Help winding my own inductor?

[Don Klipstein]

In article <bvccuv4mcqjq3gleju5bu2b7t4uosc67nk@4ax.com>, DarkMatter wrote:

On Sun, 21 Dec 2003 20:06:51 +0000, Tim Auton <tim.auton@uton.[group
sex without the y on the end]> Gave us:

DarkMatter <DarkMatter@thebarattheendoftheuniverse.org> wrote:
[snip]
Look, chucko. WIre size doubles every three gauges. That is what I
said, and that is what is true.

In fact... Three 22s makes a 19, and three more makes another 19.

Two 19s doesn't even make one 16 so seven 22s is most certainly
closer to a single 16 than it is your lame assed 14 claim.

Please, move on to the 20th century (if you can't manage the 21st) and
use metres (mm in this case). This is the perfect example of why
metric is overwhelmingly superior to the array of units that
constitute that various imperial systems still in use in some parts of
the world.

They were nice when we had to do calculations in our heads. Those days
ended decades ago. Move on.

So, you are saying that 3 22 gauge wires does not make a 19 Gauge
wire?

Clarify. Then move the fuk on.

2 pieces of 22 makes a 19 in cross section area.

- Don Klipstein (don@misty.com)

 

[Keith R. Williams]

In article <6CR7mnC3Vg5$EwrJ@jmwa.demon.co.uk>,
jmw@jmwa.demon.contraspam.yuk says...

I read in sci.electronics.design that DarkMatter <DarkMatter@thebaratthe
endoftheuniverse.org> wrote (in <54obuv852g9t12b4126vte2udn44eme6st@4ax.
com&gt about 'Help winding my own inductor?', on Sun, 21 Dec 2003:
On Sun, 21 Dec 2003 17:09:03 +0000, John Woodgate
jmw@jmwa.demon.contraspam.yuk> Gave us:


'Litz' is short for the German word 'Litzendraht'. Being a German noun,
it starts with a capital letter. 'Litze' means 'lace', 'cord' or
'braid'. The strands of genuine Litz are interwoven in a specific way,
not just twisted or bunched.

Wrong. They MAY be woven, but generally are just twisted.

It works only for certain numbers of
strands, in the same way, roughly, as twisting works properly only for
7, 19, 37, 61, 97... etc. strands (numbers above 37 may be slightly
wrong).

Here you speak of perfect twisting. Which is it, boy, twisted or
woven?

It isn't worth discussing with you, because you are blatantly dishonest.
I wrote that Litz weaving works only for certain numbers of strands,
ROUGHLY as twisting...

LITZ is woven, not twisted.

John, I looked back through the patents on such things (I didn't
do a really thorough search). The earliest such thing I could
find was US1996186 by Affel (ATT), filed in 1932. It's not
described as "Litz" wire, but it does describe insulated twisted
wires, as well as better solutions (what is now known as "Litz").

--
Keith

 

[DarkMatter]

On Sun, 21 Dec 2003 18:16:41 -0600, John Fields
<jfields@austininstruments.com> Gave us:

On Sun, 21 Dec 2003 15:43:36 -0800, DarkMatter
DarkMatter@thebarattheendoftheuniverse.org> wrote:

On Sun, 21 Dec 2003 13:00:10 -0600, John Fields
jfields@austininstruments.com> Gave us:

On Sun, 21 Dec 2003 09:48:25 -0800, DarkMatter
DarkMatter@thebarattheendoftheuniverse.org> wrote:

On Sun, 21 Dec 2003 10:35:43 -0600, John Fields
jfields@austininstruments.com> Gave us:

But not because of the diminution of skin effect, unless you're talking
RF.


Skin effect is the exact reason. Again, I can place the same number
of turns at the SAME circular mil area onto a core and get different
performance at different operating frequencies, and said performance
is HIGHER on the multi-strand configurations, and the reason IS skin
effect.

Where have you been?

---
Watching you bury yourself.

I thought people only had two feet, but you seem to have a never-ending
supply of them you use to insert into your mouth.


Quoted from a reputable magnet wire maker:

"The multistrand configuration minimizes the power losses otherwise
encountered in a solid conductor due to the "skin effect", or the
tendency of radio frequency current to be concentrated at the surface
of the conductor."


You seem to have missed that I posted this, which is included in your
post, above:

"But not because of the diminution of skin effect, unless you're talking
RF."

Skin effect is measurable, and notable at lower than RF frequencies.

You must have also missed that there's no confict between what I posted
and what your "reputable magnet wire maker" posted, namely that skin
effect only becomes pronounced at radio frequencies (RF).

That depends on how one defines "pronounced". We save several
points on both final operating power factor, and overall efficiency at
full load.

In any case, regardless of what you may think, your seven-strand affair
is _not_ a piece of litz wire,

Yes, it is.

and will _never_ porform as well as litz
wire will at radio frequencies.

At RF Freqs it wi be like 17 or 39 57s or such. Hardly something I'd
wind my HV POWER switching transformers from.

You really ought to Google "skin effect" and find the relationship
between frequency and concentration of current in a conductor to find
out how really stupid the pseudo-knowledgeable spew you've been writng
makes you sound.

I'm sorry but ten inductors, each wound with one thru ten wires in
parallel, will exhibit skin effects when tested on pro equipment.

The frequency these skin effect differences in performance begin to
appear is much lower than RF frequencies... Sorry.

 

[DarkMatter]

On Sun, 21 Dec 2003 18:40:41 -0600, John Fields
<jfields@austininstruments.com> Gave us:

Fine, but you don't know that the stranded wire choke made it pass
because of anything having to do with skin effect.

Yes, I do.

 

[John Woodgate]

I read in sci.electronics.design that Paul Burridge
<pb@osiris1.notthisbit.co.uk> wrote (in <s11cuv83q63tma2ti3hg1a60ucn26at
to4@4ax.com&gt about 'Help winding my own inductor?', on Sun, 21 Dec
2003:

I've often wondered when winding these little toroids you get that are
only about an inch across what effect, if any, scraping off the wire's
enamel has on the finished job. I mean it would be tragic to end up
accidentally shorting turns out... But there again I don't think the
mateial they're made from is particularly conductive, is it?

Ferrites for frequencies below about 1 MHz are quite conductive.
Ferrites for higher frequencies have a different chemical composition
and are insulators.
--
Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk
Interested in professional sound reinforcement and distribution? Then go to
http://www.isce.org.uk
PLEASE do NOT copy news posts to me by E-MAIL!

 

[John Woodgate]

I read in sci.electronics.design that Keith R. Williams
<krw@attglobal.net> wrote (in <MPG.1a501a724e58611198a9b2@enews.newsguy.
com&gt about 'Help winding my own inductor?', on Sun, 21 Dec 2003:

John, I looked back through the patents on such things (I didn't
do a really thorough search). The earliest such thing I could
find was US1996186 by Affel (ATT), filed in 1932. It's not
described as "Litz" wire, but it does describe insulated twisted
wires, as well as better solutions (what is now known as "Litz").

The name 'Litzendraht' might just be a clue that the original patent is
German? And I guess that 1932 is about 30 years too late. Those huge
spark and alternator transmitters used very thick wires for their
inductors.
--
Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk
Interested in professional sound reinforcement and distribution? Then go to
http://www.isce.org.uk
PLEASE do NOT copy news posts to me by E-MAIL!

 

[John Woodgate]

I read in sci.electronics.design that John Popelish <jpopelish@rica.net>
wrote (in <3FE612E8.91427AD8@rica.net&gt about 'Help winding my own
inductor?', on Sun, 21 Dec 2003:

John Woodgate wrote:

John Fields wrote:

1000 times, no, John?

Z = n˛ through a transformer, but for an inductor, L changes linearly
with n.

Oh, no, John, no, John, no, John, no! Not if the turns are close-
coupled, as they are in a pot core.

How about if you adjust the gap to hold a constant flux for a given
current as you change the number of turns?

Then the inductance is *independent* of the number of turns, by the

definition of inductance (induction per unit current).
--
Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk
Interested in professional sound reinforcement and distribution? Then go to
http://www.isce.org.uk
PLEASE do NOT copy news posts to me by E-MAIL!

 

[YD]

On Sun, 21 Dec 2003 01:17:12 GMT, Spehro Pefhany
<speffSNIP@interlogDOTyou.knowwhat> wrote:

On Sun, 21 Dec 2003 01:50:24 GMT, the renowned jfields@texas.net (John
Fields) wrote:

On Sat, 20 Dec 2003 16:43:20 -0800, DarkMatter
DarkMatter@thebarattheendoftheuniverse.org> wrote:

On Sat, 20 Dec 2003 14:56:35 -0600, John Fields
jfields@austininstruments.com> Gave us:

Gapping a pot core is harder than gapping a toroid? Imagine that!!!

One doesn't gap these types of toroid.

---
Well, then, which types of toroids _does_ one gap?

http://www.mtroyal.ab.ca/eatingoncampus/images/timhortons.jpg

Best regards,
Spehro Pefhany

Damn, now you made me hungry.

- YD.

--
Remove HAT if replying by mail.

 

[John Fields]

On Sun, 21 Dec 2003 18:36:14 -0800, DarkMatter
<DarkMatter@thebarattheendoftheuniverse.org> wrote:

On Sun, 21 Dec 2003 18:40:41 -0600, John Fields
jfields@austininstruments.com> Gave us:

Fine, but you don't know that the stranded wire choke made it pass
because of anything having to do with skin effect.

Yes, I do.

---
Prove it.

 

[YD]

On Sun, 21 Dec 2003 08:27:36 +0000, John Woodgate
<jmw@jmwa.demon.contraspam.yuk> wrote:

I read in sci.electronics.design that DarkMatter <DarkMatter@thebaratthe
endoftheuniverse.org> wrote (in <car9uv0h7lm0d1d9arflkr2kk7146d2b7k@4ax.
com&gt about 'Help winding my own inductor?', on Sat, 20 Dec 2003:
On Sat, 20 Dec 2003 21:42:54 +0000, John Woodgate
jmw@jmwa.demon.contraspam.yuk> Gave us:

You can't make genuine Litz wire simply by twisting the strands
together. The interweaving pattern is a lot more complex.

You're nuts.

Au contraire.

Go to any wire maker's site. Litz wire is several
strands of finer pitch mag wire, all coated, that are either in
twisted, OR non-twisted configurations.

Anyone who is selling 'bunched' wire as litz is ripping you off. If
necessary, search for the original patent, whole reference I used to
have but I can't now find.

You can run ANY number of
parallel strands in a choke, and gain a litz advantage at even this
low (25kHz) frequency.

There are only certain numbers of strands that can be made into
*genuine* litz.

It is not woven.

Well, perhaps 'woven' is not quite the right word, but the strands are
not just twisted together.

That leans toward Litz Ribbon, however. An
interesting idea.

You must be thinking of the type of build the winding process on
some HF coils has.

Absolutely not. That's 'wave winding'.

First hit on askjeeves (Litz wire weaving):

http://www.litz-wire.com/applications.html

- YD.

--
Remove HAT if replying by mail.

 

[Keith R. Williams]

In article <fkNSvsAFSm5$EwtJ@jmwa.demon.co.uk>,
jmw@jmwa.demon.contraspam.yuk says...

I read in sci.electronics.design that Keith R. Williams
krw@attglobal.net> wrote (in <MPG.1a501a724e58611198a9b2@enews.newsguy.
com&gt about 'Help winding my own inductor?', on Sun, 21 Dec 2003:

John, I looked back through the patents on such things (I didn't
do a really thorough search). The earliest such thing I could
find was US1996186 by Affel (ATT), filed in 1932. It's not
described as "Litz" wire, but it does describe insulated twisted
wires, as well as better solutions (what is now known as "Litz").


The name 'Litzendraht' might just be a clue that the original patent is
German? And I guess that 1932 is about 30 years too late. Those huge
spark and alternator transmitters used very thick wires for their
inductors.

Perhaps. I was simply doing a search in the Delphion database
and filtered it back as far as the patent I referenced above.
That pretty much covered the interesting issues of such cable.
If there is a prior claim, I can't find it. A German name isn't
evidence of German origins.

--
Keith

 

[John Popelish]

John Woodgate wrote:

I read in sci.electronics.design that John Popelish <jpopelish@rica.net
wrote (in <3FE612E8.91427AD8@rica.net&gt about 'Help winding my own
inductor?', on Sun, 21 Dec 2003:
John Woodgate wrote:

John Fields wrote:

1000 times, no, John?

Z = n˛ through a transformer, but for an inductor, L changes linearly
with n.

Oh, no, John, no, John, no, John, no! Not if the turns are close-
coupled, as they are in a pot core.

How about if you adjust the gap to hold a constant flux for a given
current as you change the number of turns?

Then the inductance is *independent* of the number of turns, by the
definition of inductance (induction per unit current).

I have seen the definition of inductance as flux times area per
current (1 henry = (1 tesla * meter^2)/amp)) but this gives my mind a
snag. Perhaps you can straighten me out.

Lets say you have a large toroid core of infinite permeability with a
small air gap sawed through it, and 1 turn through the hole. I
measure the inductance and find x henries. So at 1 ampere, I have 1/2
x joules stored in the inductor and in the magnetic field in the air
volume of that gap. I then saw the gap to twice as wide and wind a
second turn through the hole, and get the same flux passing through
this thicker but same area air gap, and still measure x henries. So
by 1/2L*I^2 I still have the same energy stored in the inductor and in
the air volume in that gap, but there is now twice the original volume
of air stressed with the original flux. How can that be the same
total amount of magnetic energy?

--
John Popelish

 

[John Woodgate]

I read in sci.electronics.design that John Popelish <jpopelish@rica.net>
wrote (in <3FE67743.837598E8@rica.net&gt about 'Help winding my own
inductor?', on Mon, 22 Dec 2003:

I have seen the definition of inductance as flux times area per
current (1 henry = (1 tesla * meter^2)/amp)) but this gives my mind a
snag. Perhaps you can straighten me out.

The formula is L = N x [phi]/I, where N = number of turns, [phi] = flux
= flux density x area and I = current.

Lets say you have a large toroid core of infinite permeability with a
small air gap sawed through it, and 1 turn through the hole. I
measure the inductance and find x henries. So at 1 ampere, I have 1/2
x joules stored in the inductor and in the magnetic field in the air
volume of that gap. I then saw the gap to twice as wide and wind a
second turn through the hole, and get the same flux passing through
this thicker but same area air gap, and still measure x henries.

There are now two turns, so L = 2x. If you hadn't widened the gap, the
inductance would have been 4x.

So
by 1/2L*I^2 I still have the same energy stored in the inductor and in
the air volume in that gap, but there is now twice the original volume
of air stressed with the original flux. How can that be the same
total amount of magnetic energy?

It isn't. The inductance has doubled. From L = N[phi]/I, we get

L = NBA/I, B = induction, A = cross-sectional area

B = [mu]H, [mu] = permeability of air, H = magnetic field strength

and H = NI/l l = length of air-gap, since the rest of the circuit has
infinite permeability

So L = [mu]N^2IA/lI = [mu]N^2A/l

To get L back to its original value, with 2 turns instead of 1, we need
the gap to be 4 times longer.

If we then do a similar substitution for the stored energy:

LI^2/2 = (N[phi]I^2)/(2I) = N[phi]I/2 = N[mu]HAI/2 = N[mu](NI/l)AI/2

= [mu]/2 x N^2I^2A/l

N^2 has gone up 4 times and l has gone up 4 times, so the energy remains
the same. H, B and [phi] doubled due to the two turns, but dropped by a
factor of 4 due to the longer air-gap, giving a net halving.
--
Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk
Interested in professional sound reinforcement and distribution? Then go to
http://www.isce.org.uk
PLEASE do NOT copy news posts to me by E-MAIL!

 

[John Woodgate]

I read in sci.electronics.design that YD <yd.techHAT@techie.com> wrote
(in <77rcuv87qn1o3684rt77cjqbcsu8061fal@4ax.com&gt about 'Help winding my
own inductor?', on Mon, 22 Dec 2003:

First hit on askjeeves (Litz wire weaving):

http://www.litz-wire.com/applications.html

Bunched (untwisted) and purely twisted wires are offered by some
suppliers with the incorrect description 'Litz'. At least one supplier,
found by Google, lists these as "litz" wires.
--
Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk
Interested in professional sound reinforcement and distribution? Then go to
http://www.isce.org.uk
PLEASE do NOT copy news posts to me by E-MAIL!

 

[Airy R. Bean]

Litzendraht, ISTR.

"John Woodgate" <jmw@jmwa.demon.contraspam.yuk> wrote in message
news:beFzh2AmQs5$EwOh@jmwa.demon.co.uk...

I read in sci.electronics.design that YD <yd.techHAT@techie.com> wrote
(in <77rcuv87qn1o3684rt77cjqbcsu8061fal@4ax.com&gt about 'Help winding my
own inductor?', on Mon, 22 Dec 2003:

First hit on askjeeves (Litz wire weaving):

http://www.litz-wire.com/applications.html

Bunched (untwisted) and purely twisted wires are offered by some
suppliers with the incorrect description 'Litz'. At least one supplier,
found by Google, lists these as "litz" wires.
--
Regards, John Woodgate, OOO - Own Opinions Only.
http://www.jmwa.demon.co.uk
Interested in professional sound reinforcement and distribution? Then go
to
http://www.isce.org.uk
PLEASE do NOT copy news posts to me by E-MAIL!

 

[John Popelish]

John Woodgate wrote:

I read in sci.electronics.design that John Popelish <jpopelish@rica.net
wrote (in <3FE67743.837598E8@rica.net&gt about 'Help winding my own
inductor?', on Mon, 22 Dec 2003:

I have seen the definition of inductance as flux times area per
current (1 henry = (1 tesla * meter^2)/amp)) but this gives my mind a
snag. Perhaps you can straighten me out.

The formula is L = N x [phi]/I, where N = number of turns, [phi] = flux
= flux density x area and I = current.

Lets say you have a large toroid core of infinite permeability with a
small air gap sawed through it, and 1 turn through the hole. I
measure the inductance and find x henries. So at 1 ampere, I have 1/2
x joules stored in the inductor and in the magnetic field in the air
volume of that gap. I then saw the gap to twice as wide and wind a
second turn through the hole, and get the same flux passing through
this thicker but same area air gap, and still measure x henries.

There are now two turns, so L = 2x. If you hadn't widened the gap, the
inductance would have been 4x.

So
by 1/2L*I^2 I still have the same energy stored in the inductor and in
the air volume in that gap, but there is now twice the original volume
of air stressed with the original flux. How can that be the same
total amount of magnetic energy?

It isn't. The inductance has doubled. From L = N[phi]/I, we get

L = NBA/I, B = induction, A = cross-sectional area

B = [mu]H, [mu] = permeability of air, H = magnetic field strength

and H = NI/l l = length of air-gap, since the rest of the circuit has
infinite permeability

So L = [mu]N^2IA/lI = [mu]N^2A/l

To get L back to its original value, with 2 turns instead of 1, we need
the gap to be 4 times longer.

If we then do a similar substitution for the stored energy:

LI^2/2 = (N[phi]I^2)/(2I) = N[phi]I/2 = N[mu]HAI/2 = N[mu](NI/l)AI/2

= [mu]/2 x N^2I^2A/l

N^2 has gone up 4 times and l has gone up 4 times, so the energy remains
the same. H, B and [phi] doubled due to the two turns, but dropped by a
factor of 4 due to the longer air-gap, giving a net halving.

Does this answer contradict your last one?

I said, "How about if you adjust the gap to hold a constant flux for a
given
current as you change the number of turns?"

And you answered, "Then the inductance is *independent* of the number
of turns, by the definition of inductance (induction per unit
current)."

--
John Popelish

 

[John Woodgate]

I read in sci.electronics.design that John Popelish <jpopelish@rica.net>
wrote (in <3FE6DF82.4343BCE8@rica.net&gt about 'Help winding my own
inductor?', on Mon, 22 Dec 2003:

Does this answer contradict your last one?

I said, "How about if you adjust the gap to hold a constant flux for a
given
current as you change the number of turns?"

And you answered, "Then the inductance is *independent* of the number
of turns, by the definition of inductance (induction per unit
current)."

Yes. I misread your question to mean keeping N[phi] constant.
--
Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk
Interested in professional sound reinforcement and distribution? Then go to
http://www.isce.org.uk
PLEASE do NOT copy news posts to me by E-MAIL!

 

[R.Legg]

You must be thinking of the type of build the winding process on
some HF coils has.

Absolutely not. That's 'wave winding'.

I believe the correct term for this is 'progressive winding', when
applied to a coil structure.

RL

 

[John Woodgate]

I read in sci.electronics.design that R.Legg <legg@magma.ca> wrote (in
<e715b5cc.0312220541.5a9868cc@posting.google.com&gt about 'Help winding
my own inductor?', on Mon, 22 Dec 2003:

You must be thinking of the type of build the winding process on
some HF coils has.

Absolutely not. That's 'wave winding'.

I believe the correct term for this is 'progressive winding', when
applied to a coil structure.

There is wave winding and there is progressive wave winding, which is a

development of wave winding to make coils which are very long compared
with the diameter.

Progressive wave winding works by effectively mounting the waver wire
guide on a stock driven by a lead screw, so that the wave slowly creeps
along the former. When the desired length is reached, the lead screw
rotation reverses.

I didn't find any hits on Google, but I think I know who invented it. If
so, there should be a UK and a US patent dated in the early 1950s,
probably. Certainly, we had the machine in our model shop in 1958.
--
Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk
Interested in professional sound reinforcement and distribution? Then go to
http://www.isce.org.uk
PLEASE do NOT copy news posts to me by E-MAIL!

 

[John Fields]

On Mon, 22 Dec 2003 14:17:34 +0000, John Woodgate
<jmw@jmwa.demon.contraspam.yuk> wrote:

I read in sci.electronics.design that R.Legg <legg@magma.ca> wrote (in
e715b5cc.0312220541.5a9868cc@posting.google.com&gt about 'Help winding
my own inductor?', on Mon, 22 Dec 2003:
You must be thinking of the type of build the winding process on
some HF coils has.

Absolutely not. That's 'wave winding'.

I believe the correct term for this is 'progressive winding', when
applied to a coil structure.

There is wave winding and there is progressive wave winding, which is a
development of wave winding to make coils which are very long compared
with the diameter.

Progressive wave winding works by effectively mounting the waver wire
guide on a stock driven by a lead screw, so that the wave slowly creeps
along the former. When the desired length is reached, the lead screw
rotation reverses.

I didn't find any hits on Google, but I think I know who invented it. If
so, there should be a UK and a US patent dated in the early 1950s,
probably. Certainly, we had the machine in our model shop in 1958.

---


--
John Fields