QUCS Studio to uSimmics transition: Custom part issue? eg BAR64

[sineclear]

Hello,

I’m a huge fan of uSimmics. Thankyou for the great work.

I ran across a problem with a simulation working in uSimmics v5.8. This was not seen for exact same circuit in QUCS Studio 4.3.1

I’ve narrowed problem down to import of custom part generated from pspice .cir file attached. I’ve attached a simple cutdown of the circuit “broken_use_BAR64.sch”. Rename diode file to attached custom .sch as necessary.

This example illustrates if you have both BAR64 enabled, the simulation is aborted. If you have a single BAR64, simulation will run.

In my full circuit I could not even have one BAR64 diode enabled,  otherwise simulation aborts. Warning message “Warning in ‘AC1’: Inserting 1 GOhm at node “xxx” because it’s floating.” is displayed in full circuit, but not cut down circuit attached here.

This is similar in nature to this thread: https://qucsstudio.de/forums/topic/harmonic-balance-simulation-fails/ This was resolved by opening up the transistor model properties and change Xcjc to 1.0

Information:

Starting “broken_use_BAR64.sch” on Tue 29. Apr 2025 at 14:26:50

 

creating netlist… done.

analysing circuit… done.

solving circuit… done.

saving result…

 

Errors occured after 4.743 sec

Aborted.

 

Attachments:

1. Duplicate_Custom_Part_Issue_BAR64.zip

[QucsStudio]

Hello,

many thanks for the bug report! I can reproduce it. I happens because inside the subcircuit (BAR64), the port nodes are labeled. Thus, the best work-around is to delete these labels. I will fix it in the next release.

[sineclear]

<p style=”text-align: left;”>Thankyou for work around. Much appreciated! Hope my small donation helps you continue this fantastic project.</p>

[QucsStudio]

Thanks for the donation! It definitely helps to keep the project alive.

[Author]

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