I've been trying to sim a simple cap-multiplier circuit. It's a somewhat inaccurate model (my source is just a sine wave over dc), but that part works as expected.
However, if I output data from time=0, I don't get the slow rise I think I should. Shouldn't there be an initial current surge over R2 (and a corresponding slow voltage rise on the node between them) until C1 is charged? All I get is a constant sine-wave from the AC.
What is it that I'm doing wrong?
Thanks,
Jeff.
However, if I output data from time=0, I don't get the slow rise I think I should. Shouldn't there be an initial current surge over R2 (and a corresponding slow voltage rise on the node between them) until C1 is charged? All I get is a constant sine-wave from the AC.
What is it that I'm doing wrong?
Thanks,
Jeff.
Attachments
Examples:
Plot the DC voltage between nodes 1 and 2,
the voltage at node 3,
and the current through the voltage source, Vmeas
.PLOT DC V(1,2) V(3) I(Vmeas)
https://web.stanford.edu/class/ee133/handouts/general/spice_ref.pdf
You may need to use a PWL transient source for the DC part starting at t=0,
in series with an AC transient source also starting at t=0.
Last edited:
You are assuming that everything starts at zero. Unless explicitly instructed to do otherwise, LTSpice or any other simulator I know of first calculates a DC bias point and takes it from there. For stable circuits this is the response you would have got if the values you apply at t = 0 had been there from t = -infinity onwards.
- Status
- Not open for further replies.