Electrical – tina convergence issue

circuit analysisspicetexas instruments

I have created a circuit using TINA and it has given me a "convergence error". TINA is telling me the issue is LED1 however I am unable to troubleshoot the problem.

The circuit is as below:
enter image description here

Best Answer

A convergence error means you have positive feedback in your system and it 'goes to infinity' or your system is as such that it is hard to find the steady state conditions.

It looks like you need a ground.

Another way to combat convergence problems in simulations (not just tina) is to:
1) Introduce parasitic series resistance (kind of like a wire under 1 ohm usually)
2) Introduce parasitic parallel resistance (1e9 Ohms will help some nodes converge, and will have little effect on most circuits)
3) Parasitic capacitance to ground (1e-14 F will knock out some high frequency numerical errors that may cause the simulation to 'blow up')