Hi Everyone, I’m new to Kicad, but familiar with spice simulators as i used Simterix for many years. Retired now but still keeping up my interest in circuit design and semiconductor modelling.
I have a problem with getting the integrated ngspice tool to display a curve family for a modelled device. It’s simply a DC sweep of anode voltage with steps in the grid bias of a valve (vacuum tube) model I’m developing. Using the simulation tool this is easily set up. but when run it I see each of the grid voltage steps plot then quickly replaced by the next step run, finally leaving only the last run visible. I need to see all step runs on the same graph.
I’ve searched through the doc and on internet but can’t find any info on this problem. Can anyone advise how this might be achieved in Kicad simulation?.
I run Spice once per 5 years for few days and then next 5 years don’t need it.
I am still in KiCad V7.
Few months ago were my those few days I tried Spice in KiCad for the first and last time.
I think KiCad Spice interface (in KiCad V7) is not very powerful.
I have seen info that in V8 there are some important improvements in it. But I would expect it being still in half a way. KiCad is mainly PCB design program and Spice is still only the added feature.
It is my few cents that may be let you have a more distance view at its state now.
Thanks for your reply Piotr, Yes, I think this is the issue. Kicad has been a very valuable tool for engineers in PCB design and layout but simulation is still the poor cousin.
It’s just frustrating that such a simple task as multiple runs over stepped parameter is not
implemented. It’s possible in ngspice but the graphic interface tool just doesn’t seem to support it.
As I mentioned in my post, I can see the plot for each run briefly appear then get over written by the next run, surely this could be a easy fix in software just don’t erase the last plot in multi-run sims.
Otherwise, the simulation tool is very accurate and useful.
If you think it is a bug then report it.
Or wait for 8.0.2 (I suppose will be soon) then check if the bug is still there and if so report it.
KiCad versions X.0.0 and X.0.1 typically have many bugs so there is nothing surprising to find a bug.
The higher the last digit the harder is to find a bug.
It happened few times to me to see reported by me bugs being fixed the next day.
In my first post I said: “I am still in KiCad V7”.
About V8 I only said: “But I would expect it being still in half a way.”
Can’t be more specific.
I was trying to share my general opinion and speculation with someone encountering difficulty in making more than basic use of Spice, being a part of program generally intended for something else.
So my suggestion to wait for 8.0.2 made perfect sense even I didn’t know that.