Finding R_Thevenin involving dependent source

AI Thread Summary
The discussion focuses on finding the Thevenin equivalent resistance (R_Thevenin) in a circuit with a dependent source. The user initially excites the circuit with a 1A current source and attempts to derive the voltage across a capacitor, leading to an incorrect calculation of R_Thevenin. Feedback indicates that the error occurs after the source transformation, where the voltage across terminals does not account for the additional impedance between the transformed source and the terminals. It is emphasized that both the impedance from the transformation and the capacitor's impedance must be considered. Accurate identification of these components is crucial for obtaining the correct Thevenin resistance.
Bishamonten
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Homework Statement


upload_2017-5-14_19-23-33.png


Homework Equations



Impedances:

Inductor = jωL; Capacitor = 1/jωC

The Attempt at a Solution


I attempted to excite the circuit with an Io = 1A source, and then from Zc = 1/jX2 justify Vx = (1)(Zc)

Thus, substituting our found Vx and then doing a source transformation, we find our V = g(Vx)(jX1), and thus, our RTh = V/Io, which is not correct. The correct answer is #1 in the image.[/B]
 
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Bishamonten said:
I attempted to excite the circuit with an Io = 1A source, and then from Zc = 1/jX2 justify Vx = (1)(Zc)

Thus, substituting our found Vx and then doing a source transformation, we find our V = g(Vx)(jX1), and thus, our RTh = V/Io, which is not correct. The correct answer is #1 in the image.
Exciting the circuit with a current source is good. I think that where you've gone wrong is after your source transformation.
The voltage source from that transformation is not the potential that appears across ab. There are now two components between that source and the "a" terminal, the impedance X1 associated with the transformed source and the capacitor's X2.
 

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