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schematic

simulate this circuit – Schematic created using CircuitLab

Assuming the above circuit is given, and I need to find the voltage V on the capacitor for all t (v(t)). The controled current source is given by I=10^(-4) * v0 while v0 is the voltage on the resistor on the right. The switch turn right at t=0.

So, i figured easily that the voltage of the capacitor right before the switch turn right is 100v. And of course that after the switch turn right i get the circuit:

schematic

simulate this circuit

Now, I'm trying to use Thévenin's theorem in order to focus only on the capacitor. I know that i need to look for the voltage/current that drops/goes through the capacitor, but I can't seem to get there from KVL and KCL. I'm stuck with 3 parameters: V, V0, and I throught the capacitor. Did I figured the whole thing wrong? Any tips/advices please. Thanks.

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  • \$\begingroup\$ Try to first create the equivalent circuit in the laplace domain. When you have that it should be straihtforward. Well if you know how to do it, if you don't you should learn it because it can be a nice tool. \$\endgroup\$
    – WalyKu
    May 12, 2014 at 16:29

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Well, figured it out. for Thévenin's theorem to work, it is needed to ignore the capacitor (the load). And then, the solution is simple. shortning the capacitor makes it clear the the current and the voltage for Thévenin's theorem is zero, after that it is easy to calculate the resistance with a testing voltage source.

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