Thevenin equivalent circuit in RC circuit with current and voltage source

[sean87]

I have the circuit below and I have to calculate complex current i1using thevenin equivalent circuit method:

I tried to follow the rules and open the terminal AB across the resistor:



I want to ask if this is a correct way to convert the circuit to thevenin. Also I am not sure is capacitor's reactance -4iis same as -4j or 4, 90 degree ?

Then The voltage across AB terminal would be equal to voltage across the capacitor? Is it ok to in this case see the voltage source as a short?

Thanks.

[Neganur]

If you're asked to use Thevenin's method - shouldn't you end up with just a voltage source and a series impedance?

[jsoderquist]

It's been a while, so don't hold me to it - but - I'm pretty sure it will simplify things if you use a combination of Thevenin and Superposition in order to analyze this circuit.

1. Open the current source, analyze the circuit.

2. Close the current source and short the voltage source, analyze the circuit.

3. Your answer should be the algebraic sum of the two.

Again, don't hold me to it, but that's what I seem to recall.

[jimmc]

Using Thevenin's theorem only...

1. Convert the current source and shunt resistor to the equivalent voltage source and series resistor.

2. You now have two voltage sources in series, combine them.

3. Calculate the current in the circuit (which will of course be the same as the current through the capacitor in the original circuit).

4. Combine this current with the current source I₁ to find the current through the resistor.

Jim