EveryCircuit simulator glitch

[tobia]

Playing around with the free version of EveryCircuit, I stumbled across some rather unusual behaviour.

Take their Diode example, change the voltage source to an AC source (select it, then wrench button on the bottom toolbar, then ~ button), raise it to 1MV peak and raise the resistor accordingly to 5Mohm. Then plot the input voltage (select the piece of wire between voltage source and diode, then click on the eye button on the bottom toolbar), plot the current across the diode, and the voltage between diode and resistor.

I expected to see either a traditional diode result, like the one you get with 1kV and 5kohm (see first picture) where the voltage drop is so tiny that it cannot be seen, or some kind of negative voltage breakdown.

I certainly did not expect what I got (see second picture.) The positive voltages look all right (1), but there's some funny stuff going on at negative voltage (2) with some 100kV of voltage and 50mA of current across the resistor and both seem to be leading the input voltage by 90°. That doesn't make any sense to me. And then there is a spike in current (3) at the beginning of the positive voltage cycle.

All in all, I'm inclined to file this whole "app" as a piece of trash, aka. some fancy GUI trying to hide the underlying simulator's limits. But I'm a newbie, so I'd like to get some better opinion on what is going on.

[T3sl4co1l]

Those results look pretty good, honestly.

You should expect the diode has some reverse capacitance.  The spike seems to be on the wrong side, suggesting a poor model (it's not transitioning smoothly from "low conductance" to "high conductance"?), but it also handles it well (it recovers quickly, and doesn't oscillate between values after the spike).

It's only a computational simulator.  Expecting realistic results from a computational model reflects poorly on the one doing the modelling, not the computer.

Tim