[Qucs-help] Re: Qucs - question

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

Am Di, 18.04.2006, 16:46, schrieb Ludek M:

> Hi,

Hello!

> please sorry my english.
> I make few schematic and it sometime not simulate. Progressbar into
> simulate
> window (file 1.dialog.jpg) not move (cpu 100% memory load grow, using
> swap).
> I testing schema with less component and I found two schema ( file
> tut3.sch). First is not function, second is function ok (opposite I
> allways cut).
> Have I any mistake in schema ? I tested more
> schemas, sometimes it funkcion, sometimes not.
> I have ver 0.0.8-1.i586 for Suse 10.0, HW -  proc 2,8GHz , mem 1GB. I
> tested before 0.0.7 ant it is same

Erm.  Yes.  In both schematics you have two sources (isource and vsource)
in series.  I wondered why this worked with the second at all...

Just a simple consideration:  the voltage-source forces 12V amp at 5k Ohm
resistor -> I = V/R = 2.4mA.  At the same time you force 1mA by the
isource... So this is a physical contradiction.

Same goes for the first one.

So my suggestion:

  1. Leave the current sources.
  2. Put somewhere a ground symbol where you want to have zero volt!

Hope this helps,
  Stefan.