In experimenting with the Qucs ideal library I found the Diff and Int functions didn’t work so I reconstructed schematics to debug them. The schematics didn’t work in Qucs or QucsStudio but do work in Qucs-S and LTSpice.
I realize the functions are not realistic and the data they produce is suspect but I was wondering why I couldn’t get QucsStudio to work regardless of the integration method I chose.
I only mention the issue because I put the identical circuit into Qucs-S, 5Spice and LTSpice and they ran the circuit. I realize the circuit is not a realistic one but I also tried the usual trick’s of adding series/parallel resistors and still couldn’t get it to run.
I do wonder why Qucs has 4 components in the Ideal Library that don’t work.