Driver to drive?

[Jim Thompson]

On Wed, 27 Nov 2013 14:49:00 -0500, krw@attt.bizz wrote:

On Wed, 27 Nov 2013 09:32:51 -0700, Jim Thompson
To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote:

On Wed, 27 Nov 2013 08:14:12 -0800, Jeff Liebermann <jeffl@cruzio.com
wrote:

[snip]

Locally, the building inspectors are mostly failed independent
contractors, job creation beneficiaries, or amateur attorneys. While
many are amazingly competent, most have an agenda and a retaliatory
attitude. I've learned from experience not to mess with them as they
are quite capable of turning a minor remodel into a very expensive
house reconstruction project.

[snip]

One trick I learned when I went to get the permit to plumb 100 feet of
2.5" gas line to my pool heater... I played dumb and had the guy at
the permit counter draw up how I should do it

I've found that that strategy ("How do you want this done?") works,
but can be expensive. I built a garage, many moons ago. The
inspector made me put an 8" H-beam across the front, a steel-fire door
with a steel frame, and sheetrock the entire interior. He added over
a grand (>10%) to the cost of the project.

My situation wasn't that risky... I just wanted to make sure I used
the right fittings, etc. Turned out there _was_ a weird (to me) way
they wanted (what I thought to be Reub Goldberg) at the meter.

...Jim Thompson
--
| James E.Thompson | mens |
| Analog Innovations | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| San Tan Valley, AZ 85142 Skype: Contacts Only | |
| Voice480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |

I love to cook with wine. Sometimes I even put it in the food.

 

[Tim Williams]

Electrons are too heavily scattered at room temperature, and aren't
scattered with enough energy to notice. Thermal velocity is around 50
km/s (26meV), while electron drift velocity is on the order of 0.01 m/s
(depends on doping, charge density and current density), 10^5 times less.

Perhaps an extremely low temperature (i.e., 10^5 times less than 300K
ambient) would make the scattering more significant (however, scattering
is also thermally driven, which is why silicon resistors and FET channels
have a positive tempco), but you still need a semiconductor junction with
microvolt bandgap. That probably doesn't exist, or is too small (or too
tricky to tune by composition) to matter.

You might have more luck with a really fancy approach (which is to say,
not much), like, suppose the scattering could be made coherent, to make
coherent phonons (a phonon laser -- such a thing has been demonstrated).
Then suppose an acoustic multiplier could be made, to generate harmonics.
A few orders of magnitude later and the phonons will be on the order of
100s meV, potentially enough to play with at room temperature, or capture
with the help of a low bandgap semiconductor.

Tim

--
Seven Transistor Labs
Electrical Engineering Consultation
Website: http://seventransistorlabs.com

"Jamie M" <jmorken@shaw.ca> wrote in message
news:l769ka$cud$1@speranza.aioe.org...

Hi,

I was thinking of an alternative to superconductors to transmit
electricity with low (or zero) resistance. If there is a wire used
which has a fixed resistance but is able to regenerate some of the lost
energy that is lost to resistance, then it would have an effective
resistance that is lower. I think they key is to structure the wire
so the losses happen in a way that they can be regenerated. I was
thinking maybe something like a diode could work. ie. The wire would
be a stretched diode turned sideways, so that the P and N of the
diode are at the start of the wire and also the same P and N sections
are at the end of the wire. Then if the current is sent down the
interface of the diode between the P and N on the anode side, then if
there is resistance in the "wire", it will create phonons at the diode
junction, and they can be pumped by the diode back into the wire if the
cathode of the diode is routed back to the anode at the area that the
electrical loss occurs. Would something like this work? It is similar
to a solar panel for collecting electricity, but instead of using
photons from the sun, it is using phonons from electrical resistance
losses.

cheers,
Jamie

 

[P E Schoen]

"Tim Williams" wrote in message news:l74saa$guj$1@dont-email.me...

Waveform calculator:
http://schmidt-walter.eit.h-da.de/smps_e/smps_e.html

I found what appears to be an error in the calculation of wire size for the
primary. For my 48V 750W 50 kHz transformer it gives a primary of 7 turns of
1.82 mm (2.6 mm^2 or about #13 AWG) but the primary current is about 33 A
RMS which should be 11 mm^2 (about #6 AWG) at 3A/mm^2.

I have updated my calculator for multiple primary strands in parallel, with
appropriate skin effect calculation. I used 11 turns of 8 strands of #16 AWG
(same as secondary), and the primary losses are now about 6 watts instead of
15. Secondary is 138 turns and 15 watts losses. So the secondary would also
benefit from multiple strands.

http://enginuitysystems.com/files/Ferrite_Transformer.ods

Paul

 

[Lasse Langwadt Christense]

Den torsdag den 28. november 2013 18.54.18 UTC+1 skrev Robert Baer:

miso wrote:

He was interviewed on Democracy Now today.

http://www.democracynow.org/2013/11/27/my_family_has_been_separated_for

------------

JU HONG: "Sure. I was born and raised in South Korea until I was 11

years old. Our family owned a small Japanese restaurant in South Korea.

But, unfortunately, it did not really work out ďż˝ our business. We gave

up the business and we filed bankruptcy and one year after my mom and

dad decided to divorce and ever since then, I grew up with my mom and my

older sister, barely surviving our home country in South Korea. So, my

mom decided to move to the United States in 2001 to seek a better life

for me and my older sister. Ever since then I grew up just like many

other American students. I went to public school, spoke English, and

joined many different student activities. Most importantly, I had a

dream to go to college. But during my senior year in high school while I

was filling out my college applications, there was a section where it

requires citizenship status and Social Security number and I did not

know what to put. I asked my mom about it. That�s when she told me

everything about our immigration status, that we came here with a

tourist visa and she extended it for an additional six months, and

within 12 months, she tried to adjust our immigration status but it did

not work out, and we became undocumented."

-----------------

But you overstayed your visa. Isn't this exactly the type of people who

should be deported? You have fellow citizens who have applied to

immigrate to the US, and you are just trying to cut into the line.



Then he goes on to dis Janet Napalitano. OK, that sounds like a

redeeming quality. Basically, she sucked at her job, so go ahead and dis

her:

-------------------

JU HONG: "Well, Janet Napolitano does not fit into the president of the

UC system because of terrible record of what she has done to our

community. Because under her leadership, she deported 1.8 million

undocumented immigrant family members across the country. She is proud

of the fact that what she has done."

-------------------------

Uh, but that was her job. I was hoping he would complain about the TSA

nudie machines or the cavity searches. Or better yet, those damn VIPR

squads that are violating the constitution.



But alas, it gets worse, and not how you are thinking.

-------------------

JU HONG: I think the UC undocumented students are genuinely scared of

Janet Napolitano as the next president of the UC system and she doesn�t

have any leading position in the education. I think that ďż˝ she has tried

to, recently provided $5 million aid to undocumented immigrants, but I

think that is just political will for her to ease out the protesters and

try to make her image as a positive figure. But, the fact of the matter

is, the $5 million not substitute of how much pain that she caused for

our community. She will never substitute the pain and suffering and fear

that every single undocumented immigrant face that she has caused in our

community

-------------------------



What the fuck? She spent $5 million tax dollars to aid illegals going to

college. News to me. If true, she should be fired.



The Republic of Korea is not the kind of country where people persecute

each other. It is very homogenous. And the economy is cranking.



So they didn't risk life and limb crossing the desert, guided by

coyotes. Their country isn't a narco state with prejudice against those

without European blood. [Yeah, Mexico has its racism.] A lot of these

Mexicans are literally crossing the border as in running for their life

due to the drug wars.



Ju Hong's big mistake is he is a terrible poster boy for his cause. The

medium is the message, and he is a terrible medium. I have no idea if

this was planned or not, but they could have picked a more appropriate

messenger. You know, someone risking their life trying to escape poverty

and persecution. Lots of poor Mexicans die making that trip.



Dude, that was so not a plan!

WHEN the F will the citizens WAKE UP and demand that Congress uphold

the Constitution?

Kill the funding to the TSA and all related agencies; put their

"workers" on real jobs improving crumbling the transportation

infrastructure.

Plain fact of the matter is that the TSA *ARE* the terrorists!

I'm sure the TSA will be killed as soon as you come up with as much
campaign funding as the companies who make TSA gadgets do

so not very likely

and the TSA is just a nuisance it is the NSA that are really scary, but I guess they already have so much dirt on everyone that they can kill any attempt to
tame them

-Lasse

 

[Mook Johnson]

On 11/26/2013 9:49 PM, P E Schoen wrote:

I want to make a DC-DC converter for 48 VDC to about 300 VDC at a
continuous power of about 800W to drive a 1 to 2 HP three phase
induction motor.

1HP is ~ 750W. at 800 watts plus the efficiency if your 3 phase
inverter, you'll be pushing it for 1 HP let alone 2.

Also be careful of your input impedance. At 800W with 48V input and
assuming 80% efficiency (960W) you're looking at 20 amps input current
for an apparent input impedance of 2.4 ohms @ 48Vin. You need to be
sure your 48V source impedance (including cabling) has a total loop to
be less than 1/4th that value (0.6 ohms) Even that is critical at
something closer to 1/8th would be better. (.3 ohms) to deal with motor
load dymanics, startup surge etc.



I have some E55 cores and coilformers which should do

the job, and also some E47/20/15 which might work OK. The E55 is an
Epcos type N27 and the E47 is probably the same.

http://www.mouser.com/ds/2/136/e_47_20_16-75097.pdf
http://www.mouser.com/ds/2/136/e_55_28_21-73714.pdf

I found a website that shows a simple procedure to determine the turns
required for a transformer in a half-bridge topology using three
capacitors. I plan to use the same circuit but not use the additional
series capacitor and instead use two 20 uF 100 VAC PP capacitors in
series across the DC bus and the center to one end of the primary.

http://tahmidmc.blogspot.com/2013/02/ferrite-transformer-turns-calculation_22.html


The LTSpice for the basic circuit is on my server:
http://enginuitysystems.com/pix/48V-320V_DCDC_HalfBridge_2Cap.asc

I made a spreadsheet to automate the selection process and for the E55
core and 50 kHz it came up with 23 turns of #8 AWG for the primary at 33
amps and 144 turns of #16 for the secondary at 5.3 amps. It appears to
have 8 watts of ferrite losses and about 6 watts primary and secondary
copper losses for total efficiency of about 97%.

Here is the (OpenOffice) spreadsheet. Please have a look and see if it
is at least close to being accurate:
http://enginuitysystems.com/files/Ferrite_Transformer.ods

Another question I have is if would be helpful to use heat shrink tape
to compress the ferrite halves:
http://www.mcmaster.com/#heat-shrink-tape/=pjzuzt

I would suggest glue. regular tape would serve to keep the cures
together for testing but once it is ready for prime time I would glue
the to core halves together. You don't want to put glue between the
core halves. Just a ring around the outside of the cut. 5 minute epoxy
or something similar would suffice as long as it adheres to ferrite.
Make sure you clean them with alcohol before gluing to remove oils and
films.

And, finally, I think it would be good to use Litz wire for this. I
found some that seems to be a good deal:
http://www.ebay.com/itm/370951676185

Thanks,

Paul

Litz is OK but make sure it is the solder through type of insulation.
Otherwise stripping the ends is a pain.

You can also go multifilar smaller gauge instead of litz to get the
turns to law down in the bobbin with less wasted space between the turns.

 

[Maynard A. Philbrook Jr.]

In article <l76ve3$kh4$1@dont-email.me>, paul@peschoen.com says...

"Tim Williams" wrote in message news:l74saa$guj$1@dont-email.me...

Waveform calculator:
http://schmidt-walter.eit.h-da.de/smps_e/smps_e.html

I found what appears to be an error in the calculation of wire size for the
primary. For my 48V 750W 50 kHz transformer it gives a primary of 7 turns of
1.82 mm (2.6 mm^2 or about #13 AWG) but the primary current is about 33 A
RMS which should be 11 mm^2 (about #6 AWG) at 3A/mm^2.

I have updated my calculator for multiple primary strands in parallel, with
appropriate skin effect calculation. I used 11 turns of 8 strands of #16 AWG
(same as secondary), and the primary losses are now about 6 watts instead of
15. Secondary is 138 turns and 15 watts losses. So the secondary would also
benefit from multiple strands.

http://enginuitysystems.com/files/Ferrite_Transformer.ods

Paul

Litz wire would be a great choice, expensive as hell for your size
however

We have a resource of copper tape at work and can run that through the
lacquer process. Works well for high freq apps and high current.
Jamie

 

[Bill Sloman]

On Friday, 29 November 2013 07:02:18 UTC+11, Lasse Langwadt Christensen wrote:

Den torsdag den 28. november 2013 18.54.18 UTC+1 skrev Robert Baer:
miso wrote:

<snip>

Dude, that was so not a plan!

WHEN the F will the citizens WAKE UP and demand that Congress uphold the Constitution?

Kill the funding to the TSA and all related agencies; put their "workers" on real jobs improving crumbling the transportation infrastructure.

Plain fact of the matter is that the TSA *ARE* the terrorists!

I'm sure the TSA will be killed as soon as you come up with as much campaign funding as the companies who make TSA gadgets do so not very likely and the TSA is just a nuisance. It is the NSA that are really scary, but I guess they already have so much dirt on everyone that they can kill any attempt to tame them.

It's a strategy that worked for J Edgar Hoover. Nobody ever dared to point out that he was gay until after he was safely dead - the FBI always spent a lot of it's time documenting the sexual activities of prominent Americans, so the Hoover could blackmail them if they tried to blackmail him.

--
Bill Sloman, Sydney

 

[Robert Baer]

miso wrote:

He was interviewed on Democracy Now today.
http://www.democracynow.org/2013/11/27/my_family_has_been_separated_for
------------
JU HONG: "Sure. I was born and raised in South Korea until I was 11
years old. Our family owned a small Japanese restaurant in South Korea.
But, unfortunately, it did not really work out — our business. We gave
up the business and we filed bankruptcy and one year after my mom and
dad decided to divorce and ever since then, I grew up with my mom and my
older sister, barely surviving our home country in South Korea. So, my
mom decided to move to the United States in 2001 to seek a better life
for me and my older sister. Ever since then I grew up just like many
other American students. I went to public school, spoke English, and
joined many different student activities. Most importantly, I had a
dream to go to college. But during my senior year in high school while I
was filling out my college applications, there was a section where it
requires citizenship status and Social Security number and I did not
know what to put. I asked my mom about it. That’s when she told me
everything about our immigration status, that we came here with a
tourist visa and she extended it for an additional six months, and
within 12 months, she tried to adjust our immigration status but it did
not work out, and we became undocumented."
-----------------
But you overstayed your visa. Isn't this exactly the type of people who
should be deported? You have fellow citizens who have applied to
immigrate to the US, and you are just trying to cut into the line.

Then he goes on to dis Janet Napalitano. OK, that sounds like a
redeeming quality. Basically, she sucked at her job, so go ahead and dis
her:
-------------------
JU HONG: "Well, Janet Napolitano does not fit into the president of the
UC system because of terrible record of what she has done to our
community. Because under her leadership, she deported 1.8 million
undocumented immigrant family members across the country. She is proud
of the fact that what she has done."
-------------------------
Uh, but that was her job. I was hoping he would complain about the TSA
nudie machines or the cavity searches. Or better yet, those damn VIPR
squads that are violating the constitution.

But alas, it gets worse, and not how you are thinking.
-------------------
JU HONG: I think the UC undocumented students are genuinely scared of
Janet Napolitano as the next president of the UC system and she doesn’t
have any leading position in the education. I think that — she has tried
to, recently provided $5 million aid to undocumented immigrants, but I
think that is just political will for her to ease out the protesters and
try to make her image as a positive figure. But, the fact of the matter
is, the $5 million not substitute of how much pain that she caused for
our community. She will never substitute the pain and suffering and fear
that every single undocumented immigrant face that she has caused in our
community
-------------------------

What the fuck? She spent $5 million tax dollars to aid illegals going to
college. News to me. If true, she should be fired.

The Republic of Korea is not the kind of country where people persecute
each other. It is very homogenous. And the economy is cranking.

So they didn't risk life and limb crossing the desert, guided by
coyotes. Their country isn't a narco state with prejudice against those
without European blood. [Yeah, Mexico has its racism.] A lot of these
Mexicans are literally crossing the border as in running for their life
due to the drug wars.

Ju Hong's big mistake is he is a terrible poster boy for his cause. The
medium is the message, and he is a terrible medium. I have no idea if
this was planned or not, but they could have picked a more appropriate
messenger. You know, someone risking their life trying to escape poverty
and persecution. Lots of poor Mexicans die making that trip.

Dude, that was so not a plan!

WHEN the F will the citizens WAKE UP and demand that Congress uphold
the Constitution?
Kill the funding to the TSA and all related agencies; put their
"workers" on real jobs improving crumbling the transportation
infrastructure.
Plain fact of the matter is that the TSA *ARE* the terrorists!

 

[hamilton]

On 11/28/2013 10:54 AM, Robert Baer wrote:

Plain fact of the matter is that the TSA *ARE* the terrorists!

So, their plan DID work.

 

[Gib Bogle]

On 29/11/2013 6:54 a.m., Robert Baer wrote:

WHEN the F will the citizens WAKE UP and demand that Congress uphold
the Constitution?
Kill the funding to the TSA and all related agencies; put their
"workers" on real jobs improving crumbling the transportation
infrastructure.
Plain fact of the matter is that the TSA *ARE* the terrorists!

Home of the free, land of the brave! baa-baa

 

[amdx]

On 11/28/2013 2:38 AM, P E Schoen wrote:

"Tim Williams" wrote in message news:l74saa$guj$1@dont-email.me...

Waveform calculator:
http://schmidt-walter.eit.h-da.de/smps_e/smps_e.html

I found what appears to be an error in the calculation of wire size for
the primary. For my 48V 750W 50 kHz transformer it gives a primary of 7
turns of 1.82 mm (2.6 mm^2 or about #13 AWG) but the primary current is
about 33 A RMS which should be 11 mm^2 (about #6 AWG) at 3A/mm^2.

I have updated my calculator for multiple primary strands in parallel,
with appropriate skin effect calculation. I used 11 turns of 8 strands
of #16 AWG (same as secondary), and the primary losses are now about 6
watts instead of 15. Secondary is 138 turns and 15 watts losses. So the
secondary would also benefit from multiple strands.

http://enginuitysystems.com/files/Ferrite_Transformer.ods

Paul

I'm confused by your wire description.
You said,

I used 11 turns of 8 strands
of #16 AWG (same as secondary)

Does this mean no Litz wire?
I have wound transformers and inductors
with as many as four strands paralleled,
that helped reduce heat vs. a single larger wire.
I never wound any with Litz.

A 38 Gauge 66 strand litz is the same diameter as
a 16 gauge solid wire.
I'd like to see the equivalent Rac of 8 solid 16 Gauge vs.
8 litz 38/66. They should be equal size.
Mikek

Useful formulas here:
newenglandwire.com/products/litz-and-formed-cables/theory.aspx

 

[miso]

On 11/28/2013 12:02 PM, Lasse Langwadt Christensen wrote:

I'm sure the TSA will be killed as soon as you come up with as much
campaign funding as the companies who make TSA gadgets do

so not very likely

and the TSA is just a nuisance it is the NSA that are really scary, but
I guess they already have so much dirt on everyone that they can kill any attempt to
tame them

-Lasse

Two words: Chertoff Group
http://www.chertoffgroup.com/

Well at least the poorly calibrated Xray nudie machines are gone. Now we
just have the millimeter wave nudie machines, which of course don't scan
body cavities of either flavor nor any situation where skin sits on top
of skin, AKA large floppy breasts or beer bellies. Oh, and turbans need
not be removed, yet they can't be accurately examined by the millimeter
wave scanner and of course we no longer use magnetometers, so metal
could be hidden in one. Even the hair bumps the aren't examined. (Hair
bump as in Flo the Progressive Insurance women.)

 

[Jamie M]

On 11/28/2013 12:05 AM, Tim Williams wrote:

Electrons are too heavily scattered at room temperature, and aren't
scattered with enough energy to notice. Thermal velocity is around 50
km/s (26meV), while electron drift velocity is on the order of 0.01 m/s
(depends on doping, charge density and current density), 10^5 times less.

Perhaps an extremely low temperature (i.e., 10^5 times less than 300K
ambient) would make the scattering more significant (however, scattering
is also thermally driven, which is why silicon resistors and FET channels
have a positive tempco), but you still need a semiconductor junction with
microvolt bandgap. That probably doesn't exist, or is too small (or too
tricky to tune by composition) to matter.

You might have more luck with a really fancy approach (which is to say,
not much), like, suppose the scattering could be made coherent, to make
coherent phonons (a phonon laser -- such a thing has been demonstrated).
Then suppose an acoustic multiplier could be made, to generate harmonics.
A few orders of magnitude later and the phonons will be on the order of
100s meV, potentially enough to play with at room temperature, or capture
with the help of a low bandgap semiconductor.

Tim

Hi,

Thanks thats interesting, I think a "phonon standing wave" that keeps
the electrons lined up and travelling straight with no losses could work
maybe. Maybe a dual bandgap (cathode to cathode diode) with the
electrons confined to travel only in the cathode area to hold them
locked into that straight path down the wire.

cheers,
Jamie

 

[Neon John]

On Thu, 28 Nov 2013 12:34:50 -0500, "Maynard A. Philbrook Jr."
<jamie_ka1lpa@charter.net> wrote:

Litz wire would be a great choice, expensive as hell for your size
however

We (www.fluxeon.com) use Litz wire in our induction heaters. We also
sell small quantities to the public as a service since it is so hard
to get in small quantities. We have some huge #4 equivalent stuff if
you need it. Just go to the web site, to the store and buy what you
need by the foot.

John
John DeArmond
http://www.neon-john.com
http://www.fluxeon.com
Tellico Plains, Occupied TN
See website for email address

 

[P E Schoen]

"Neon John" wrote in message
newstah99dprcht9km6sehk5u2o7vgg6plika@4ax.com...

We (www.fluxeon.com) use Litz wire in our induction heaters. We
also sell small quantities to the public as a service since it is so
hard to get in small quantities. We have some huge #4 equivalent
stuff if you need it. Just go to the web site, to the store and buy
what you need by the foot.

I checked the website and they also offer 7x52/38 which is equivalent to #10
AWG and rated for about 17 amps at 600 CM/A (3.3 A/mm^2). It's listed at
$1.13 while the larger size 7x7x52/38 is $8.31. That should be good for
17*7= 119 amps which is equivalent to #4 at 350 CM/A (which may be too much
for continuous duty in a transformer core).

The website does not say that the price is per foot. I figure I will need
about 8 ft for two primaries of 11 turns, which would cost about $9 plus
shipping, which is a $15 flat rate (which was not stated until checkout). So
my cost would be $24.

I could use the 7x3x21/40 Litz wire I found on eBay for $20/40 ft with free
shipping. This is rated for about 7.8 amps, so I would need twice as much,
or 16 ft. But for $20 I would have enough for two transformers.

Thanks for the link. It seems like a good source for induction heaters if I
ever have the need.

Paul

 

[Bill Sloman]

On Saturday, 30 November 2013 20:14:18 UTC+11, John Fields wrote:

On Sat, 30 Nov 2013 00:45:30 -0800 (PST), Bill Sloman
bill.sloman@gmail.com> wrote:
On Saturday, 30 November 2013 05:10:54 UTC+11, Maynard A. Philbrook Jr. wrote:
In article <1971e739-797f-4301-bb39-586456362f98@googlegroups.com>,
bill.sloman@gmail.com says...
On Saturday, 30 November 2013 00:11:34 UTC+11, Maynard A. Philbrook Jr. wrote:
In article <l79915$bmq$1@dont-email.me>, hamilton@nothere.com says....
On Friday, 29 November 2013 11:34:01 UTC+11, Greegor wrote:
On Thursday, November 28, 2013 3:35:29 PM UTC-6, hamilton wrote:

snip

It's one thing to ask for facts, but ignoring the facts that you have been given and continuing to bleat as if you hadn't had a reply creates a rather different, and - sadly - more accurate, impression.

Bla bla Bla,,

Word games, you'd make a perfect politician.

You asked for facts. I gave you facts.

It's you who is playing word games - so obviously that you clearly wouldn't qualify as a politician. They take care to lie plausibly.

Then you'll be running for public office soon?

I'm disqualified. I don't lie at all. I may mislead my readers, but I don't do it intentionally. I may be unintentionally misleading you here, by constructing a sentence which is too complex for you to parse reliably, but I'm fairly sure that this one lies inside your processing capability, possibly even Jamie's, though he does seem to skip stuff that he doesn't want to process.

--
Bill Sloman, Sydney

 

[John Fields]

On Sat, 30 Nov 2013 00:45:30 -0800 (PST), Bill Sloman
<bill.sloman@gmail.com> wrote:

On Saturday, 30 November 2013 05:10:54 UTC+11, Maynard A. Philbrook Jr. wrote:
In article <1971e739-797f-4301-bb39-586456362f98@googlegroups.com>,
bill.sloman@gmail.com says...
On Saturday, 30 November 2013 00:11:34 UTC+11, Maynard A. Philbrook Jr. wrote:
In article <l79915$bmq$1@dont-email.me>, hamilton@nothere.com says...
On Friday, 29 November 2013 11:34:01 UTC+11, Greegor wrote:
On Thursday, November 28, 2013 3:35:29 PM UTC-6, hamilton wrote:

snip

It's one thing to ask for facts, but ignoring the facts that you have been given and continuing to bleat as if you hadn't had a reply creates a rather different, and - sadly - more accurate, impression.

Bla bla Bla,,

Word games, you'd make a perfect politician.

You asked for facts. I gave you facts.

It's you who is playing word games - so obviously that you clearly wouldn't qualify as a politician. They take care to lie plausibly.

---
Then you'll be running for public office soon?

 

[John Fields]

On Sat, 30 Nov 2013 00:57:19 -0800 (PST), Bill Sloman
<bill.sloman@gmail.com> wrote:

On Saturday, 30 November 2013 09:57:12 UTC+11, k...@attt.bizz wrote:
On Thu, 28 Nov 2013 21:28:22 -0800 (PST), Bill Sloman
bill.sloman@gmail.com> wrote:
On Friday, 29 November 2013 11:34:01 UTC+11, Greegor wrote:
On Thursday, November 28, 2013 3:35:29 PM UTC-6, hamilton wrote:

snip

Unlike right-wingers, left wing sources don't lie

As posted by krw

"Unlike right-wingers, left wing sources don't lie - they don't have to."

What I actually posted.

Slowman, you get funnier by the day. Your nose must be four meters long by now.

krw snipped the last four words of the sentence I posted and didn't mark the snip. That's know as "text-chopping", by people who study this kind of stuff.

Need I say more?

---
No, but much to your chagrin, you will.

 

[Bill Sloman]

On Sunday, 1 December 2013 01:33:51 UTC+11, k...@attt.bizz wrote:

On Sat, 30 Nov 2013 00:57:19 -0800 (PST), Bill Sloman
bill.sloman@gmail.com> wrote:
On Saturday, 30 November 2013 09:57:12 UTC+11, k...@attt.bizz wrote:
On Thu, 28 Nov 2013 21:28:22 -0800 (PST), Bill Sloman
bill.sloman@gmail.com> wrote:
On Friday, 29 November 2013 11:34:01 UTC+11, Greegor wrote:
On Thursday, November 28, 2013 3:35:29 PM UTC-6, hamilton wrote:

snip

Unlike right-wingers, left wing sources don't lie

As posted by krw

"Unlike right-wingers, left wing sources don't lie - they don't have to."

What I actually posted.

The point is the same, Slowman. You're a liar, just like your "left
wing sources". What a dumbshit.

You don't perceive the difference in meaning, so you are making a false assertion, which you lack the wit to perceive to be false. No wonder you find so much of what passes over your head to be lies and dumb shit.

Slowman, you get funnier by the day. Your nose must be four meters long by now.

krw snipped the last four words of the sentence I posted and didn't mark the snip. That's know as "text-chopping", by people who study this kind of stuff.

Those last four words don't change the meaning. It's one of the stupidest things you've said, Slowman.

The stupidity lies entirely in your assertion that they don't change the meaning. Like I said, it's text-chopping, and you are too dim appreciate that this isn't an honest form of argument.

> English isn't your first language, is it Slowman? No need to answer - your illiteracy is clear.

Someone with only a slightly stronger grasp of the meaning of words would appreciate the irony of accusing someone of illiteracy in writing.

http://www.merriam-webster.com/dictionary/illiteracy

Need I say more?

Please don't. I'm laughing hard enough to hurt as it is.

It's sad that the joke is on you, and you won't be able to get it. Still, it makes it a little funnier for the rest of us.

--
Bill Sloman, Sydney

 

[P E Schoen]

"Phil Hobbs" wrote in message
news:8fKdncAw8Lc99QTPnZ2dnUVZ_qadnZ2d@supernews.com...

The skin effect explanation for Litz wire is wrong all through. If it
were correct, Litz would be lossier than solid, because in solid
wire, at least the current has a straight shot on the thin outside
layer, whereas with Litz, all of it spends a lot of time inside the
bundle.

The skin effect argument is far from straightforward in the presence
of other conductors, and especially of ferrite cores. You can't just
take the 1-D isolated conductor result and wave it over the design
like a dead chicken.

The actual benefit is due to reducing eddy current loss in the wire
due to dB/dt. Copper tape winding is about equally effective IIRC.

Very interesting. Is there any data available showing the real performance
of Litz wire vs single thick strand and multifilar coils? I also wonder
about the Lorentz force, which tends to press together parallel conductors
with current flowing in the same direction, so it seems that the current may
tend to try to flow more in the center. And there is a lot of distributed
capacitance among all those isolated conductors, so at high frequency there
may be some current flow among coils at different potentials.

The eddy current loss reduction makes sense, and the Litz wire may be
analogous to thin insulated laminations in transformers and motors designed
for higher frequencies.

I think I will order some of the Litz wire, as it seems that it will help
reduce the power dissipation and hence temperature, and it may be easier to
wind. But my first prototype will probably be with just multifilar windings.
In fact, I made a smaller transformer with an inner secondary winding of
about 145 turns of #26, and an outer primary winding with 8 turns of 2
parallel #17 and 2 parallel #18. I just reused this wire that was on a
computer power supply transformer good for about 400 watts.

I tried to test it using my HP 3312A function generator, but it does not
drive the primary very well, although it seems to do OK at 300 kHz. I will
need to rig up a proper drive circuit using the push-pull 2 capacitor
topology.

Thanks for the information.

Paul