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LTspice problem

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confounded

New Member
Hi, i have a problem with LTspice.

I just started to learn this by watching the two beginner videos. ECE Software & Training Videos
In the 2nd video it describes downloading a LTspice model from a manafacturer and using it in your schematic.

I downloaded the spicemodel of a BC847BPDW1T1_NPN transistor and saved it to a new folder i called 'LTspicemodels' in desktop.

ON Semiconductor (I downloaded the 1st file in this list)

The video says that to use the new component you right click on name of existing transistor you've placed and replace it with the name of the new component. I did this.

Then it says you add a spice directive by pressing 's' and then typing .include C:\etc
I typed in .include C:\Desktop\LTspicemodels\BC847BPDW1T1_NPN[1]

However when i go to run the sim i get the message: SPICE ERROR could not open include file ''C:\desktop\LTspice\BC847BPDW1T1_NPN[1]''

Please help

also how do i post my schematic so it can then be viewed by others?
 

ericgibbs

Well-Known Member
Most Helpful Member
Hi, i have a problem with LTspice.

I just started to learn this by watching the two beginner videos. ECE Software & Training Videos
In the 2nd video it describes downloading a LTspice model from a manafacturer and using it in your schematic.

I downloaded the spicemodel of a BC847BPDW1T1_NPN transistor and saved it to a new folder i called 'LTspicemodels' in desktop.

ON Semiconductor (I downloaded the 1st file in this list)

The video says that to use the new component you right click on name of existing transistor you've placed and replace it with the name of the new component. I did this.

Then it says you add a spice directive by pressing 's' and then typing .include C:\etc
I typed in .include C:\Desktop\LTspicemodels\BC847BPDW1T1_NPN[1]

However when i go to run the sim i get the message: SPICE ERROR could not open include file ''C:\desktop\LTspice\BC847BPDW1T1_NPN[1]''

Please help

also how do i post my schematic so it can then be viewed by others?
hi,
As a newcomer to LTS I'm still studying.
I have noticed in this example the name of the device differs from that within the lib description.

I have edited the lib file:
The text was. Qbc847bpdw1t1-npn, I changed this to: bc847bpdw1t1_npn
and resaved it as bc847bpdw1t1_npn.lib

I placed this lib file in my main LTC/LTspiceIV/lib that is located in the Program Files folder.

I then created a dummy *asc file, attached, see the name of the transistor and the include directive.

The asc file runs OK.

I'm sure there must be an easier way, if so, lets hear it from the pro's.:)

To attach a file to your posts use the 'manage attachments' button
 

Attachments

Last edited:

confounded

New Member
Thanks for replying,

I'm going to go try what you suggested now.

I meant how can i attach my LTspice model i made. I can't seem to find it when i browse in manage attachments. I go into the LTspice folder and the models i have made are not listed
 

confounded

New Member
I don't know much about computers, thank you for your patience

I opened the file you attached and replaced the name of my lib file with the one you have in your INCLUDE and i now get a different error message:

can't find definition of model ''BC847BPDW1T1_NPN'' select ok to continue the simulation with the default model or cancel to quit now.

I dont seem to be able to attach an asc file like you have to your reply
 
Last edited:

ericgibbs

Well-Known Member
Most Helpful Member
I don't know much about computers, thank you for your patience

I opened the file you attached and replaced the name of my lib file with the one you have in your INCLUDE and i now get a different error message:

can't find definition of model ''BC847BPDW1T1_NPN'' select ok to continue the simulation with the default model or cancel to quit now.

I dont seem to be able to attach an asc file like you have to your reply
hi,
To attach a file.

Use 'Reply to Thread'
Scroll down the page to 'manage attachments' button.
Click the button, a 'manage attachments' window should appear
Use the Browse option locate the *.asc file,
Click the 'upload' button
when uploaded click 'close this window'.

Give it a try.:)
 

confounded

New Member
I get to 'use the browse option to locate file' and i cant locate a asc file.
I go into where it is in the LTspice folder and i dont see any asc files :confused:

Actually i can only see the asc files when im in LTspice. Even looking in the LTspice folder via my computer/programfiles/ltspice etc i dont see the asc files
 
Last edited:

ericgibbs

Well-Known Member
Most Helpful Member
I get to 'use the browse option to locate file' and i cant locate a asc file.
I go into where it is in the LTspice folder and i dont see any asc files :confused:
hi,
If you use 'windows explorer' can you find any asc files in the LTSpice sub folders.????
 

confounded

New Member
Sorry but i'm such a noob with computers you must explain how i use windows explorer to look.

Is that just looking through my computer then into programs etc.

just edited my last post and you had replied already :)
 

ericgibbs

Well-Known Member
Most Helpful Member
Sorry but i'm such a noob with computers you must explain how i use windows explorer to look.

Is that just looking through my computer then into programs etc.

just edited my last post and you had replied already :)
no problem.

click Start [bottom left of desktop]
Programs/Accessories/Windows explorer

OK.
 

confounded

New Member
When i follow those instructions and click on windows explorer it opens up my documents folder.
When i explore into myprograms then into LTspice i dont see any asc folders. All i see is shown in attachment

I'm using Vista in case that helps
 

Attachments

ericgibbs

Well-Known Member
Most Helpful Member
When i follow those instructions and click on windows explorer it opens up my documents folder.
When i explore into myprograms then into LTspice i dont see any asc folders. All i see is shown in attachment

I'm using Vista in case that helps
In that image you have 3 'yellow' folders, click on the examples and open the folder
 

confounded

New Member
There are lots of asc files :) but my model i saved is not one of them :( Where can i find that?

Got to go out for a few hours now, thank you for your help and quick responses
 

Attachments

Last edited:

ericgibbs

Well-Known Member
Most Helpful Member
There are lots of asc files :) but my model i saved is not one of them :( Where can i find that?

Got to go out for a few hours now, thank you for your help and quick responses
OK.
Do this.
Click Start
Search
For Files or Folders
type in the name of the file into the search for text box
[make sure you have spelt the name correctly]
click Search.
 

confounded

New Member
Ok i had to do a scan that took the same amount of time as i took me to eat a large bowl of cereal but it found it :)

And then i dragged it to desktop and then uploaded it from there so success 1 :D

However my simulation still doesnt run and i still get the error message:

can't find definition of model ''BC847BPDW1T1_NPN'' select ok to continue the simulation with the default model or cancel to quit now.

Can anyone help please
 

Attachments

Last edited:

Torben

Well-Known Member
Hi there,

The model name you're using in your schematic should match the 'MODEL' string in the library file, not the name of the library file itself.

Right-click on your transistor's value and change it from BC847BPDW1T1_NPN to Qbc847bpdw1t1-npn and try it.

I got this by looking in the BC847BPDW1T1_NPN.lib file using a text editor:

Code:
**************************************
*      Model Generated by MODPEX     *
*Copyright(c) Symmetry Design Systems*
*         All Rights Reserved        *
*    UNPUBLISHED LICENSED SOFTWARE   *
*   Contains Proprietary Information *
*      Which is The Property of      *
*     SYMMETRY OR ITS LICENSORS      *
*Commercial Use or Resale Restricted *
*   by Symmetry License Agreement    *
**************************************
* Model generated on Feb 28, 00
* MODEL FORMAT: PSpice
.MODEL Qbc847bpdw1t1-npn npn
+IS=1.02883e-10 BF=3441.88 NF=1.5 VAF=50.4069
+IKF=0.0513316 ISE=6.57032e-12 NE=1.90684 BR=11.3392
+NR=1.5 VAR=2.18491 IKR=0.513316 ISC=1e-16
+NC=4 RB=0.117532 IRB=0.100021 RBM=0.100913
+RE=0.376664 RC=1.88332 XTB=50 XTI=4
+EG=1.05 CJE=9.22073e-12 VJE=0.680201 MJE=0.85
+TF=5.8626e-10 XTF=3.3324 VTF=7.33802 ITF=0.210664
+CJC=4.07024e-12 VJC=0.95 MJC=0.347426 XCJC=0.800007
+FC=0.114115 CJS=0 VJS=0.75 MJS=0.5
+TR=1e-07 PTF=0 KF=0 AF=1
Check out the line which starts with the word 'MODEL'. That tells you the model name to give to your transistor.

Also, if you save the .lib file to the sub/ directory inside lib/, (i.e. move it to C:\Program Files\LTC\LTspiceIV\lib\sub\BC847BPDW1T1_NPN.lib) then you can omit the directory from your .include line and just have the filename (i.e. '.include BC847BPDW1T1_NPN.lib') which is much shorter (and more portable, too).


Hope this helps,

Torben
 
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