P
Phil Allison
Guest
"Shawn like a Sheep"
.... Phil
** Google the number - wanker.
.... Phil
P
Proteus IIV
Guest
On Nov 15, 1:31 pm, Fred Abse <excretatau...@invalid.invalid> wrote:
YES THERE ARE TWO KINDS OF ELECTRICITY BUT THEY ARE DIRECT AND
ALTERNATING
I AM PROTEUS
TROLL DROPPINGS
YES THERE ARE TWO KINDS OF ELECTRICITY BUT THEY ARE DIRECT AND
ALTERNATING
I AM PROTEUS
P
Proteus IIV
Guest
On Nov 15, 1:31 pm, Fred Abse <excretatau...@invalid.invalid> wrote:
I AM PROTEUS
TROPLL DROPPINGS
I AM PROTEUS
R
RFI-EMI-GUY
Guest
Jim Thompson wrote:
Prior to the LED days, Motorola once made radio dispatch consoles that
used incandescent lamps for PTT and channel activity call light. These
lamps were 24 VDC and turned on and off thousands of times. There was a
small resistor across the open collector driver to keep the lamps
slightly lit to prevent dmage to the lamp and the transistor driver.
--
Joe Leikhim K4SAT
"The RFI-EMI-GUY"Š
"Use only Genuine Interocitor Parts" Tom Servo ;-P
Prior to the LED days, Motorola once made radio dispatch consoles that
used incandescent lamps for PTT and channel activity call light. These
lamps were 24 VDC and turned on and off thousands of times. There was a
small resistor across the open collector driver to keep the lamps
slightly lit to prevent dmage to the lamp and the transistor driver.
--
Joe Leikhim K4SAT
"The RFI-EMI-GUY"Š
"Use only Genuine Interocitor Parts" Tom Servo ;-P
J
Jamie
Guest
Proteus IIV wrote:
J
Jim Thompson
Guest
On Mon, 16 Nov 2009 19:30:12 -0500, RFI-EMI-GUY
<Rhyolite@NETTALLY.COM> wrote:
(replacement for the motor/cam thingy) did that, then I went to a chip
driving SCR's... interruption the conventional bi-metal way.
...Jim Thompson
--
| James E.Thompson, CTO | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona 85048 Skype: Contacts Only | |
| Voice
480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |
Obama thinks the term "bully pulpit" actually means "pulpit bully"
<Rhyolite@NETTALLY.COM> wrote:
My first round design of the T-Bird sequential turn signals
(replacement for the motor/cam thingy) did that, then I went to a chip
driving SCR's... interruption the conventional bi-metal way.
...Jim Thompson
--
| James E.Thompson, CTO | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona 85048 Skype: Contacts Only | |
| Voice
480)460-2350 Fax: Available upon request | Brass Rat || E-mail Icon at http://www.analog-innovations.com | 1962 |
Obama thinks the term "bully pulpit" actually means "pulpit bully"
K
krw
Guest
On Mon, 16 Nov 2009 19:37:05 -0500, Jamie
<jamie_ka1lpa_not_valid_after_ka1lpa_@charter.net> wrote:
<jamie_ka1lpa_not_valid_after_ka1lpa_@charter.net> wrote:
You two are a perfect pair.
P
Paul G.
Guest
On Sun, 15 Nov 2009 11:05:48 +1100, "Phil Allison" <phil_a@tpg.com.au>
wrote:
LTSPICE, and look for saturation in the help menu it gives you the
details. One method is "based on a model first proposed in by John
Chan et la. in IEEE Transactions On Computer-Aided Design, Vol. 10.
No. 4, April 1991 but extended with the methods in United States
Patent 7,502,723". It uses Hc (Coercive force), Br (Remnant flux
density), Bs (Saturation flux density), Lm (Magnetic Length), Lg
(Length of gap), A (Cross sectional area), N (Number of turns). That
will be tricky for an inductor that's aready built.
The other method uses a "flux" statement:
L1 N001 0 Flux=1m*tanh(5*x)
I1 0 N001 PWL(0 0 1 1)
this didn't make a lot of sense to me..... Fortunately a search
came up with:
http://www.plcdrives.com/forum/f34/re-simulating-non-linear-magnetics-ltspice-29584/
which has a file that has many examples inside it to play with. It
explains how to set up different saturation scenarios. A quicky
simulation showed an enormous inrush current.
Another link which seems useful is:
http://ltwiki.org/index.php5?title=Main_Page (a WIKI for LTSpice)
more:
http://www.electronicskb.com/Uwe/Forum.aspx/design/45226/Inductor-saturation-in-LTspice
and another:
http://www.electronicskb.com/Uwe/Forum.aspx/cad/538/Simulating-non-linear-magnetics
whew! this is a lot of reading, and getting into the guts of
LTSpice. Many years ago, I used PSPice (the full release, that worked
under DOS, cost me well over $1000), it would do inductor saturation
as well.
Apparently the saturation models don't allow you to do mutual
coupling, so you need to make the transformer equivalent circuit in
which you can place the saturating inductance. There are details in
the above links.
Of course, it will be quite difficult to set up the parameters to do
a reasonable simulation, you need to know a lot about the device you
are simulating.
Paul G.
wrote:
LTSPICE has 2 methods for simulating saturation, if you run
LTSPICE, and look for saturation in the help menu it gives you the
details. One method is "based on a model first proposed in by John
Chan et la. in IEEE Transactions On Computer-Aided Design, Vol. 10.
No. 4, April 1991 but extended with the methods in United States
Patent 7,502,723". It uses Hc (Coercive force), Br (Remnant flux
density), Bs (Saturation flux density), Lm (Magnetic Length), Lg
(Length of gap), A (Cross sectional area), N (Number of turns). That
will be tricky for an inductor that's aready built.
The other method uses a "flux" statement:
L1 N001 0 Flux=1m*tanh(5*x)
I1 0 N001 PWL(0 0 1 1)
this didn't make a lot of sense to me..... Fortunately a search
came up with:
http://www.plcdrives.com/forum/f34/re-simulating-non-linear-magnetics-ltspice-29584/
which has a file that has many examples inside it to play with. It
explains how to set up different saturation scenarios. A quicky
simulation showed an enormous inrush current.
Another link which seems useful is:
http://ltwiki.org/index.php5?title=Main_Page (a WIKI for LTSpice)
more:
http://www.electronicskb.com/Uwe/Forum.aspx/design/45226/Inductor-saturation-in-LTspice
and another:
http://www.electronicskb.com/Uwe/Forum.aspx/cad/538/Simulating-non-linear-magnetics
whew! this is a lot of reading, and getting into the guts of
LTSpice. Many years ago, I used PSPice (the full release, that worked
under DOS, cost me well over $1000), it would do inductor saturation
as well.
Apparently the saturation models don't allow you to do mutual
coupling, so you need to make the transformer equivalent circuit in
which you can place the saturating inductance. There are details in
the above links.
Of course, it will be quite difficult to set up the parameters to do
a reasonable simulation, you need to know a lot about the device you
are simulating.
Paul G.
P
Phil Allison
Guest
"Paul G."
transformer - the results are always 100% trustworthy too.
..... Phil
** Takes far less time to simply measure what happens with a real
transformer - the results are always 100% trustworthy too.
..... Phil
J
Jim Yanik
Guest
Fester Bestertester <fbt@fbt.net> wrote in
news:0001HW.C7279C6F0007F514B08A39AF@news.eternal-september.org:
--
Jim Yanik
jyanik
at
localnet
dot com
news:0001HW.C7279C6F0007F514B08A39AF@news.eternal-september.org:
more turns on the pickup coil.
--
Jim Yanik
jyanik
at
localnet
dot com
B
bud--
Guest
Bill Sloman wrote:
Please ignore the ignorant troll that infests alt.engineering.electrical.
J
John Fields
Guest
On Tue, 17 Nov 2009 09:59:39 -0600, bud-- <remove.budnews@isp.com>
wrote:
Sloman posts there?
JF
wrote:
---
Sloman posts there?
JF
J
Jim Thompson
Guest
On Tue, 17 Nov 2009 12:13:41 -0600, John Fields
<jfields@austininstruments.com> wrote:
I'm always pleased to note that I'm the highest standard for Slowman's
disdain, but please don't feed the jerk. Let him die that most
unpleasant of deaths... alone ;-)
--
...Jim Thompson
| James E.Thompson, CTO | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona 85048 Skype: Contacts Only | |
| Voice480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |
<jfields@austininstruments.com> wrote:
Anywhere he can get an ego lift ;-)On Tue, 17 Nov 2009 09:59:39 -0600, bud-- <remove.budnews@isp.com
wrote:
Bill Sloman wrote:
Unhelpful abuse counts as a waste of bandwidth.
Raise you game or expect to be plonked.
Please ignore the ignorant troll that infests alt.engineering.electrical.
---
Sloman posts there?
JF
I'm always pleased to note that I'm the highest standard for Slowman's
disdain, but please don't feed the jerk. Let him die that most
unpleasant of deaths... alone ;-)
--
...Jim Thompson
| James E.Thompson, CTO | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona 85048 Skype: Contacts Only | |
| Voice
480)460-2350 Fax: Available upon request | Brass Rat || E-mail Icon at http://www.analog-innovations.com | 1962 |
J
Jan Panteltje
Guest
On a sunny day (Thu, 19 Nov 2009 03:43:15 -0500) it happened Yousuf Khan
<bbbl67@yahoo.com> wrote in <4b050521$1@news.bnb-lp.com>:
<bbbl67@yahoo.com> wrote in <4b050521$1@news.bnb-lp.com>:
G
Greegor
Guest
On Nov 19, 5:14 am, Jan Panteltje <pNaonStpealm...@yahoo.com> wrote:
Still not efficient enough.
ROI still lousy for cell phones/laptops.
Wouldn't current low efficiency ones be of
more benefit at larger heat sources?
Asphalt/concrete in hot sun?
Got a spec sheet for one of the current technology ones?
Do these work like Peltier units where it's
about a difference in temp?
Has anybody done hydroelectric power from downspouts?
http://www.sciencedaily.com/releases/2009/11/091118101403.htm
Harnessing Waste Heat from Laptop Computers,
Cell Phones May Double Battery Time
ScienceDaily (Nov. 19, 2009) In everything from computer processor
chips to car engines to electric powerplants, the need to get rid of
excess heat creates a major source of inefficiency. But new research
points the way to a technology that might make it possible to harvest
much of that wasted heat and turn it into usable electricity.
That kind of waste-energy harvesting might, for example, lead to
cellphones with double the talk time, laptop computers that can
operate twice as long before needing to be plugged in, or power plants
that put out more electricity for a given amount of fuel, says Peter
Hagelstein, co-author of a paper on the new concept appearing in
November in the Journal of Applied Physics.
Hagelstein, an associate professor of electrical engineering at MIT,
says existing solid-state devices to convert heat into electricity are
not very efficient. The new research, carried out with graduate
student Dennis Wu as part of his doctoral thesis, aimed to find how
close realistic technology could come to achieving the theoretical
limits for the efficiency of such conversion.
Theory says that such energy conversion can never exceed a specific
value called the Carnot Limit, based on a 19th-century formula for
determining the maximum efficiency that any device can achieve in
converting heat into work. But current commercial thermoelectric
devices only achieve about one-tenth of that limit, Hagelstein says.
In experiments involving a different new technology, thermal diodes,
Hagelstein worked with Yan Kucherov, now a consultant for the Naval
Research Laboratory, and coworkers to demonstrate efficiency as high
as 40 percent of the Carnot Limit. Moreover, the calculations show
that this new kind of system could ultimately reach as much as 90
percent of that ceiling.
Hagelstein, Wu and others started from scratch rather than trying to
improve the performance of existing devices. They carried out their
analysis using a very simple system in which power was generated by a
single quantum-dot device -- a type of semiconductor in which the
electrons and holes, which carry the electrical charges in the device,
are very tightly confined in all three dimensions. By controlling all
aspects of the device, they hoped to better understand how to design
the ideal thermal-to-electric converter.
Hagelstein says that with present systems it's possible to efficiently
convert heat into electricity, but with very little power. It's also
possible to get plenty of electrical power -- what is known as high-
throughput power -- from a less efficient, and therefore larger and
more expensive system. "It's a tradeoff. You either get high
efficiency or high throughput," says Hagelstein. But the team found
that using their new system, it would be possible to get both at once,
he says.
A key to the improved throughput was reducing the separation between
the hot surface and the conversion device. A recent paper by MIT
professor Gang Chen reported on an analysis showing that heat transfer
could take place between very closely spaced surfaces at a rate that
is orders of magnitude higher than predicted by theory. The new report
takes that finding a step further, showing how the heat can not only
be transferred, but converted into electricity so that it can be
harnessed.
A company called MTPV Corp. (for Micron-gap Thermal Photo-Voltaics),
founded by Robert DiMatteo SM '96, MBA '06, is already working on the
development of "a new technology closely related to the work described
in this paper," Hagelstein says.
DiMatteo says he hopes eventually to commercialize Hagelstein's new
idea. In the meantime, he says the technology now being developed by
his company, which he expects to have on the market next year, could
produce a tenfold improvement in throughput power over existing
photovoltaic devices, while the further advance described in this new
paper could make an additional tenfold or greater improvement
possible. The work described in this paper "is potentially a major
finding," he says.
DiMatteo says that worldwide, about 60 percent of all the energy
produced by burning fuels or generated in powerplants is wasted,
mostly as excess heat, and that this technology could "make it
possible to reclaim a significant fraction of that wasted energy."
When this work began around 2002, Hagelstein says, such devices
"clearly could not be built. We started this as purely a theoretical
exercise." But developments since then have brought it much closer to
reality.
While it may take a few years for the necessary technology for
building affordable quantum-dot devices to reach commercialization,
Hagelstein says, "there's no reason, in principle, you couldn't get
another order of magnitude or more" improvement in throughput power,
as well as an improvement in efficiency.
"There's a gold mine in waste heat, if you could convert it," he says.
The first applications are likely to be in high-value systems such as
computer chips, he says, but ultimately it could be useful in a wide
variety of applications, including cars, planes and boats. "A lot of
heat is generated to go places, and a lot is lost. If you could
recover that, your transportation technology is going to work better."
Still in RESEARCH stage.
Still not efficient enough.
ROI still lousy for cell phones/laptops.
Wouldn't current low efficiency ones be of
more benefit at larger heat sources?
Asphalt/concrete in hot sun?
Got a spec sheet for one of the current technology ones?
Do these work like Peltier units where it's
about a difference in temp?
Has anybody done hydroelectric power from downspouts?
http://www.sciencedaily.com/releases/2009/11/091118101403.htm
Harnessing Waste Heat from Laptop Computers,
Cell Phones May Double Battery Time
ScienceDaily (Nov. 19, 2009) In everything from computer processor
chips to car engines to electric powerplants, the need to get rid of
excess heat creates a major source of inefficiency. But new research
points the way to a technology that might make it possible to harvest
much of that wasted heat and turn it into usable electricity.
That kind of waste-energy harvesting might, for example, lead to
cellphones with double the talk time, laptop computers that can
operate twice as long before needing to be plugged in, or power plants
that put out more electricity for a given amount of fuel, says Peter
Hagelstein, co-author of a paper on the new concept appearing in
November in the Journal of Applied Physics.
Hagelstein, an associate professor of electrical engineering at MIT,
says existing solid-state devices to convert heat into electricity are
not very efficient. The new research, carried out with graduate
student Dennis Wu as part of his doctoral thesis, aimed to find how
close realistic technology could come to achieving the theoretical
limits for the efficiency of such conversion.
Theory says that such energy conversion can never exceed a specific
value called the Carnot Limit, based on a 19th-century formula for
determining the maximum efficiency that any device can achieve in
converting heat into work. But current commercial thermoelectric
devices only achieve about one-tenth of that limit, Hagelstein says.
In experiments involving a different new technology, thermal diodes,
Hagelstein worked with Yan Kucherov, now a consultant for the Naval
Research Laboratory, and coworkers to demonstrate efficiency as high
as 40 percent of the Carnot Limit. Moreover, the calculations show
that this new kind of system could ultimately reach as much as 90
percent of that ceiling.
Hagelstein, Wu and others started from scratch rather than trying to
improve the performance of existing devices. They carried out their
analysis using a very simple system in which power was generated by a
single quantum-dot device -- a type of semiconductor in which the
electrons and holes, which carry the electrical charges in the device,
are very tightly confined in all three dimensions. By controlling all
aspects of the device, they hoped to better understand how to design
the ideal thermal-to-electric converter.
Hagelstein says that with present systems it's possible to efficiently
convert heat into electricity, but with very little power. It's also
possible to get plenty of electrical power -- what is known as high-
throughput power -- from a less efficient, and therefore larger and
more expensive system. "It's a tradeoff. You either get high
efficiency or high throughput," says Hagelstein. But the team found
that using their new system, it would be possible to get both at once,
he says.
A key to the improved throughput was reducing the separation between
the hot surface and the conversion device. A recent paper by MIT
professor Gang Chen reported on an analysis showing that heat transfer
could take place between very closely spaced surfaces at a rate that
is orders of magnitude higher than predicted by theory. The new report
takes that finding a step further, showing how the heat can not only
be transferred, but converted into electricity so that it can be
harnessed.
A company called MTPV Corp. (for Micron-gap Thermal Photo-Voltaics),
founded by Robert DiMatteo SM '96, MBA '06, is already working on the
development of "a new technology closely related to the work described
in this paper," Hagelstein says.
DiMatteo says he hopes eventually to commercialize Hagelstein's new
idea. In the meantime, he says the technology now being developed by
his company, which he expects to have on the market next year, could
produce a tenfold improvement in throughput power over existing
photovoltaic devices, while the further advance described in this new
paper could make an additional tenfold or greater improvement
possible. The work described in this paper "is potentially a major
finding," he says.
DiMatteo says that worldwide, about 60 percent of all the energy
produced by burning fuels or generated in powerplants is wasted,
mostly as excess heat, and that this technology could "make it
possible to reclaim a significant fraction of that wasted energy."
When this work began around 2002, Hagelstein says, such devices
"clearly could not be built. We started this as purely a theoretical
exercise." But developments since then have brought it much closer to
reality.
While it may take a few years for the necessary technology for
building affordable quantum-dot devices to reach commercialization,
Hagelstein says, "there's no reason, in principle, you couldn't get
another order of magnitude or more" improvement in throughput power,
as well as an improvement in efficiency.
"There's a gold mine in waste heat, if you could convert it," he says.
The first applications are likely to be in high-value systems such as
computer chips, he says, but ultimately it could be useful in a wide
variety of applications, including cars, planes and boats. "A lot of
heat is generated to go places, and a lot is lost. If you could
recover that, your transportation technology is going to work better."
P
Phil Hobbs
Guest
Jan Panteltje wrote:
(Kelvin) temperature of the hot reservoir (e.g. the boiler in a steam
engine) and Tcold is that of the cold reservoir (the heat sink).
So if your computer is running at 50C and dumping heat at 30C (due to
the heat sink's inefficiency), the Carnot limit is 1-303K/323K = 6%.
Good luck doubling battery life with that.
Cheers
Phil Hobbs
--
Dr Philip C D Hobbs
Principal
ElectroOptical Innovations
55 Orchard Rd
Briarcliff Manor NY 10510
845-480-2058
hobbs at electrooptical dot net
http://electrooptical.net
Of course the Carnot limit is (1-Tcold/Thot), where Thot is the absolute
(Kelvin) temperature of the hot reservoir (e.g. the boiler in a steam
engine) and Tcold is that of the cold reservoir (the heat sink).
So if your computer is running at 50C and dumping heat at 30C (due to
the heat sink's inefficiency), the Carnot limit is 1-303K/323K = 6%.
Good luck doubling battery life with that.
Cheers
Phil Hobbs
--
Dr Philip C D Hobbs
Principal
ElectroOptical Innovations
55 Orchard Rd
Briarcliff Manor NY 10510
845-480-2058
hobbs at electrooptical dot net
http://electrooptical.net
J
Jim Thompson
Guest
On Thu, 19 Nov 2009 11:24:19 -0500, Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:
...Jim Thompson
--
| James E.Thompson, CTO | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona 85048 Skype: Contacts Only | |
| Voice480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |
If Bush was a MORON, what does that make Obama... an IMBECILE ?
<pcdhSpamMeSenseless@electrooptical.net> wrote:
You forgot the Obama multiplier ;-)
...Jim Thompson
--
| James E.Thompson, CTO | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona 85048 Skype: Contacts Only | |
| Voice
480)460-2350 Fax: Available upon request | Brass Rat || E-mail Icon at http://www.analog-innovations.com | 1962 |
If Bush was a MORON, what does that make Obama... an IMBECILE ?
P
Phil Hobbs
Guest
nuny@bid.nes wrote:
temperature gradient, e.g. across an article of clothing. You don't get
much power, but even a few tens of microwatts would be interesting for
some purposes.
Cheers
Phil Hobbs
--
Dr Philip C D Hobbs
Principal
ElectroOptical Innovations
55 Orchard Rd
Briarcliff Manor NY 10510
845-480-2058
hobbs at electrooptical dot net
http://electrooptical.net
There are energy scavenging techniques that can run off an ambient
temperature gradient, e.g. across an article of clothing. You don't get
much power, but even a few tens of microwatts would be interesting for
some purposes.
Cheers
Phil Hobbs
--
Dr Philip C D Hobbs
Principal
ElectroOptical Innovations
55 Orchard Rd
Briarcliff Manor NY 10510
845-480-2058
hobbs at electrooptical dot net
http://electrooptical.net
N
nuny@bid.nes
Guest
On Nov 19, 3:14 am, Jan Panteltje <pNaonStpealm...@yahoo.com> wrote:
is a screaming 6%, so they're bragging they can recover nearly 5.4%?
BFD.
modeled with microphones. Microphones only work because the sensing
element vibrates out of phase with a static element (the frame). Heat
jiggles both of them, randomly in and out of phase. Other power input
is required to damp the in-phase part (like running a Peltier junction
backwards). Otherwise, no net power. Period.
Mark L. Fergerson
As Phil Hobbs points out, the Carnot max at reasonable temperatures
is a screaming 6%, so they're bragging they can recover nearly 5.4%?
BFD.
Sorry, not gonna happen. Rectifying thermal energy can be better
modeled with microphones. Microphones only work because the sensing
element vibrates out of phase with a static element (the frame). Heat
jiggles both of them, randomly in and out of phase. Other power input
is required to damp the in-phase part (like running a Peltier junction
backwards). Otherwise, no net power. Period.
Mark L. Fergerson
D
Don Klipstein
Guest
In article <he39a5$5uo$1@news.datemas.de>, Jan Panteltje wrote:
the heat, how could increasing the fraction of that achievable allow
battery life to be doubled?
- Don Klipstein (don@misty.com)
Since the Carnot limit for low grade waste heat is a small percentage of
the heat, how could increasing the fraction of that achievable allow
battery life to be doubled?
- Don Klipstein (don@misty.com)