DC simulation crashes with some circuit #9
Comments
|
which version of Qucs are you using, the |
|
I am using the |
|
it could also be related to issue Qucs/qucs#710. To check the |
|
Here is the output of I think it answers to the question since the version is newer than 2.25. Do you need I try with the development version ? |
|
:( I wanted to get back to business using qucs and finishing the qucs workbook.... but .... it works also using a sweep parameter with a single point, constant.
|
|
As mentioned above, please check your system |
|
I got infinite loop on |
|
@devel0 , the netlist for your circuit is generated without problems here. Then the transient simulation is quite slow but this is unrelated. |
|
glad to hear it works for you, this mean that there are some dependencies different from mine. I tried DC simulation but that worked. what I'll try in short will to prepare a docker environment that let reproduce consistently any behaviour and as a bonus allow to run within different inside system ( my host is Ubuntu 18.04 ) but within docker I can build and run internally a 17.04 image. I'll let know results. |
|
um, very strange. I did not check recently but the first step after creating the netlist for a DC simulation (" |
|
with
while attaching vscode to
reached by followings principals:
in particular, apart it doesn't solve it, seems can't exit this loop due to saveCurrent not proceed toward time limit
As already said I'll try now compiling either in Ubuntu 17.04 and 18.04 through a docker container and I'll let know if it works |
|
the transient simulation is not very robust and can get stuck like you saw. Unfortunately a general solution is not straightforward. But the initial issue was described as "got infinite loop on |
|
no, it's the same, or in other words with or without |
|
On Fri, Oct 19, 2018 at 11:38:43PM -0700, in3otd wrote:
um, very strange. I did not check recently but the first step after
creating the netlist for a DC simulation ("`creating node list for DC
analysis`") should be almost identical to what's done for a transient
simulation.
there's a switch involved with switchtime set to 0ms
does the model evaluate differently in dc vs tran@0s?
some spice models behave weird during events, maybe the switch does that
too?
another idea: if a dc analysis does not converge, the "result" might
look plausible. usually, attempting a transient from such a solution
fails: the time derivatives don't work.
|
|
I already think of that I tried removing switches results doesn't change, |
|
On Sat, Oct 20, 2018 at 09:59:52AM -0700, in3otd wrote:
the transient simulation is not very robust and can get stuck like you
saw. Unfortunately a general solution is not straightforward.
I know it's cheating. your simulation works in gnucsator with the bjt
model from ngspice17. put a "load models/ngspice17/bjt.so" into your
gnucsator.rc...
(background: the gnucap builtin modelgen (pre-verilog-A) bjt model has
been superseded and discontinued when this mechanism was ready.)
the hand written models for spice are full of hacks and convergence
related tricks, which you don't want to mess with in either verilog-A or
modelgen. sometimes this helps, sometimes this produces wrong
results. ymmv.
But the initial issue was described as "got infinite loop on `creating
netlist`": was then the behavior different without enabling debug?
its a very plausible convergence issue. this kind of stuff happens if
you leave your collector floating...
|
|
I'm sorry I realized now that this was not the correct issue for reporting problem about transient BJT that is instead issue Qucs/qucs#41 ; btw I confirm that using different transistor model 2N3906 in place of a BC557B it works ; working sim circuit can be found here. More I'm about a newbie in electronics but real circuit measures a voltage of 3.02V at Vm instead of 2.64V. sch |
|
thank you for referencing Qucs/qucs#41. this looks related. FWIW: i get 0->3.58V Vav and 3.75->0V Vm (transition at 1e-4s), using BC557B. |
Dear Qucs mainteners,
DC simulation crashes with some circuit, for example this one:
When I made the simulation into text mode, I get a segmentation fault. this segmentation fault appears on Linux Mint 19 (based on Ubuntu 18.04) but not on Linux Mint 18 (based on Ubuntu 16.04).
The thing which is weird is when I add a sweep (even if no parameter is swept), the simulation works well:
.SW:SW1 Sim="DC1" Type="lin" Param="alpha" Start="0" Stop="1" Points="6"I can give you additional information if you need them.
The text was updated successfully, but these errors were encountered: