topic Re: Spice Simulation not accepting models from directory. in Fusion Electronics Forum

Spice Simulation not accepting models from directory.

mjenkins5720 — Mon, 16 Nov 2020 23:36:44 GMT

Hello everyone,

I am trying to run a simulation with user model files. The simulation error says that the file should be in C:\Users\user\Documents\Fusion 360\spice. However even if i place then in that directory still gives error.

I have attached the spice model to the device in the library.

I would appreciate any help on the subject.

Re: Spice Simulation not accepting models from directory.

panpan_fan — Tue, 17 Nov 2020 07:42:59 GMT

Hi @mjenkins5720

I hope you are doing well!

It should work if the spice model is put in the path C:\Users\user\Documents\Fusion 360\spice

You can try to add the model again in the library and then add the part again.Or you can remove the model and add the model in the path again.

If it still can't work, please leave your comment, thanks!

Regards,

Panpan Fan

Re: Spice Simulation not accepting models from directory.

mjenkins5720 — Tue, 17 Nov 2020 11:08:00 GMT

Panpan Fan

I have tried, adding it to the old spice directory, the eagle examples directory, the Fusion 360 directory. It appears to have a problem at simulation time, not always at upload time. An additional note, the files are complex LM317HT adjustable voltage regulator.

Re: Spice Simulation not accepting models from directory.

panpan_fan — Tue, 17 Nov 2020 11:11:41 GMT

Hi @mjenkins5720

Thanks for your feedback!

Would do mind sending me your schematic file and all your mdl files? I will give you my email address as a private message. Then we can find the root cause more easily. Thanks!

Regards,

Panpan Fan

Re: Spice Simulation not accepting models from directory.

mjenkins5720 — Tue, 17 Nov 2020 22:03:47 GMT

Panpan Fan

Attached is what I think is the Electronics schematic, Also i attached the LM317 model, i had to change the extension to .txt so the post would accept it.

Please let me know if you make any progress.

Regards

Mike

Re: Spice Simulation not accepting models from directory.

edpataky — Wed, 18 Nov 2020 17:51:37 GMT

Mike, I downloaded the files above from Panpan, and ran your simulation to show what it looks like with a DC sweep of the input ... note that the schematic calls for a model called LM317HT but the model itself calls it LM317 ... they have to match, so i changed it to LM317 in both places ... i also added names to the various signals in the sch ... and since the potentiometer part requires a .PARAM statement, i added that as well

Re: Spice Simulation not accepting models from directory.

edpataky — Wed, 18 Nov 2020 17:50:37 GMT

This is the naming i was talking about:

The filename, the model name, and the actual model name in the file all should match up .. in your case the name had "HT" at the end (came from the filename) but the model itself did not have it, so that would not work ... i fixed as shown

Re: Spice Simulation not accepting models from directory.

edpataky — Wed, 18 Nov 2020 17:55:21 GMT

Notice also the .PARAM statement .. it is simply a text object, and inside it you write .PARAM on the first line, then you can have one or more lines with variable=value, where variable is the name of a variable you want accessible to models, and value is the value

In your case, this potentiometer model has two variables, and so you need to set those values

Here is the model you are using within that POT part:

********************************************

* Autodesk EAGLE - Spice Model File

* Date: 9/25/17

* Variable resistor PIN1 ---/\/\/\/\--- PIN2

* |

* PIN3

********************************************

.subckt POT 1 2 3

R1 1 3 {val*var/100}

R2 3 2 {val-val*var/100}

.ends POT

Re: Spice Simulation not accepting models from directory.

mjenkins5720 — Wed, 18 Nov 2020 22:34:14 GMT

Thank you for the response,

However I still have the problem with Fusion asking for the file in the directory, Even after i place the file in de required directory.

How did you add the model, In the part or in the schematic?

Re: Spice Simulation not accepting models from directory.

mjenkins5720 — Wed, 18 Nov 2020 22:37:30 GMT

Thank you for the reply,

I had wonder how the simulation would know what value to use in the pot.

Is this something I can add to the part, or does it have to be added to the schematic?+

regards

Mike

Re: Spice Simulation not accepting models from directory.

edpataky — Wed, 18 Nov 2020 22:55:44 GMT

>> I had wonder how the simulation would know what value to use in the pot.

see my above comment about the .PARAM statement .. there is explanation there

Re: Spice Simulation not accepting models from directory.

edpataky — Wed, 18 Nov 2020 22:56:55 GMT

>> However I still have the problem with Fusion asking for the file in the directory, Even after i place the file in de required directory. How did you add the model, In the part or in the schematic?

I added the model in the schematic, but note that i had to make sure the model was in the directory fusion tells you to put it in, and also see my explanation above about the filename and model names ... if the model name is not properly the same as the filename it will not find it

Re: Spice Simulation not accepting models from directory.

mjenkins5720 — Wed, 18 Nov 2020 23:09:38 GMT

Ok It finally accepted the LM317 model, However I misspelled the PARAM , and i cant seem to be able to edit it or delete it.

Can you please explain how.

Re: Spice Simulation not accepting models from directory.

mjenkins5720 — Wed, 18 Nov 2020 23:23:05 GMT

Also,

what layer do I need to place the text in.?

Re: Spice Simulation not accepting models from directory.

edpataky — Thu, 19 Nov 2020 04:06:15 GMT

just right click on it and choose properties and change the text

Re: Spice Simulation not accepting models from directory.

edpataky — Thu, 19 Nov 2020 04:07:15 GMT

You can place it in the info layer