What is wrong with my project simulation in Proteus?

Question

Electronics

Here is such a simple scheme.
Here are the errors he writes to me:

[SPICE] transient GMIN stepping at time=0.0199862
[SPICE] DELMIN increased to 3.46945e-018 due to lack of time precision
[SPICE] TRAN:  Timestep too small; timestep = 4.33681e-019: trouble with node #00002.

Using the method of scientific poke, we managed to find out that the problem lies in the red, using the RLY
- SPCO relay . 1 (winding 6-7, 3.5 V) , fig. 3 (winding 5-6, 2.5 V) , fig. 4. (winding 4-5, 7 V) Version Proteus Release 8.3 SP2 (19906) Exported project ----------------------- -------------------------------------------------- -------------------------------------------------- - Edit 1 Changes:

• Instead of transformers, I installed two sources of sinusoids, respectively, 7V, 2.5V, 3.5V.
  

Result:

• The errors are gone.
  
• Inappropriate voltage drop behavior. (Screen)
  

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Answer 1

This is Proteus. At the very same troubles fly out when simulating analog circuits.
Bypass option - set an analog analyzer (Graph Mode -> Analog), set measurement points, and simulate according to the schedule. At least it works more often.
You can try adding capacitances and resistors in the circuit (more realistic model), but this most likely will not help.