"beat" in a RC filter circuit

Dear all,

In the attached circuit, I see that there is some "beat" in the filtered waveforms, e.g. the min and max tend to oscillate when simulating for 0.1 ms with a time step of 0.0000001 s. Running the same simulation with 10x more time steps (0.00000001 s) removes the "beat". Any ideas of where this artefact is coming from? Many thanks - Thomas

by thomas_R27
February 14, 2024

When the results of a simulation yield nonsense I have usually found that the results are changing too fast for the time step chosen. Try making the time step much shorter. Or you might learn a lot by making the frequency of V2 much lower and also trying a sine wave rather than square.

by Foxx
February 22, 2024

1 Answer

Answer by thomas_R27

Thanks Foxx - I guess the curve is interpolated between points and that gives strange plots when there are not enough points! Many thanks Tom

+1 vote
by thomas_R27
February 23, 2024

That's it. Circuit Lab simply calculates conditions at each time step point and draws in a straight line joining the points. Lotsa luck

by Foxx
February 23, 2024

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