Re: [Qucs-help] transient simulation problems

[Stefan J. <st...@gr...>]

On Do, 16.02.2006, 11:45, Stefan Böttner wrote:

Hi!

> Here it is.
>>
>>> when trying to do a transient simulation I keep getting the error:
>>>
>>> ERROR: TR1: Jacobian singular at t = <some small number here>,
>>> aborting transient analysis
>>>
>>> Before the error message I keep getting a lot of warnings such as:
>>>
>>> WARNING: TR1: inserted virtual resistance at node `_net3' connected
>>> to [T4,V1]
>>>
>>> What may be causing this?
>>
>> That is about a singular MNA matrix (a circuit with no or multiple
>> solutions) causing these error messages.  Can you send me the
>> schematic
>> so I can have a look and tell you about...

You can either e.g. set Vaf of T6/T7 to an appropriate value (i tried 10V
for both) or put an initial node voltage to the foo node (double click foo
label and enter 12 in the More... field).

Hope this helps, Stefan.