The discussion revolves around the method for determining the Thevenin Equivalent resistance (RTH) in a circuit that includes dependent sources. Participants are exploring the theoretical and practical aspects of applying Thevenin's theorem, particularly in circuits with dependent sources, and how to measure resistance in such scenarios.
Participants express differing views on the treatment of dependent versus independent sources in the context of measuring Thevenin resistance. There is no consensus on the correct approach, and the discussion remains unresolved.
Participants have not clarified certain assumptions regarding the circuit configuration or the specific roles of the dependent sources, which may affect the analysis. The discussion includes unresolved mathematical steps and varying interpretations of Thevenin's theorem application.
Metaleer said:I haven't looked at the circuit, but since you say it has dependent sources, the usual way to go about this is to connect a voltage source of generic EMF e_g between the two points, turn off all the independent sources, and then solve this circuit. Now, you use R_\text{Th} = \frac{e_g}{i_g} where i_g is the current going through the voltage source, where active references are used for voltage and current. If you've done everything right, e_g will be a linear function of i_g and you can simplify when you do the division.
This is for the Thévenin resistance - for the Thévenin EMF, all you need is the voltage drop between the two points when you open the circuit, as always.
Hope this helps. :)
Neandethal00 said:I'm not sure if we have to treat a dependent source differently from a independent source when measuring resistance. Because you can also find a non-zero resistance in independent sources using your formula
R = \frac{V}{I}.
Dependent source definitely contributes to V_\text{Th}.
For the circuit I see,
Rth = 2//8 = 1.6 ohms.