#86 jacobian singular, virtual resistances

0.0.17
closed
nobody
None
5
2013-06-20
2012-10-07
Bernhard Kuemel
No

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

============================================================

Discussion

  • voltage doubler

     
    Attachments
  • Frans
    Frans
    2013-06-06

    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.

     
  • Frans
    Frans
    2013-06-06

    • status: open --> closed
    • Group: --> v1.0_(example)