Simulation Aborted

Schematic Simulation (Ngspice)
1

Application: x86_64 on x86_64

Version: 8.0.0, release build

Libraries:
wxWidgets 3.2.4
FreeType 2.13.2
HarfBuzz 8.2.0
FontConfig 2.14.2
libcurl/8.4.0 (SecureTransport) LibreSSL/3.3.6 zlib/1.2.11 nghttp2/1.45.1

Platform: macOS Monterey Version 12.7.3 (Build 21H1015), 64 bit, Little endian, wxMac

Build Info:
Date: Feb 23 2024 15:23:55
wxWidgets: 3.2.4 (wchar_t,wx containers)
Boost: 1.82.0
OCC: 7.7.2
Curl: 7.87.0
ngspice: 42
Compiler: Clang 14.0.3 with C++ ABI 1002

Apart from crashing occasionally, I had a simulation working for a short time. But now it doesn’t and outputs this:

Note: Compatibility modes selected: ps lt a
Circuit: KiCad schematic
Doing analysis at TEMP = 27.000000 and TNOM = 27.000000
Using transient initial conditions
Warning: singular matrix: check nodes xu1.xu1b.x1.xu3.7 and xu1.xu1b.x1.xu4.8
Warning: singular matrix: check nodes xu1.xu1b.x1.xu3.7 and xu1.xu1b.x1.xu4.8
Warning: singular matrix: check nodes xu1.xu1b.x1.xu3.7 and xu1.xu1b.x1.xu4.8
Warning: singular matrix: check nodes xu1.xu1b.x1.xu3.7 and xu1.xu1b.x1.xu4.8
Warning: singular matrix: check nodes xu1.xu1b.x1.xu3.7 and xu1.xu1b.x1.xu4.8
Warning: singular matrix: check nodes xu1.xu1b.x1.xu3.7 and xu1.xu1b.x1.xu4.8
doAnalyses: TRAN: Timestep too small; time = 1e-16, timestep = 1.25e-17: trouble with xu1:xu1a.x1.xd4:idiode-instance d.xu1.d.xu1a.x1.xd4.d1
run simulation(s) aborted

Sometimes it says it can’t find a .DLL file, but I’m using macOS.

Anyway, I’m stuck and need some guidance. Any offers?

2

No offer without complete project (circuit plus all external models used).

1 Like
5

Thank you Holger. Complete project here:
Sim_acdc.zip (280.7 KB)

6

Thanks for the project.

I got it up and running by adding the line .options rshunt=1G into a text box of the Eeschema canvas. There is some model incompatibility which might need further investigation.

To obtain a stable output, the simulation time has to be 1 s or so. Thus I have raised TSTEP to 20u to spped it up at least a little.

1 Like
7

Thank you Holgar. For me to begin understanding the many command directives, I would need some kind of a a graph showing what “Time step”, etc. actually does. Your videos are very good for getting started, so I hope to watch future editions focused on commands.

Meanwhile, please can you show me how to simulate a repeating tone burst. Something like a repeating sequence of a 1kHz sine wave for 300ms followed by 500ms of silence. This is the kind of thing my hardware function generator does with ease.

8

Any suggestion how to achieve this?

9

Here’s another simulation I can’t get working.
Sim_k-filter.zip (56.1 KB)