Simulate Sadiku's book Exercise

Hello, good morning.

Im trying to simulate an exercise about rc first order circuits, and Im get some wrong results.

The circuit from book is:

And I used a switch from @KSKelvin to close ab nodes.

The v(0) capacitor voltage is 15v. Its correct as the book says, but the v(t), in t = 4s, must be 27.97 V, and I’m gettin 15 V.

May some show me what Im doing wrong?

Check your initial conditions.

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Do you mean setup .ic C1=0?

Got same issue:

Sometime, garbage in garbage out.
Your schematic does not match the circuit in your book. The common connection of the single-pole double-throw (SPDT) switch should be with the capacitor and not R2.

SadikuExercise.qsch (10.8 KB)

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Hello. Thank you for your reply. I really appreciate. I’ll do the modifications here.

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This will help a lot to migrate the pspice examples to qspice. Thank you very much.

Results:

A simple trick, double click marker label, input “4” and Enter, the marker can jump right at 4s.

image

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