Re: Question regarding transformer core library uploaded in files
Quite right for sensible designs, but I once
found a tiny core with few turns that saturated with 60 mV RMS
at 1kHz applied. It was supposed to accept at least 1 V at
100Hz, preferably 2 V. Fools can be so very ingenious.
On 2025-05-24 20:18, Jim Wagner via
groups.io wrote:
Millivolt
signals or millivolt differences in larger signals. If only
millivolt signals, then forget about core nonlinearity!
Totally!
?
Jim
?
?
Yes , out of the 4 two values (MS and K) have difference
of 1% approx which is fine for me
But the other two values differ a lot?
For me , A = 10.184 and C = 0.3
But in the library file provided it is A = 11.875 and C =
0.001
Since I am dealing with millivolts , I want to be as much as
precise as possible here
--
Best wishes John Woodgate RAYLEIGH Essex OOO-Own Opinions Only
If something is true: * as far as we know - it's science *for
certain - it's mathematics *unquestionably - it's religion
|
Re: Question regarding transformer core library uploaded in files
I don't see that the voltage is relevant. What
matters is what those parameters mean. For instance, if A is
what is often called A_i, the inductance factor, that difference
is not very significant.? Just assume the lower value. But what
C is, I can't guess.
On 2025-05-24 19:51, Vendy via
groups.io wrote:
Yes , out of the 4 two values (MS and K) have difference of
1% approx which is fine for me
But the other two values differ a lot?
For me , A = 10.184 and C = 0.3
But in the library file provided it is A = 11.875 and C = 0.001
Since I am dealing with millivolts , I want to be as much as
precise as possible here
--
Best wishes John Woodgate RAYLEIGH Essex OOO-Own Opinions Only
If something is true: * as far as we know - it's science *for
certain - it's mathematics *unquestionably - it's religion
|
Re: Question regarding transformer core library uploaded in files
Millivolt signals or millivolt differences in larger signals. If only millivolt signals, then forget about core nonlinearity! Totally!
?
Jim
On 05/24/2025 11:51 AM PDT Vendy via groups.io <edhooruper@...> wrote:
?
?
Yes , out of the 4 two values (MS and K) have difference of 1% approx which is fine for me
But the other two values differ a lot?
For me , A = 10.184 and C = 0.3
But in the library file provided it is A = 11.875 and C = 0.001
Since I am dealing with millivolts , I want to be as much as precise as possible here
|
Re: Question regarding transformer core library uploaded in files
Yes , out of the 4 two values (MS and K) have difference of 1% approx which is fine for me
But the other two values differ a lot?
For me , A = 10.184 and C = 0.3
But in the library file provided it is A = 11.875 and C = 0.001
Since I am dealing with millivolts , I want to be as much as precise as possible here
|
Re: Question regarding transformer core library uploaded in files
If you really mean 'slightly', and
realistically that could be +/-10%, don't worry about it.
On 2025-05-24 19:25, edhooruper via
groups.io wrote:
Hi ,?
I found a core library file Transformers
in our group's file folder
In that specific file the core material I needed was T38 which
was inside the library file - epocs core
.MODEL T38 CORE (MS=359.767869K A=11.875703 C=1m K=8.195163)
*** Core MnZn Material
However I also wanted to know how these values inside the file
was calculated or derived ?
I tried using Jiles Atherton model from the B-H curve to get
these parameters but what I get is slightly different from the
above values
Maybe Александр
Бордодынов could answer me cause he is the one who
uploaded the files
It would be very helpful for me?
Best Regards,
--
Best wishes John Woodgate RAYLEIGH Essex OOO-Own Opinions Only
If something is true: * as far as we know - it's science *for
certain - it's mathematics *unquestionably - it's religion
|
Question regarding transformer core library uploaded in files
Hi ,? I found a core library file Transformers in our group's file folder In that specific file the core material I needed was T38 which was inside the library file - epocs core .MODEL T38 CORE (MS=359.767869K A=11.875703 C=1m K=8.195163) *** Core MnZn Material However I also wanted to know how these values inside the file was calculated or derived ? I tried using Jiles Atherton model from the B-H curve to get these parameters but what I get is slightly different from the above values Maybe Александр Бордодынов could answer me cause he is the one who uploaded the files It would be very helpful for me? Best Regards,
|
On 24/05/2025 01:14, Andy I via
groups.io wrote:
I also really struggled with the new icons, they look like?
a 1980s kids play toy.?
I think that is under your control.
It is. Settings > Operation > Toolbar Style: Default | Legacy
--
Regards,
Tony
|
On Fri, May 23, 2025 at 05:47 PM, Hawker wrote:
24.0.12 was not bad.
I had to move all my libraries and get use to that it now has user libraries, and if you add to the stock libraries as we did in 17.x and update will break them so you need to make a user library.
That's been happening for much longer than you were aware.? We have been saying for years that users need to keep their libraries separate.? Many users ignored that advice.? It's just that version 24 got serious about enforcing it in a way that is hard to ignore.
?
I also really struggled with the new icons, they look like? a 1980s kids play toy.?
I think that is under your control.
I also hated that if you open two simulations it opens them in two different windows and not the same as 17.x. However the work around is to drag your simulation into the same window.
I'm pretty sure that is a Windows? thing, not an LTspice thing.? But I am not sure how one controls it.? I have the same behavior on an old PC that still runs LTspice 17.0.x.? I don't remember when that changed for me, but it was several years ago.
?
24.1 is a major PITA and you will need to redo a lot of your models, and simulations to be compliant to the new standards.
I do not think there are "new" standards, so much as new fixes for old bugs.? ADI did a lot of cleaning up code where older versions may have been sloppy.
?
Andy
?
|
On Fri, May 23, 2025 at 05:42 PM, Hawker wrote:
The includes were normal includes to include other models. They worked just fine before the update.? Looks like the new version has issues if they are templates. Regression bug.
Sorry, what does that mean?? Why is a template unique?
?
The older version also understood + in model definitions as lot of semi conductors supply models that way. It's a standard way to define a model, so if LT no longer support that, well what a PITA. New one doesn't so regression feature.
I disagree.? I do not recall finding any vendor-supplied models that had random "+" characters scattered amongst the parameters.? Do you find random misplaced characters in the middle of vendor-supplied models?? As a general rule, I did not.? It is definitely not a "standard way to define a model"; it is bad syntax.
?
Of course there is the standard SPICE line-continuation character, but it does not appear in the middle of a line.? It should only be at the start of a line.? On the other hand, if a SPICE user downloaded a model and then manually flattened it into single lines by removing carriage-returns without also removing the continuation characters, they would have created this problem.? Do you know if that is what happened to your models?
?
But I really can't tell what happened.? You have not shown us what your 2N5457 model looks line.? You have only shown us the error message.? Depending on what the .MODEL looks like, this might be worthy of reporting to Analog Devices for them to consider and (perhaps) fix or enhance.? Perhaps previous versions of LTspice ignored extra "+" characters that should not have been there.? Was that the right thing for it to have done?? Hard to say.? Ignoring mistakes is not correct either.
I get I can fix this stuff, but I have thousands of simulations and models going back to LT V days, and having to edit every one to use it is a royal PITA.
How's that?? Do you have thousands of bad .MODEL commands?? Or do you have one (or two or three) bad .MODEL files that need to be fixed?
?
BTW, there was no LTspice version V.? It went from III to IV to XVII to 24.? Just FYI.
?
Andy
?
|
On 23/05/2025 23:42, Hawker via
groups.io wrote:
Ok thanx. Sounds like maybe I just need to go back to
24.0.12, where I was. It was getting old, updates have been
fairly painless (the update from 17 took some getting used to
though with moving my model locations and user libraries) and
let 24.1 simmer for a while longer.
?
The includes were normal includes to include other models.
They worked just fine before the update.? Looks like the new
version has issues if they are templates. Regression bug.
The older version also understood + in model definitions as
lot of semi conductors supply models that way. It's a standard
way to define a model, so if LT no longer support that, well
what a PITA. New one doesn't so regression feature.
I get I can fix this stuff, but I have thousands of simulations
and models going back to LT V days, and having to edit every one
to use it is a royal PITA.
Is there anything in 24.1.x that wold push me to move there? I
certainly had issues with 24.0.x and before with newer TI models
that ran really slow or could not run if there were two
instances of them running. That was mny main complaint. What is
improved in 24.1 to move me there?
I don't have time to come here constantly, or multiple times a
day, I got work to do, I just need my tools to work.
Sounds like I should just go back to 24.0.12, thanx for the link
to find it.
You won't have to edit every simulation if you change to 24.1.8.
Many of the issues that cause backwards compatibility have already
been resolved, but admittedly not all of them.
The previously mentioned issue with the 2N5457, was simply due to
careless editing. Previous versions may have been more forgiving,
but errors are errors. You can't blame the new version for that.
Plus points with 24.1.x are improved convergence with some dodgy
models and a noticeable improvement in speed in most analyses. There
are also some new features, but you're probably too busy to be
concerned about that.
--
Regards,
Tony
|
On Fri, May 23, 2025 at 11:57 AM, Christopher Paul wrote:
I’ve been trudging along happily with LTspice 17.1.14. I’m sure that the newer versions offer some improvements, but I’m leery of the incompatibilities and bugs that are being reported.
?
With this in mind, would anyone like to offer a suggestion regarding upgrading?
24.0.12 was not bad.
I had to move all my libraries and get use to that it now has user libraries, and if you add to the stock libraries as we did in 17.x and update will break them so you need to make a user library.
I also really struggled with the new icons, they look like? a 1980s kids play toy.?
I also hated that if you open two simulations it opens them in two different windows and not the same as 17.x. However the work around is to drag your simulation into the same window.
But other than that it worked better, faster and was nicer.
24.1 is a major PITA and you will need to redo a lot of your models, and simulations to be compliant to the new standards. So unless there is something you need it is a ton of work to move to it.
|
Ok thanx. Sounds like maybe I just need to go back to 24.0.12, where I was. It was getting old, updates have been fairly painless (the update from 17 took some getting used to though with moving my model locations and user libraries) and let 24.1 simmer for a while longer.
?
The includes were normal includes to include other models. They worked just fine before the update.? Looks like the new version has issues if they are templates. Regression bug.
The older version also understood + in model definitions as lot of semi conductors supply models that way. It's a standard way to define a model, so if LT no longer support that, well what a PITA. New one doesn't so regression feature.
I get I can fix this stuff, but I have thousands of simulations and models going back to LT V days, and having to edit every one to use it is a royal PITA.
Is there anything in 24.1.x that wold push me to move there? I certainly had issues with 24.0.x and before with newer TI models that ran really slow or could not run if there were two instances of them running. That was mny main complaint. What is improved in 24.1 to move me there?
I don't have time to come here constantly, or multiple times a day, I got work to do, I just need my tools to work.
Sounds like I should just go back to 24.0.12, thanx for the link to find it.
|
Back up your files before installing a newer version.
|
.MODEL 2N5457 NJF(VTO=-1.8 BETA=0.00135 LAMBDA=0.001 RD=35 RS=31.5 + CGS=2.25E-12 CGD=6E-12 KF=6.5E-17 AF=0.5 )
^^^^^^^^^ The problem is obviously the '+', not the 'LAMBDA' ( proportional font used? ) The '+' is the SPICE line continuation character. Somebody or something cleaned up new lines (DOS / Unix / UTF8 / UTF16 or text editor problem?). -marcel
|
AS long as 17.1.14? works for you, don't
bother to upgrade. You could install 24.1.8 as a trial, while
keeping 17.1.14, but is it worth the effort?
On 2025-05-23 16:57, Christopher Paul
via groups.io wrote:
I’ve
been trudging along happily with LTspice 17.1.14. I’m sure
that the newer versions offer some improvements, but I’m
leery of the incompatibilities and bugs that are being
reported.
?
With
this in mind, would anyone like to offer a suggestion
regarding upgrading?
?
On Thu, May 22, 2025 at 07:04 PM, Hawker
wrote:
Am I correct in assuming in 24.1 you
cannot have a .include to a model you are not using?
I have not tried that, but I greatly
doubt that you cannot do that.? It has never been a
restriction before (in LTspice or anywhere, as far as I
know).? IMHO it would serve no useful purpose to have such a
restriction.
Did you read that somewhere, that it was
not allowed?
C:\Users\{user}\Documents\LTspice\user.jft(1):
Syntax error (unexpected input).
.MODEL 2N5457 NJF(VTO=-1.8 BETA=0.00135 LAMBDA=0.001
RD=35 RS=31.5 + CGS=2.25E-12 CGD=6E-12 KF=6.5E-17 AF=0.5
)
? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?
? ? ? ? ? ? ? ? ? ? ? ? ? ? ?? ? ? ? ? ? ? ? ? ? ? ? ? ?
? ? ? ? ? ? ? ? ?? ^^^^^^^^^
Was there more to that error message than
that?? Usually error messages have more information.
Could it be the stray plus sign between
the RS and CGS parameters?? If you see a floating
misplaced plus sign in your user.jft, try editing it out.?
If it is a 2-line .MODEL statement, that could be an
important clue.
OTOH, there were problems with many
(most?) of the JFET models that came in LTspice's
standard.jft, for several years.? They may have finally
whipped them into shape.
--
Best wishes John Woodgate RAYLEIGH Essex OOO-Own Opinions Only
If something is true: * as far as we know - it's science *for
certain - it's mathematics *unquestionably - it's religion
|
I’ve been trudging along happily with LTspice 17.1.14. I’m sure that the newer versions offer some improvements, but I’m leery of the incompatibilities and bugs that are being reported. ? With this in mind, would anyone like to offer a suggestion regarding upgrading?
toggle quoted message
Show quoted text
From: [email protected] <[email protected]> On Behalf Of Andy I via groups.io
Sent: Thursday, May 22, 2025 7:30 PM
To: [email protected]
Subject: Re: [LTspice] 24.1,x update woes? On Thu, May 22, 2025 at 07:04 PM, Hawker wrote: Am I correct in assuming in 24.1 you cannot have a .include to a model you are not using?
I have not tried that, but I greatly doubt that you cannot do that.? It has never been a restriction before (in LTspice or anywhere, as far as I know).? IMHO it would serve no useful purpose to have such a restriction. Did you read that somewhere, that it was not allowed? C:\Users\{user}\Documents\LTspice\user.jft(1): Syntax error (unexpected input).
.MODEL 2N5457 NJF(VTO=-1.8 BETA=0.00135 LAMBDA=0.001 RD=35 RS=31.5 + CGS=2.25E-12 CGD=6E-12 KF=6.5E-17 AF=0.5 )
? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?? ^^^^^^^^^
Was there more to that error message than that?? Usually error messages have more information. Could it be the stray plus sign between the RS and CGS parameters?? If you see a floating misplaced plus sign in your user.jft, try editing it out.? If it is a 2-line .MODEL statement, that could be an important clue. OTOH, there were problems with many (most?) of the JFET models that came in LTspice's standard.jft, for several years.? They may have finally whipped them into shape.
|
Re: Modelling magnetic core of EP10 with T38 material of TDK micronoas
I wrote:
Not everyone uses the same turns.
That should be "terms", not "turns".
?
Andy
|
Re: Modelling magnetic core of EP10 with T38 material of TDK micronoas
On Fri, May 23, 2025 at 10:55 AM, <edhooruper@...> wrote:
Is it possible to model a ferrite magnetic core in Ltspice ?
LTspice does not have a built-in magnetics modeler.? You need to turn to another program (such as the previously recommended FEMM) for that.? Once you get the circuit parameters, then you can use them in LTspice to simulate the circuit.
?
As you read in LTspice's Help, it does include some tools in the form of the Chan model for nonlinear magnetics.? They might include some of the model parameters you are trying to use, such as the cross-sectional area for which LTspice has a parameter also named "A".? But note that there are MANY parameters with similar names, such as "A" (or A-sub-something) and you need to fully understand which parameters you are dealing with in each situation.? Not everyone uses the same turns terms.? Most inductor modelers are familiar with AL, usually written as A-sub-L.? It is not the same as the A in the Chan model, nor the a, Ac, Ap, At, Aw, Aw(B), Aw(I), Awp, Aws, or A-T in the book you referred to.? Interestingly, the book apparently also uses a parameter named A (which you quoted in your reply), yet it does not list it in its table of Symbols.? What does that suggest?
?
Andy
?
?
|
Re: Modelling magnetic core of EP10 with T38 material of TDK micronoas
I also hve the circuit in Ltspice ,?
Is it possible to model a ferrite magnetic core in Ltspice ? Is there something similar pspice model editor for Ltspice ?
|
Re: Modelling magnetic core of EP10 with T38 material of TDK micronoas
On 23/05/2025 16:35, edhooruper via
groups.io wrote:
So I am modelling
the magnetic core in Pspice model editor
I got the B-H curve values from the TDK mcironas ferrite design
magnetic tool and uploaded that into pspice model editor
I also referred to the
for modelling the magnetic core
The values mentioned in the book matches with the ?
But the issue is the Pspice model editor uses Jiles Atherton model
to calculate the parameters Ms , A , C and K
When I give the B-H curve values into the Pspice model editor ,
the model editor internally somehow calculates the above mentioned
parameters which is way too far away from the ones mentioned in
the book (there is no values of MS , A , C and K mentioned in the
datasheet)
And when I give the parameters from the book into the Pspice model
editor , the curve does not fit and I am not getting the expected
results
Any idea on how to resolve this ?
Below table shows both the book values (2nd column) and spice
model editor values (3rd column)
|
Parameters
|
Values
from the book (MS is calculated)
|
?Values extracted
from curve by Pspice
Model
|
|
MS
|
342110
|
360595.7907737
|
|
A
|
1.26
|
10.185
|
|
C
|
2.60
|
0.39337
|
|
K
|
4.194e3
|
8.246
|
Please note, this group's purpose is to support LTspice, please
don't expect PSpice support.
--
Regards,
Tony
|
John Woodgate
Tony Casey