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Hi

My circuit here has a problem:

The time simulation works perfectly when only one horizontal switch wire is placed but when any more are added the simulator just gives an error.

I do not know if it's specific to these switches or if anything else on the circuit.

Simple problem - the lower three copies of the top circuit are all missing the horizontal wire connecting the switches to the resistor. Floating nodes usually result in simulation failure.

No that circuit works. It's those horizontal wires that cause the problem. each one of those lines can take a horizontal wire so long as no other one has it.

It also works if none of them have the horizontal wire.

Hi @Foamy, thanks for posting this. It does indeed seem to cause problems for the simulator. We're looking into it right now. It's hard for me to explain where the problem comes from, but here's another simpler circuit which "looks okay" in a vague sense, but causes a similar simulator problem:

If you stare at the above circuit a bit, you may think that it should simulate. All of the node voltages are well-defined. However, the current going around the loop is completely arbitrary -- these ideal voltage sources work just the same whether they're handling 0 current, or 10mA, or 10GA. That arbitrariness means that the solver can't come up with a solution. We've "overconstrained" certain variables (such as V(NODE1) and V(NODE2), both of which would be zero even if V2 didn't exist). And this means that as an inevitable mathematical result, we've underconstrained other variables, namely the loop current.

I'll post again when we've had the chance to dig in to the switches a bit more.

Hi all, we've just deployed new code that should fix this. @Foamy's circuit, with all of the horizontal wires connected, now successfully performs a DC solve -- it no longer gives the "Unable to get solution" message. Thanks for reporting this!

That was fast! Thanks.