Re: What's the meaning of "**" ?
"a**b" means a raised to the power (or exponent) b.
?
"a^b" does?not mean the same thing, but with one exception.
?
IIRC, "**" is from the days of FORTRAN, or earlier.
?
Andy
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Re: What's the meaning of "**" ?
On 21/03/2025 18:01, pilou via
groups.io wrote:
in some models
I found some double "*": what's the meaning of this operator ?
"**" is the exponentiation operator.
See, e.g.: Help > LTspice > LTspice? > Circuit Elements
>B. Arbitrary Behavioral Voltage or Current Sources > The following functions table (near the bottom).
--
Regards,
Tony
|
What's the meaning of "**" ?
Hello,
in some models I found some double "*": what's the meaning of this operator ?
Thanks a lot in advance.
|
Re: Four switch non inverting buck boost converter not converging
On 21/03/2025 16:14, hetals via
groups.io wrote:
LT spice is showing issue with random nodes in the simulation
anytime I change settings or add some resistance or make any
change. I have attached the link for simulation file too.??
?
For example, Convergence Failure: ?Time step too small; time
= 1.43435e-08, timestep = 1.25e-19: trouble with instance s1
There are a number of obvious things wrong:
- The left-hand pair of gate drive signals are complementary,
but have no dead zone, so both devices will conduct at
transitions.
- The right-hand pair are identical, so both devices are on ~22%
of the time and will short out the supply rail.
So firstly, remove the transistors and fix the gate drive waveforms.
Then try adding the transistors.
--
Regards,
Tony
|
Re: Four switch non inverting buck boost converter not converging
On Fri, Mar 21, 2025 at 11:14 AM, <hetals@...> wrote:
LT spice is showing issue with random nodes in the simulation anytime I change settings or add some resistance or make any change.
Those errors suggest that you made sloppy mistakes.? I don't know what settings you changed, but they should not have caused any errors about random nodes.? Adding resistors also would not cause an error like that, unless you did not connect to the parts.? I think you need to pay more attention to how you drew your schematic.
?
What settings did you change?? Where did you try to add resistors?? Can you upload your schematic that failed with those errors?
?
It should not be necessary to change anything inside the encrypted LTspice model.? It models just the MOSFETs.? Think of them as if they are "black boxes".
?
Please do not upload things that are not needed for the simulation.? The extra transistor symbols and the PDF file should not have been uploaded.
?
Andy
?
|
Re: Four switch non inverting buck boost converter not converging
On Fri, Mar 21, 2025 at 10:19 AM, <hetals@...> wrote:
I am trying to simulate Four switch non inverting buck boost converter with two different genesic switches G3R60MT07J and G3R75MT12J.
You are mistaken.? There is only one kind of switching transistor in the schematic, the G3R60MT07J.? If you meant for some of them to be G3R75MT12J, you forgot to add them to your schematic.
?
Andy
?
|
Re: Four switch non inverting buck boost converter not converging
I wonder if the 10 ohm resistor is not the load.? Maybe the converter's output load is R3, the 0.09669 ohm resistor in series with the choke, between the two sets of switching transistors.
?
Those two "1pf" resistors, R8 and R9, look badly misplaced.? That begs the question, "WTF"?? What were you thinking?? Obviously they are not 1 picofarad capacitors, but they are 1 picoohm resistors, which are about as close to short-circuits as you can get!
?
This circuit makes no sense as it is drawn.? There is little wonder there were problems trying to simulate it.
?
Andy
?
|
Re: Four switch non inverting buck boost converter not converging
On 21/03/2025 16:14, hetals via
groups.io wrote:
LT spice is showing issue with random nodes in the simulation
anytime I change settings or add some resistance or make any
change. I have attached the link for simulation file too.??
?
For example, Convergence Failure: ?Time step too small; time
= 1.43435e-08, timestep = 1.25e-19: trouble with instance s1
?
?
One tip for the future: put all models and symbols in the same
folder as the schematic. The schematic can't be open properly
without copying the symbol L3_GeneSiC_MTseries_TO-263-7.asy into the
top level directory. Also, don't use an absolute path for the
models, because it only exists on your PC.
--
Regards,
Tony
|
Re: Four switch non inverting buck boost converter not converging
Your schematic shows the 350V source connected
through 0.1 ohm to the 10 ohm load. That can't be right.
On 2025-03-21 15:14, hetals via
groups.io wrote:
Hi,
?
LT spice is showing issue with random nodes in the simulation
anytime I change settings or add some resistance or make any
change. I have attached the link for simulation file too.??
?
For example, Convergence Failure: ?Time step too small; time
= 1.43435e-08, timestep = 1.25e-19: trouble with instance s1
?
?
?
?
Best regards
Hetal?
--
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: Four switch non inverting buck boost converter not converging
Hi,
?
LT spice is showing issue with random nodes in the simulation anytime I change settings or add some resistance or make any change. I have attached the link for simulation file too.??
?
For example, Convergence Failure: ?Time step too small; time = 1.43435e-08, timestep = 1.25e-19: trouble with instance s1
?
?
?
?
Best regards
Hetal?
|
Re: Four switch non inverting buck boost converter not converging
On 21/03/2025 15:19, hetals via
groups.io wrote:
I am trying to
simulate Four switch non inverting buck boost converter with two
different genesic switches G3R60MT07J and G3R75MT12J. The library
files are encrypted, so I cannot make any changes there. I
have tried various methods like increasing time step and
tolerances, skipping initial operating point solution etc. but
nothing is working for me. Any suggestions regarding how to
resolve this issue?
What exactly is going wrong? What is the error message? If you want
informed suggestions, you will probably have to upload your
schematic with all models and symbols in a zip to Files > Temp.
In the meantime, are you sure the models are encrypted for LTspice
and not some other simulator, like PSpice? If it's encrypted for
one, it won't work in another.
--
Regards,
Tony
|
Four switch non inverting buck boost converter not converging
Hello everyone,
?
I am trying to simulate Four switch non inverting buck boost converter with two different genesic switches G3R60MT07J and G3R75MT12J. The library files are encrypted, so I cannot make any changes there. I have tried various methods like increasing time step and tolerances, skipping initial operating point solution etc. but nothing is working for me. Any suggestions regarding how to resolve this issue?
|
Re: PTC model with internal temperature rise
Hello everybody,
I would like to reopen this topic.
Indeed,?I compiled all of PTC models originally publied by John Popelish into one single library.
Moreover, I added one input pin compared to original model to be able to connect a voltage source where 1V reprensents 1°C.
Goal is to be able to "link" the PTC to another component that produce heat, for example a transistor case.
There are some "Junction-Case Dynamic Thermal Model" for that, you can refer to Tony Casey's "Example Schematic Illustrating Use Of MOSFET Thermal Model".
Please, find an archive into the temp files/temp section:
/g/LTspice/files/Temp/ptc_sh.zip
Thanks a lot,
Pascal
|
It's not good to add any files to LTspice's
own files. Keep them in the same folder as your .ASC file. You
can also make your own library file,
such as MySpiceFiles, and put your? .ASC and .SUB files in it.
On 2025-03-20 18:23, andrea.patuelli
via groups.io wrote:
I learned that
usually I need ?a .sub and .asy file to put in Sym and Sub folder.
--
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
|
On Thu, Mar 20, 2025 at 02:23 PM, <andrea.patuelli@...> wrote:
Hi Andy, hi John, thanks for your time .
My ask was only for find two model with the same graphic symbol, the same electrical comportament, and the same kind of installation.
As you might know already, the schematic symbol is not part of the SPICE model, and it has no real meaning.? You can draw and modify the symbols without changing the results of the simulation.? Let me emphasize again, that you can draw those symbols yourself.
I'm a newbie and sometime i find .lib, .sub, .model , .asy, .test, ecc. and is not easy to understand what i need for import a good model.
LTspice just needs a SPICE model for the component.? The filename's extension (.lib, .sub, .mod, .model, .txt, etc.) does not make any difference.? It just needs to be a SPICE model inside the file.
?
The schematic symbol is a .asy file.? You can create one yourself, or you can borrow one from another component that is similar.
?
Another trouble on my way is that I found an common author (Roberto Scaramuzzino) for both on this site, but give me an error about "missing loading lib UniversalOpamps2".
There are many mistakes that could have caused that error.? It might be simple.? Without seeing your files (the .asc schematic file, and all .asy symbol and model files), we can only guess what the problem might be.? If the schematic attempted to load the library file "UniversalOpamp2.lib" but looked like this:
? ? .lib UniversalOpamp2
then the problem was using the wrong filename.? "UniversalOpamp2" is not the same filename as "UniversalOpamp2.lib".
?
I cecked on web and It seams a problem of release in use (my release is 17.1.9)
Probably not.? But do not believe most things you find on the web.? They are often wrong.
Here my scheme:
As you know, pictures of your schematics do not help anyone.? If you want assistance with your schematics, you must upload the schematic file itself plus all symbol files and all SPICE model files that did not come with LTspice itself.? But do not include the .RAW or .LOG files!? Zip the needed files into one .ZIP file, then upload that .ZIP file to the Temp folder under Files.? Then write another message telling us that you did it.
?
Andy
?
|
Hi Andy, hi John, thanks for your time .
My ask was only for find two model with the same graphic symbol, the same electrical comportament, and the same kind of installation.
I'm a newbie and sometime i find .lib, .sub, .model , .asy, .test, ecc. and is not easy to understand what i need for import a good model. I learned that usually I need ?a .sub and .asy file to put in Sym and Sub folder.
Another trouble on my way is that I found an common author (Roberto Scaramuzzino) for both on this site, but give me an error about "missing loading lib UniversalOpamps2". I cecked on web and It seams a problem of release in use (my release is 17.1.9)
I'm building a Dual rail power supply , and loading two models (317-337) founds on this site, ?I read different Volts output values at the same point LM317-LM337 (24,4V-25,4V), putting the same input voltage but with sign different (+35V,-35V).
So I can understand that is not a easy work for a newbee? but I want learn from the best ;-)
?
Here my scheme:
?
Many thanks
Andrea
|
Re: Compiling and publishing other group's member modified models
On 20/03/2025 09:00, pilou via
groups.io wrote:
Hello John and Tony,
thanks a lot for your replies :)
Sorry, Indeed I'm french, nobody is perfect ah ah ah :D
Indeed, I wrote as we would write in french.
I wanted to mean "a member belonging to this group". So I
guess that the correct form would have been "group member".
The member is John Popelish and it seems that he didn't came
here since 2014.
Thanks a lot in advance and again sorry for my mistakes :)
John Popelish is no longer a member of this group. My guess is that
he no longer walks among us, but that is just a guess.
Tracking members' activity has become more difficult since this
group moved from the Yahoo! platform to groups.io. While still here,
old messages were renumbered so most of the old message links don't
work. In addition, many members had to re-apply to join the group,
so they were not automatically transferred over to groups.io, so the
records say I joined in 2018, but actually it was sometime before
2010 - I can't remember when.
--
Regards,
Tony
|
Hi, Andy. Language problem. Andrea means
'manufacturer', not 'individual'.
On 2025-03-20 01:42, Andy I via
groups.io wrote:
it's a lot of time that a looking for a a model ltspice
lm317 and lm337 made by the same hand.
Please tell us - why does it matter to you which individual person
created a SPICE model?
--
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: Compiling and publishing other group's member modified models
|
Re: Compiling and publishing other group's member modified models
Hello John and Tony,
thanks a lot for your replies :)
Sorry, Indeed I'm french, nobody is perfect ah ah ah :D
Indeed, I wrote as we would write in french.
I wanted to mean "a member belonging to this group". So I guess that the correct form would have been "group member".
The member is John Popelish and it seems that he didn't came here since 2014.
Thanks a lot in advance and again sorry for my mistakes :)
|
Tony Casey
John Woodgate