Forums » CircuitLab Feature Requests

Suppose you have a very long simulation but you only want to see the last little bit.

For example a 500kHz switched mode supply where you want to see the last couple of switching cycles after it has settled over a couple of hundred ms.

It would be very useful to be able to only start plotting the output waveforms after a user defined delay after the start of the simulation.

It massively reduces data storage and removes the very long time taken to zoom into a tiny part of a huge data set. It can slightly reduce simulation time too because the plot data doesn't have to be dealt with until the plot start time.

Another example, you're simulating a 6AS7 vacuum tube, as a 10MHz oscillator. You want to see the waveform, but the dang tube takes about 30 seconds to warm up. Delayed plot start is very useful in this case.

Here's another example:

It only makes sense to look at the last 50ms or so of this plot but you have to wait for the whole 10s to run. I've cut the Step Time down to 1ms to make it run in a realsitic time but in fact it really needs to be 100us or less which then starts taking 10's of minutes to run.

And then you have to manually zoom in on the last few cycles which also takes a very long time ...

Well done CL!

From around the first week in June, it has been possible to start simulations at T > 0.

That is a big plus for running any sim where the interesting stuff only happens after a lot of settling time. Things like looking at the transient response of an SMPS to a load current step that can only be seen properly if it is applied after the SMPS has reached a post-startup steady state.