireless power

SMS <scharf.steven@geemail.com> hath wroth:

>Powering a laptop computer would be a real accomplishment, I wouldn't
>hold my breath waiting for that to happen.


Minor trivia: Ever wonder how much power your laptop sucks? No need
to measure it. Just look at the rating on the battery charger.
Multiply volts times amps to get watts. The idea is that the battery
charger is suppose to run the laptop with the battery removed. It can
only do that if it has sufficient power capacity. Most of mine are
around 40 watts. However, I've seen Toshiba desktop replacements with
120 watt power adapter and blow enough hot air to suspect all of it is
being used.

--
Jeff Liebermann jeffl@comix.santa-cruz.ca.us
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

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  #11 (permalink)  
Old 11-15-2006, 07:57 PM
John Navas
Guest
 
Posts: n/a
Default Re: NEWS: Physics promises wireless power

On Wed, 15 Nov 2006 11:13:52 -0800, Jeff Liebermann
<jeffl@comix.santa-cruz.ca.us> wrote in
<m9pml21r0q9dndhdo2djulsneuceprt5uk@4ax.com>:

>John Navas <spamfilter0@navasgroup.com> hath wroth:
>
>>On Wed, 15 Nov 2006 10:14:22 -0800, Jeff Liebermann
>><jeffl@comix.santa-cruz.ca.us> wrote in
>><uqjml2pprbqj4p2ns370592jceeted45dc@4ax.com>:
>>
>>>John Navas <spamfilter0@navasgroup.com> hath wroth:
>>>
>>>><http://news.bbc.co.uk/2/hi/technology/6129460.stm>:
>>>>
>>>> US researchers have outlined a relatively simple system that could
>>>> deliver power to devices such as laptop computers or MP3 players
>>>> wirelessly.
>>>>
>>>> The concept exploits century-old physics and could work over
>>>> distances of many metres, the researchers said.
>>>(...)
>>>
>>>Yawn. Basically, they're building a resonant RF transformer. [SNIP]

>>
>>I respectfully suggest you actually read the research instead of making
>>assumptions and leaping from them to all those conclusions.

>
>What research? There's no link.


Google and all the other search engines down?
Took me all of about 30 seconds to find:

* "Wireless Non-Radiative Energy Transfer", Marin Soljacic, Aristeidis
Karalis, and J.D.Joannopoulos. 2006 AIP Industrial Physics Forum in
San Francisco (CA), USA, 2006. [Key words there are "non-radiative"]

* <http://eprintweb.org/S/article/physics/0611063>
physics/0611063 (November 2006)
Wireless Non-Radiative Energy Transfer
Aristeidis Karalis, J. D. Joannopoulos and Marin Soljacic
Received. 07 November 2006 Last updated. 07 November 2006
Abstract. We investigate whether, and to what extent, the physical
phenomenon of long-lifetime resonant electromagnetic states with
localized slowly-evanescent field patterns can be used to transfer
energy efficiently, even in the presence of extraneous environmental
objects. Via detailed theoretical and numerical analyses of typical
real-world model-situations and realistic material parameters, we
establish that such a non-radiative scheme could indeed be practical
for medium-range wireless energy transfer.
Subject. Optics; Classical Physics
Comment. 17 pages, 6 figures
Article Options
Full Text [link]

>I did read the BBC article and found
>it entertaining as I do enjoy reading science fiction.


You're accusing MIT, these scientists, and a professional society of
promulgating fiction, without having read the paper, based simply on
your own quick assessment of a BBC article?

>I also
>indicated that it might be useful if the device being charged consumed
>very little power. I do the math for resonant coupling for you if you
>want. Give me a frequency, distance, and delivered power requirement
>and I'll calculate the size of the coils, coupling efficiency, and
>approximate radiation. No research required as it's in any
>electronics textbook that covers RF xformers.
>
>What is unique is this section:
> To overcome this problem, the team investigated a special class
> of "non-radiative" objects with so-called "long-lived resonances".
>
> When energy is applied to these objects it remains bound to them,
> rather than escaping to space. "Tails" of energy, which can be many
> metres long, flicker over the surface.
>
> "If you bring another resonant object with the same frequency close
> enough to these tails then it turns out that the energy can tunnel
> from one object to another," said Professor Soljacic.
>
>I've never heard of this phenomenon and would be genuinely interested
>in reading the research report. Last time I checked, there's no such
>thing as a static or potential RF field but I'm open to new ideas. It
>might be done with superconductors, where the field isn't dampened,
>but not on a piece of wire.


Again, I respectfully suggest you actually read the research instead of
making assumptions and leaping from them to all those conclusions. I've
hopefully now got you started.

--
Best regards, FAQ FOR CINGULAR WIRELESS:
John Navas <http://en.wikibooks.org/wiki/Cingular_Wireless_FAQ>

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  #12 (permalink)  
Old 11-15-2006, 07:59 PM
SMS
Guest
 
Posts: n/a
Default Re: NEWS: Physics promises wireless power

Jeff Liebermann wrote:

> Minor trivia: Ever wonder how much power your laptop sucks? No need
> to measure it. Just look at the rating on the battery charger.
> Multiply volts times amps to get watts. The idea is that the battery
> charger is suppose to run the laptop with the battery removed. It can
> only do that if it has sufficient power capacity. Most of mine are
> around 40 watts. However, I've seen Toshiba desktop replacements with
> 120 watt power adapter and blow enough hot air to suspect all of it is
> being used.


The charger needs to be able to both charge the battery, and run the laptop

The only way to determine the power is to measure it.

I've instrumented a lot of laptops to measure all the different power
levels of each supply. In reality, the core, the hard drive, and the
screen consume magnitudes more power that all the other components.

You also really don't know the maximum power the laptop consumes until
you run a power virus program. You have to run these when you're doing
worst case design of the laptops thermal solution and power supply
components.


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  #13 (permalink)  
Old 11-15-2006, 08:01 PM
John Navas
Guest
 
Posts: n/a
Default Re: NEWS: Physics promises wireless power

On Wed, 15 Nov 2006 11:10:41 -0800, SMS <scharf.steven@geemail.com>
wrote in <455b6633$0$88669$742ec2ed@news.sonic.net>:

>Jeff Liebermann wrote:
>
>> What does make this potentially practical is that the power
>> consumption of portable devices are dropping rapidly.

>
>At the lower power levels, solar becomes practical as well, it's already
>used on a lot of calculators. I had a bicycle computer that worked on
>solar,


These are more entertainment than practicality, since they are very low
power, and still depend on batteries.

>and an old Sony Walkman (cassette) that used solar to charge an
>internal NiCad.


With hours of exposure needed for mere minutes of operation; i.e., not
practical.

>Powering a laptop computer would be a real accomplishment, I wouldn't
>hold my breath waiting for that to happen.


No kidding, because solar power density is way too low to be practical
ever outdoors, and isn't available indoors.

Do your homework before ranting.

--
Best regards, FAQ FOR CINGULAR WIRELESS:
John Navas <http://en.wikibooks.org/wiki/Cingular_Wireless_FAQ>

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  #14 (permalink)  
Old 11-15-2006, 08:02 PM
SMS
Guest
 
Posts: n/a
Default Re: NEWS: Physics promises wireless power

Thomas T. Veldhouse wrote:
> In alt.cellular.cingular John Navas <spamfilter0@navasgroup.com> wrote:
>> <http://news.bbc.co.uk/2/hi/technology/6129460.stm>:
>>

>
> I remember seeing this done with florescent light bulbs. It was an inspiring
> demonstration for elementary school students in the 70s.
>
> There are issues of concern. In the United States, electricity is transferred
> in the power grid at 60Hz.


The local grid is 60 Hz, but the long distance power transmission is
high voltage DC.

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  #15 (permalink)  
Old 11-15-2006, 08:09 PM
John Navas
Guest
 
Posts: n/a
Default Re: NEWS: Physics promises wireless power

On Wed, 15 Nov 2006 11:22:35 -0800, Jeff Liebermann
<jeffl@comix.santa-cruz.ca.us> wrote in
<23qml2hlpjmsu87ka4k05gindgiofqdbgs@4ax.com>:

>SMS <scharf.steven@geemail.com> hath wroth:
>
>>Powering a laptop computer would be a real accomplishment, I wouldn't
>>hold my breath waiting for that to happen.

>
>Minor trivia: Ever wonder how much power your laptop sucks? No need
>to measure it. Just look at the rating on the battery charger.
>Multiply volts times amps to get watts. The idea is that the battery
>charger is suppose to run the laptop with the battery removed. It can
>only do that if it has sufficient power capacity. Most of mine are
>around 40 watts. However, I've seen Toshiba desktop replacements with
>120 watt power adapter and blow enough hot air to suspect all of it is
>being used.


A solar panel in the contiguous United States on average delivers 19 to
56 W/mē or 0.45-1.35 kWh/mē/day. [National Renewable Energy Laboratory]

In other words, it would take a 4 sq meter solar panel to power my
ThinkPad reliably. That's a 6-1/2 foot square panel. Maybe Steven has
a hat that big, but I don't.

--
Best regards, FAQ FOR CINGULAR WIRELESS:
John Navas <http://en.wikibooks.org/wiki/Cingular_Wireless_FAQ>

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  #16 (permalink)  
Old 11-15-2006, 08:20 PM
John Navas
Guest
 
Posts: n/a
Default Re: NEWS: Physics promises wireless power

On Wed, 15 Nov 2006 12:02:08 -0800, SMS <scharf.steven@geemail.com>
wrote in <455b7242$0$88706$742ec2ed@news.sonic.net>:

>Thomas T. Veldhouse wrote:
>> In alt.cellular.cingular John Navas <spamfilter0@navasgroup.com> wrote:
>>> <http://news.bbc.co.uk/2/hi/technology/6129460.stm>:
>>>

>>
>> I remember seeing this done with florescent light bulbs. It was an inspiring
>> demonstration for elementary school students in the 70s.
>>
>> There are issues of concern. In the United States, electricity is transferred
>> in the power grid at 60Hz.

>
>The local grid is 60 Hz, but the long distance power transmission is
>high voltage DC.


In fact most current long distance power transmission is high voltage
AC, although HVDC is slowly gaining traction. Because of the high cost
of conversion between AC and DC, the breakeven for HVDC is about 600-800
km.

--
Best regards, FAQ FOR CINGULAR WIRELESS:
John Navas <http://en.wikibooks.org/wiki/Cingular_Wireless_FAQ>

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  #17 (permalink)  
Old 11-16-2006, 12:05 AM
Todd Allcock
Guest
 
Posts: n/a
Default Re: NEWS: Physics promises wireless power

At 15 Nov 2006 20:01:40 +0000 John Navas wrote:

> >Powering a laptop computer would be a real accomplishment, I wouldn't
> >hold my breath waiting for that to happen.

>
> No kidding, because solar power density is way too low to be practical
> ever outdoors, and isn't available indoors.
>
> Do your homework before ranting.
>


This negativity coming from someone who thinks they'll be beaming power
wirelessly to that same laptop soon?

They'll probably be beaming your laptop from one place to another a la
Star Trek before they'll ever be beaming power to it OTA! ;-)


--
Posted via a free Usenet account from http://www.teranews.com


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  #18 (permalink)  
Old 11-16-2006, 12:41 AM
John Navas
Guest
 
Posts: n/a
Default Re: NEWS: Physics promises wireless power

On Wed, 15 Nov 2006 17:05:41 -0700, Todd Allcock
<ElecConnec@AmericaOnLine.com> wrote in
<455ba235$0$21144$88260bb3@free.teranews.com>:

>At 15 Nov 2006 20:01:40 +0000 John Navas wrote:
>
>> >Powering a laptop computer would be a real accomplishment, I wouldn't
>> >hold my breath waiting for that to happen.

>>
>> No kidding, because solar power density is way too low to be practical
>> ever outdoors, and isn't available indoors.
>>
>> Do your homework before ranting.

>
>This negativity coming from someone who thinks they'll be beaming power
>wirelessly to that same laptop soon?
>
>They'll probably be beaming your laptop from one place to another a la
>Star Trek before they'll ever be beaming power to it OTA! ;-)


I'm guessing we'll first see wireless recharging of low power devices
like cell phones, cordless phones, digital cameras, wireless remotes,
MP3 players, etc. Cell phones in particular would benefit from this
technology, seamlessly charging whenever brought within range of a base
station.

--
Best regards, FAQ FOR CINGULAR WIRELESS:
John Navas <http://en.wikibooks.org/wiki/Cingular_Wireless_FAQ>

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  #19 (permalink)  
Old 11-16-2006, 03:50 AM
Jeff Liebermann
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Posts: n/a
Default Re: NEWS: Physics promises wireless power

SMS <scharf.steven@geemail.com> hath wroth:

>Jeff Liebermann wrote:
>
>> Minor trivia: Ever wonder how much power your laptop sucks? No need
>> to measure it. Just look at the rating on the battery charger.
>> Multiply volts times amps to get watts. The idea is that the battery
>> charger is suppose to run the laptop with the battery removed. It can
>> only do that if it has sufficient power capacity. Most of mine are
>> around 40 watts. However, I've seen Toshiba desktop replacements with
>> 120 watt power adapter and blow enough hot air to suspect all of it is
>> being used.

>
>The charger needs to be able to both charge the battery, and run the laptop


Agreed. I forgot about the battery. However, it charges at perhaps
C/10 or C/20 which would not contribute a huge increase to the drain
on the power supply. Still, you're correct and it should be added
into the guestimation.

>The only way to determine the power is to measure it.


Sure, but my point was that one could obtain a fair estimate of how
much the laptop will burn from the charger ratings. At the least, it
will not be more than the charger ratings or it will go into foldback,
shutdown, or burn out. The idea was to use the nameplate numbers to
estimate how much power would need to be delivered by a solar,
inductive, cazapitive, or wireless power solution.

>I've instrumented a lot of laptops to measure all the different power
>levels of each supply. In reality, the core, the hard drive, and the
>screen consume magnitudes more power that all the other components.
>
>You also really don't know the maximum power the laptop consumes until
>you run a power virus program. You have to run these when you're doing
>worst case design of the laptops thermal solution and power supply
>components.


Agreed (again). However, I'm just suggesting using the rating for an
initial estimate on laptop power consumption. In your experience, how
close is the power rating to the actual measured maximum power drain?
--
Jeff Liebermann jeffl@comix.santa-cruz.ca.us
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

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  #20 (permalink)  
Old 11-16-2006, 05:21 AM
SMS
Guest
 
Posts: n/a
Default Re: NEWS: Physics promises wireless power

Jeff Liebermann wrote:
> SMS <scharf.steven@geemail.com> hath wroth:
>
>> Jeff Liebermann wrote:
>>
>>> Minor trivia: Ever wonder how much power your laptop sucks? No need
>>> to measure it. Just look at the rating on the battery charger.
>>> Multiply volts times amps to get watts. The idea is that the battery
>>> charger is suppose to run the laptop with the battery removed. It can
>>> only do that if it has sufficient power capacity. Most of mine are
>>> around 40 watts. However, I've seen Toshiba desktop replacements with
>>> 120 watt power adapter and blow enough hot air to suspect all of it is
>>> being used.

>> The charger needs to be able to both charge the battery, and run the laptop

>
> Agreed. I forgot about the battery. However, it charges at perhaps
> C/10 or C/20 which would not contribute a huge increase to the drain
> on the power supply. Still, you're correct and it should be added
> into the guestimation.


Li-Ion batteries are charged at a rate between 0.2C and 0.7C, and
sometimes are fast as C.

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  #21 (permalink)  
Old 11-16-2006, 06:04 AM
Jeff Liebermann
Guest
 
Posts: n/a
Default Re: NEWS: Physics promises wireless power

SMS <scharf.steven@geemail.com> hath wroth:

>Jeff Liebermann wrote:
>> SMS <scharf.steven@geemail.com> hath wroth:
>>
>>> Jeff Liebermann wrote:
>>>
>>>> Minor trivia: Ever wonder how much power your laptop sucks? No need
>>>> to measure it. Just look at the rating on the battery charger.
>>>> Multiply volts times amps to get watts. The idea is that the battery
>>>> charger is suppose to run the laptop with the battery removed. It can
>>>> only do that if it has sufficient power capacity. Most of mine are
>>>> around 40 watts. However, I've seen Toshiba desktop replacements with
>>>> 120 watt power adapter and blow enough hot air to suspect all of it is
>>>> being used.
>>> The charger needs to be able to both charge the battery, and run the laptop

>>
>> Agreed. I forgot about the battery. However, it charges at perhaps
>> C/10 or C/20 which would not contribute a huge increase to the drain
>> on the power supply. Still, you're correct and it should be added
>> into the guestimation.


>Li-Ion batteries are charged at a rate between 0.2C and 0.7C, and
>sometimes are fast as C.


Ouch. At that high a charge rate, the charger would need to deliver
at least double the laptop current drain. So much for my theory.
Never mind.

--
Jeff Liebermann jeffl@comix.santa-cruz.ca.us
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

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  #22 (permalink)  
Old 11-16-2006, 02:51 PM
SMS
Guest
 
Posts: n/a
Default Re: NEWS: Physics promises wireless power

Jeff Liebermann wrote:
> SMS <scharf.steven@geemail.com> hath wroth:
>
>> Jeff Liebermann wrote:
>>> SMS <scharf.steven@geemail.com> hath wroth:
>>>
>>>> Jeff Liebermann wrote:
>>>>
>>>>> Minor trivia: Ever wonder how much power your laptop sucks? No need
>>>>> to measure it. Just look at the rating on the battery charger.
>>>>> Multiply volts times amps to get watts. The idea is that the battery
>>>>> charger is suppose to run the laptop with the battery removed. It can
>>>>> only do that if it has sufficient power capacity. Most of mine are
>>>>> around 40 watts. However, I've seen Toshiba desktop replacements with
>>>>> 120 watt power adapter and blow enough hot air to suspect all of it is
>>>>> being used.
>>>> The charger needs to be able to both charge the battery, and run the laptop
>>> Agreed. I forgot about the battery. However, it charges at perhaps
>>> C/10 or C/20 which would not contribute a huge increase to the drain
>>> on the power supply. Still, you're correct and it should be added
>>> into the guestimation.

>
>> Li-Ion batteries are charged at a rate between 0.2C and 0.7C, and
>> sometimes are fast as C.

>
> Ouch. At that high a charge rate, the charger would need to deliver
> at least double the laptop current drain. So much for my theory.
> Never mind.
>


Toshiba has Li-Ion batteries coming that can be fully charged in 10
minutes. The company claims that they will be out in 2008.

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  #23 (permalink)  
Old 11-16-2006, 02:54 PM
John Navas
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Posts: n/a
Default Re: NEWS: Physics promises wireless power

On Thu, 16 Nov 2006 06:51:52 -0800, SMS <scharf.steven@geemail.com>
wrote in <455c7b04$0$88640$742ec2ed@news.sonic.net>:

>Toshiba has Li-Ion batteries coming that can be fully charged in 10
>minutes. The company claims that they will be out in 2008.


[yawn] We've had 15 minute NiMH recharging for quite some time.

--
Best regards, FAQ FOR CINGULAR WIRELESS:
John Navas <http://en.wikibooks.org/wiki/Cingular_Wireless_FAQ>

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  #24 (permalink)  
Old 11-16-2006, 04:41 PM
Thomas T. Veldhouse
Guest
 
Posts: n/a
Default Re: NEWS: Physics promises wireless power

In alt.cellular.cingular John Navas <spamfilter0@navasgroup.com> wrote:
>
> While your concern is understandable, I think it's overdone -- the
> physics make such side effects unlikely.
>


They ALWAYS find out that they didn't account for something after millions of
people have been exposed. Considering the amount of energy in question here
is significant when considering long term exposure, I don't think it can be so
easily dismissed. Consider the fact that animal life has never in history
been so exposed to radiation as the modern human has. Adding more energy to
the mix is potentially more destructive so the frequency must be chosen wisely
and tested carefully.

--
Thomas T. Veldhouse
Key Fingerprint: D281 77A5 63EE 82C5 5E68 00E4 7868 0ADC 4EFB 39F0



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  #25 (permalink)  
Old 11-16-2006, 04:41 PM
Thomas T. Veldhouse
Guest
 
Posts: n/a
Default Re: NEWS: Physics promises wireless power

In alt.cellular.cingular SMS <scharf.steven@geemail.com> wrote:
> Thomas T. Veldhouse wrote:
>> In alt.cellular.cingular John Navas <spamfilter0@navasgroup.com> wrote:
>>> <http://news.bbc.co.uk/2/hi/technology/6129460.stm>:
>>>

>>
>> I remember seeing this done with florescent light bulbs. It was an inspiring
>> demonstration for elementary school students in the 70s.
>>
>> There are issues of concern. In the United States, electricity is transferred
>> in the power grid at 60Hz.

>
> The local grid is 60 Hz, but the long distance power transmission is
> high voltage DC.


We had this discussion before. Some of it is.

--
Thomas T. Veldhouse
Key Fingerprint: D281 77A5 63EE 82C5 5E68 00E4 7868 0ADC 4EFB 39F0



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  #26 (permalink)  
Old 11-16-2006, 04:45 PM
Thomas T. Veldhouse
Guest
 
Posts: n/a
Default Re: NEWS: Physics promises wireless power

In alt.cellular.cingular Jeff Liebermann <jeffl@comix.santa-cruz.ca.us> wrote:
> SMS <scharf.steven@geemail.com> hath wroth:
>
>>Powering a laptop computer would be a real accomplishment, I wouldn't
>>hold my breath waiting for that to happen.

>
> Minor trivia: Ever wonder how much power your laptop sucks? No need
> to measure it. Just look at the rating on the battery charger.
> Multiply volts times amps to get watts. The idea is that the battery
> charger is suppose to run the laptop with the battery removed. It can
> only do that if it has sufficient power capacity. Most of mine are
> around 40 watts. However, I've seen Toshiba desktop replacements with
> 120 watt power adapter and blow enough hot air to suspect all of it is
> being used.
>


Many supply enough power to power the laptop, with periphs AND charge the
battery. So, the power supply should significantly exceed the normal power
consumption.

--
Thomas T. Veldhouse
Key Fingerprint: D281 77A5 63EE 82C5 5E68 00E4 7868 0ADC 4EFB 39F0



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  #27 (permalink)  
Old 11-16-2006, 04:46 PM
John Navas
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Posts: n/a
Default Re: NEWS: Physics promises wireless power

On Thu, 16 Nov 2006 16:41:29 GMT, "Thomas T. Veldhouse"
<veldy71@yahoo.com> wrote in <Zw07h.93$%g1.36@fe01.usenetserver.com>:

>In alt.cellular.cingular John Navas <spamfilter0@navasgroup.com> wrote:
>>
>> While your concern is understandable, I think it's overdone -- the
>> physics make such side effects unlikely.

>
>They ALWAYS find out that they didn't account for something after millions of
>people have been exposed.


Not always. People have been ranting about RF harm for years without
any real justification.

>Considering the amount of energy in question here
>is significant when considering long term exposure, I don't think it can be so
>easily dismissed. Consider the fact that animal life has never in history
>been so exposed to radiation as the modern human has. Adding more energy to
>the mix is potentially more destructive so the frequency must be chosen wisely
>and tested carefully.


I respectfully suggest you read (and understand) the paper before
leaping to conclusions.

--
Best regards, FAQ FOR CINGULAR WIRELESS:
John Navas <http://en.wikibooks.org/wiki/Cingular_Wireless_FAQ>

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  #28 (permalink)  
Old 11-16-2006, 04:46 PM
Thomas T. Veldhouse
Guest
 
Posts: n/a
Default Re: NEWS: Physics promises wireless power

In alt.cellular.cingular SMS <scharf.steven@geemail.com> wrote:
>
> You also really don't know the maximum power the laptop consumes until
> you run a power virus program. You have to run these when you're doing
> worst case design of the laptops thermal solution and power supply
> components.
>


Or run Half-Life II. ;-)

--
Thomas T. Veldhouse
Key Fingerprint: D281 77A5 63EE 82C5 5E68 00E4 7868 0ADC 4EFB 39F0



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  #29 (permalink)  
Old 11-16-2006, 04:47 PM
John Navas
Guest
 
Posts: n/a
Default Re: NEWS: Physics promises wireless power

On Thu, 16 Nov 2006 16:41:55 GMT, "Thomas T. Veldhouse"
<veldy71@yahoo.com> wrote in <nx07h.94$%g1.54@fe01.usenetserver.com>:

>In alt.cellular.cingular SMS <scharf.steven@geemail.com> wrote:
>> Thomas T. Veldhouse wrote:
>>> In alt.cellular.cingular John Navas <spamfilter0@navasgroup.com> wrote:
>>>> <http://news.bbc.co.uk/2/hi/technology/6129460.stm>:
>>>
>>> I remember seeing this done with florescent light bulbs. It was an inspiring
>>> demonstration for elementary school students in the 70s.
>>>
>>> There are issues of concern. In the United States, electricity is transferred
>>> in the power grid at 60Hz.

>>
>> The local grid is 60 Hz, but the long distance power transmission is
>> high voltage DC.

>
>We had this discussion before. Some of it is.


Steven doesn't let facts get in the way of stuff he makes up.

--
Best regards, FAQ FOR CINGULAR WIRELESS:
John Navas <http://en.wikibooks.org/wiki/Cingular_Wireless_FAQ>

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  #30 (permalink)  
Old 11-16-2006, 04:47 PM
Thomas T. Veldhouse
Guest
 
Posts: n/a
Default Re: NEWS: Physics promises wireless power

In alt.cellular.cingular John Navas <spamfilter0@navasgroup.com> wrote:
> On Thu, 16 Nov 2006 06:51:52 -0800, SMS <scharf.steven@geemail.com>
> wrote in <455c7b04$0$88640$742ec2ed@news.sonic.net>:
>
>>Toshiba has Li-Ion batteries coming that can be fully charged in 10
>>minutes. The company claims that they will be out in 2008.

>
> [yawn] We've had 15 minute NiMH recharging for quite some time.
>


Yes, and it significantly decreases the life of the battery ... they simply
get too hot!

--
Thomas T. Veldhouse
Key Fingerprint: D281 77A5 63EE 82C5 5E68 00E4 7868 0ADC 4EFB 39F0



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