I’m fairly new to Qspice so don’t know if this is caused by some misconfiguration in my system, or bug. I pick a built in diode by typing “D” and place it on the schematic, connected to the parts for the rest of the design. I right click the diode and choose a model from the list it provides (ie: 1N914). I then run the simulation, and get the message:
"Didn’t find a model for “1N914” – defaults assumed.
Using the selection guide choice for Silicon Diode “1N4148” works, but others in the list, such as “1N4148A”, “1N914”, etc… do not. The Symbol Properties shows the library as “Diode.txt”. The only copy of that file on my computer is in “Program Files>QSPICE” and it does contain .models for 1N4148A, 1N914, etc… I also tried placing a Schottky diode from the built in parts and selecting “1N5817” using the Selection Guide. It also gives the warning about not finding the model. And the Schottky.txt file defined in the properties (also in Program Files>QSPICE) does in fact contain that model.
Has my system somehow lost the location of those libraries? That would be odd, since it seems to find them when I use the selection guide after right clicking the component. Just not when I run the simulation.
Any chance that somewhere in your schematic with a diode without picking a model?
In this schematic, I can get different I-V curve from default D, 1N914 and 1N5817.
If you delete D0 in this schematic, the warning should be removed.
Thanks for the reply. I just made a very simplistic schematic with just one voltage source, two diodes and two resistors and was able to set the diodes to 1N914 and 1N5817 and run the simulation with no warnings. I go to my large schematic where I have the issue and check. There are 4 diodes. If I set them to 1N4148, then no warnings. If I change one to 1N914 I get a warning.
I then start with a blank schematic and copy the other one to it. Same warning. Start deleting parts. The warning goes away when the diodes are the only remaining semiconductor (remove all transistors and ICs). Then another test: In a blank schematic I place four diodes and set them as 1N914. Then I copy/paste the main schematic into that otherwise blank one. I delete the diodes that were copied over and replace them with the 4 I had placed before the copy/paste. No warning on simulation. I then delete those 4 diodes and place 4 new ones, setting them as 1N914. Now I get 4 warnings. So if the diodes are placed first, no warnings. If placed last, then warnings.
Could one of my transistor or IC parts being placed first somehow mess with placing diodes afterward?
