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#86 jacobian singular, virtual resistances
The attached circuit simulates without warnings/errors. When I change the simulation time or component values I get warnings and errors:
C1=5u, Stop=90m: no errors
C1=5u, Stop=91m: warnings (virtual resistances)
C1=5u, Stop=92m: no errors
C1=5u, Stop=93m: warnings (virtual resistances)
C1=5u, Stop=94m: no errors
C1=5u, Stop=100m: warnings (virtual resistances)
C1=5u, Stop=300m: warnings (virtual resistances), error (jacobian singular)
C1=1u, Stop=90m: no errors
C1=1u, Stop=91m: warnings (virtual resistances)
C1=1u, Stop=92m: no errors
C1=1u, Stop=93m: no errors
C1=1u, Stop=94m: warnings (virtual resistances)
C1=1u, Stop=100m: warnings (virtual resistances), error (jacobian singular)
C1=1u, Stop=300m: warnings (virtual resistances), error (jacobian singular)
These things happen in other circuits as well. Are these bugs or my fault? How can I avoid them?
Thanks, Bernhard
Detail reports:
C1=5u, Stop=100m: warnings (virtual resistances)
Output:
-------
Starting new simulation on Sun 07. Oct 2012 at 15:35:06
creating netlist... done.
parsing netlist...
checking netlist...
netlist content
2 Diode instances
2 C instances
1 R instances
1 Vac instances
1 TR instances
creating netlist...
NOTIFY: TR1: average time-step 3.72162e-05, 446 rejections
NOTIFY: TR1: average NR-iterations 2.64198, 7 non-convergences
Simulation ended on Sun 07. Oct 2012 at 15:35:07
Ready.
Errors:
-------
WARNING: TR1: inserted virtual resistance at node `n2' connected to [C1,D2,D1]
WARNING: TR1: inserted virtual resistance at node `n2' connected to [C1,D2,D1]
========================================================
C1=1u, Stop=100m: warnings (virtual resistances), error (jacobian singular)
Output:
-------
Starting new simulation on Sun 07. Oct 2012 at 15:35:51
creating netlist... done.
parsing netlist...
checking netlist...
netlist content
2 Diode instances
2 C instances
1 R instances
1 Vac instances
1 TR instances
creating netlist...
Errors occurred during simulation on Sun 07. Oct 2012 at 15:35:51
Aborted.
Errors:
-------
WARNING: TR1: inserted virtual resistance at node `n2' connected to [C1,D2,D1]
WARNING: TR1: inserted virtual resistance at node `n2' connected to [C1,D2,D1]
WARNING: TR1: inserted virtual resistance at node `n2' connected to [C1,D2,D1]
ERROR: TR1: Jacobian singular at t = 4.165e-02, aborting transient analysis
============================================================
voltage doubler
This is a known issue, jacobian singulars do occur sometimes. Please try to play with the number of simulation points, and add resistances to floating nets.