Kicad simulation issues

Schematic Simulation (Ngspice)
1

Hi! I’m trying to use Kicad for some simulations but nothing comes out of the graph apart from the voltage sources, and I don’t know what I’m doing wrong. I tried installing the official footprints and didn’t work, and then I tried a folder with lots of footprints and still not working either. I’m trying to run a simple 555 circuit. I will paste the error I’m getting, it’s probably an easy fix but I’m total noob and don’t know where else to look. Cheers

Circuit: KiCad schematic
Error on line 7 :
u1 0 net-_c2-pad1_ net-_r3-pad2_ nc_01 net-_c1-pad1_ net-_c2-pad1_ net-_r1-pad2_ net-_r1-pad1_ ne555
Unable to find definition of model nc_01 - default assumed
unknown parameter (net) 
Background thread stopped with timeout = 0
Doing analysis at TEMP = 27,000000 and TNOM = 27,000000
Initial Transient Solution
--------------------------
Node                                   Voltage
----                                   -------
net-_r3-pad2_                                0
net-_c2-pad1_                                0
net-_r1-pad2_                                0
net-_r1-pad1_                                0
net-_c1-pad1_                                0
v1#branch                                    0
 Reference value :  1,99874e-01
No. of Data Rows : 1901
Warning - approaching max data size: current size = 1955,008 MB, limit =  445,664 MB
2

Did you assign a spice model for the 555?

1 Like
3

Please have a look at the introductory tutorial at http://ngspice.sourceforge.net/ngspice-eeschema.html

Eeschma simulation manual is at http://docs.kicad.org/5.1.4/en/eeschema/eeschema.html#simulator

There is some info on 555 simulation though not with KiCad/ngspice, but plain ngspice at https://sourceforge.net/p/ngspice/discussion/ngspice-tips/thread/d2048be2/

Btw footprints have nothing in common with simulation: For simulation you will need a circuit diagram with components (from the symbol library), and ngspice model libraries for the diode, transistor and IC components.

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4

I thought the footprint would include the info for the simulation! I understand it now, I managed to install ngspice on linux and now it seems to be working fine with the examples from this link. Still have to try it with the 555 but looks promising for now, as everything seems a bit clearer! Thanks a lot for the fast reply.

5

Hey, I’m continuing to follow the schematics tutorial on http://ngspice.sourceforge.net/ngspice-eeschema.html

Trying to do the 3rd one, the bipolar amplifier, but I get an error message “Error: there aren’t any circuits loaded.”

The tutorial is not very straight forward as how to create the file for the BC546 spice model or where it should be located, so I just created a text file with the parameters and saved it on the project folder. Don’t really know what to do, everything seems just the same as his circuit example… If I should open a new topic let me know, just didn’t want to spam too much. Cheers

EDIT: Copying the text model provided in the tutorial for BC546 doesn’t work, had to tweak the text structure and now it works fine.

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