Anyone got a complete DC B-H initial curve and loop for GOSS, or
link to same? I need scale and enough detail to extract data for
regression.

M4 or M2 would be best.

Suggestions as to the best function to fit to the initial curve
would be appreciated too. Ideally it should be continuous through
the origin, and be symmetrical in first and third quadrants,
asymptotic to B/H = µ0, and get close to the initial curve from the
origin. Wish I had paid more attention to statistical distributions
at school coz I suspect that's what is needed.

BTW, with reference to earlier contributions on core losses, I find
frequent reference to skin effect in windings, and its equivalent in
the magnetic circuit of the core, but I haven't found any data.

Also BTW, what are we going to do for transformers when everyone
else is using switched mode for everything? Will GOSS sheet become
hard to find? I gather for large transformers in power grids,
amorphous is being dumped on the "third world" because it is not
much good, so perhaps GOSS has a secure future there.

cheers, Ian

On Thu, 31 Mar 2005 10:56:07 GMT, "Ian Iveson"
wrote:

Anyone got a complete DC B-H initial curve and loop for GOSS, or
link to same? I need scale and enough detail to extract data for
regression.

M4 or M2 would be best.

Suggestions as to the best function to fit to the initial curve
would be appreciated too. Ideally it should be continuous through
the origin, and be symmetrical in first and third quadrants,
asymptotic to B/H = µ0, and get close to the initial curve from the
origin. Wish I had paid more attention to statistical distributions
at school coz I suspect that's what is needed.

BTW, with reference to earlier contributions on core losses, I find
frequent reference to skin effect in windings, and its equivalent in
the magnetic circuit of the core, but I haven't found any data.

Also BTW, what are we going to do for transformers when everyone
else is using switched mode for everything? Will GOSS sheet become
hard to find? I gather for large transformers in power grids,
amorphous is being dumped on the "third world" because it is not
much good, so perhaps GOSS has a secure future there.

cheers, Ian

You can go to www.tempel.com and get the data on
all grades of steel including grain oriented steel.

Jerry

Ian Iveson wrote:

Anyone got a complete DC B-H initial curve and loop for GOSS, or
link to same? I need scale and enough detail to extract data for
regression.

M4 or M2 would be best.

Suggestions as to the best function to fit to the initial curve
would be appreciated too. Ideally it should be continuous through
the origin, and be symmetrical in first and third quadrants,
asymptotic to B/H = µ0, and get close to the initial curve from the
origin. Wish I had paid more attention to statistical distributions
at school coz I suspect that's what is needed.

BTW, with reference to earlier contributions on core losses, I find
frequent reference to skin effect in windings, and its equivalent in
the magnetic circuit of the core, but I haven't found any data.

Also BTW, what are we going to do for transformers when everyone
else is using switched mode for everything? Will GOSS sheet become
hard to find? I gather for large transformers in power grids,
amorphous is being dumped on the "third world" because it is not
much good, so perhaps GOSS has a secure future there.

cheers, Ian

SMPS are not entirely dominating designs for PS
or causing dramatic falls in GOSS production.

It has become routine for steel companies to make decent GOSS,
and its real price is cheaper than ever before.
It is in demand because it is cost effective against non oriented iron
with higher losses
where weight is an issue, like in an amp or microwave oven for export,
and it does not have to be interleaved when a tranny is wound; butting
and machine welding
is a cheaper more effective mass manufacturing method.

There are millions of tones of inductors used in lighting, flurescents
and
sodium street lights use inductors.
Thre there are all the electric motors which need GOSS to run cooler,
and
be lighter.
So GOSS will be around for awhile since there is little that can
replace it.

Curves and properties of GOSS is at a few websites if you search.
Its not easy to understand all data you find.

Better to compare measurements with differently cored OPTs to
find out what happens at extremes of F.

Patrick Turner.

e

"Gerald Stombaugh" wrote
You can go to www.tempel.com and get the data on
all grades of steel including grain oriented steel.

Unfortunately not. I've searched for ages. Perhaps I will email one
of the suppliers.

Tempel only goes to M6, BTW.

cheers, Ian.

"Patrick Turner" wrote

Curves and properties of GOSS is at a few websites if you search.

An example would be useful. I wouldn't have asked if I hadn't looked
already.

Its not easy to understand all data you find.

The principles are nice and simple, but not so easy to model as an
electrical circuit. The main problem is finding detailed data
measured under stated conditions.

Better to compare measurements with differently cored OPTs to
find out what happens at extremes of F.

If I could measure flux inside the core...but I can't. I hoped it
might be easier to find a BH curve.

So GOSS will be around for awhile since there is little that can
replace it.

Phew.

cheers, Ian

Ian Iveson wrote:

"Patrick Turner" wrote

Curves and properties of GOSS is at a few websites if you search.

An example would be useful. I wouldn't have asked if I hadn't looked
already.

The basic facts about transformers might be found, but sure, you are
right,
not many give the nitty gritty details.
Maybe you'd find more in a university library.



Its not easy to understand all data you find.

The principles are nice and simple, but not so easy to model as an
electrical circuit. The main problem is finding detailed data
measured under stated conditions.

Better to compare measurements with differently cored OPTs to
find out what happens at extremes of F.

If I could measure flux inside the core...but I can't. I hoped it
might be easier to find a BH curve.

But at the end of the day, we need to know what the final
results are, so if the OPT has a low Fsat, low distortion, wide bw,
etc, then the steel must be OK.
Users want to know if the BH curves are good, or bad.
They will choose good over bad if the price is right.
Audio nutters like us who worry and fuss over OPT construction
are of no concern to large companies mainly making GOSS
for major mainstream electical engineering.
Most of them know how to make good iron for a mains tranny,
but as F rises the knowlege rolls off.

If you want to consider the BH curves from the purist's position,
surely you ned to at least understand how they are measured, signal
used,
circuit, CRO method, and so on.
The methods haven't changed much perhaps, and a search in a uni
library would be where I'd go if BH measurment and knowledge isn't
to be found on the web.

I am grateful to have learnt so much from days spent in university
archives in the cool basements of university buildings.


I haven't seen too much pure theoretical stuff on the web.
Tempel just have the details of the gear they sell and
a clearly expressed message :- "we make the best".
That's debatable of course.

So GOSS will be around for awhile since there is little that can
replace it.

Phew.

One could use cobalt cores. Bleedin expensive.
If GOSS were to vanish, amorphous would become common,
and cheaper, but whether it translates to better music is a moot point.

The bretheren at Lundahl wax lyrical about amorphous cores,
but offer not one syllable or graph explaining why
amorphous is better from the technical point of view.

Patrick Turner.



cheers, Ian

On Thu, 31 Mar 2005 10:56:07 GMT, "Ian Iveson" wrote:

Anyone got a complete DC B-H initial curve and loop for GOSS, or
link to same? I need scale and enough detail to extract data for
regression.

M4 or M2 would be best.

Suggestions as to the best function to fit to the initial curve
would be appreciated too. Ideally it should be continuous through
the origin, and be symmetrical in first and third quadrants,
asymptotic to B/H = µ0, and get close to the initial curve from the
origin. Wish I had paid more attention to statistical distributions
at school coz I suspect that's what is needed.

BTW, with reference to earlier contributions on core losses, I find
frequent reference to skin effect in windings, and its equivalent in
the magnetic circuit of the core, but I haven't found any data.

Also BTW, what are we going to do for transformers when everyone
else is using switched mode for everything? Will GOSS sheet become
hard to find? I gather for large transformers in power grids,
amorphous is being dumped on the "third world" because it is not
much good, so perhaps GOSS has a secure future there.

cheers, Ian

There's some good info on grain oriented steel at:
http://www.transformercore.com/technical.htm

On another page they give some technical data, and 2/3 of the way down the page they say
curves are available on request:
http://www.transformercore.com/CRGO.htm

I've noticed that the grades of steel better than M6 aren't readily available in the
states, but there seem to be a number of overseas suppliers.

On Thu, 31 Mar 2005 10:56:07 GMT, "Ian Iveson" wrote:

Anyone got a complete DC B-H initial curve and loop for GOSS, or
link to same? I need scale and enough detail to extract data for
regression.

M4 or M2 would be best.

Suggestions as to the best function to fit to the initial curve
would be appreciated too. Ideally it should be continuous through
the origin, and be symmetrical in first and third quadrants,
asymptotic to B/H = µ0, and get close to the initial curve from the
origin. Wish I had paid more attention to statistical distributions
at school coz I suspect that's what is needed.

BTW, with reference to earlier contributions on core losses, I find
frequent reference to skin effect in windings, and its equivalent in
the magnetic circuit of the core, but I haven't found any data.

Also BTW, what are we going to do for transformers when everyone
else is using switched mode for everything? Will GOSS sheet become
hard to find? I gather for large transformers in power grids,
amorphous is being dumped on the "third world" because it is not
much good, so perhaps GOSS has a secure future there.

cheers, Ian

ARMCO Steel was one of the early developers and suppliers of GOSS and they have been
bought by AK Steel. They supply grades as good as M2. See:
http://www.aksteel.com/markets_products/electrical.asp

They have some data you can download at:
http://www.aksteel.com/markets_produ...l_oriented.asp

but there are no curves. You may have to ask to get them.

"The Phantom" wrote

ARMCO Steel was one of the early developers and suppliers of GOSS
and they have been
bought by AK Steel. They supply grades as good as M2. See:
http://www.aksteel.com/markets_products/electrical.asp

They have some data you can download at:
http://www.aksteel.com/markets_produ...l_oriented.asp

but there are no curves. You may have to ask to get them.

Thanks for both, er, Phantom!

Loved the diagram of squashed coils, and the general enthusiasm of
the Indian site. I have e-mailed them asking for curves.

Interesting stuff, iron. A serendipitous phenomenon, like water.
Hence the iron age, I suppose.

Still struggling with the maths so no great rush. Seems I need a
hyperbolic cotangent but spice isn't keen.

cheers, Ian