I would like some help understanding how to find the equivalent resistance of the circuit as shown in the included figure.

 

I also want to clarify another thing; when finding the input resistance for the section, do we completely ignore the other side (RHS) of the circuit? The reason I ask this, is that normally I solve for Vx and Ix at the Req point and then Req = Vx/Ix; in this case it is not possible to solve for Vx without using the RHS of the circuit.

 

Edited May 24, 201510 yr by CasualKilla

I assume you are looking for a Thevenin equivalent?

 

Does this help?

 

http://www.ittc.ku.edu/~jstiles/312/handouts/Example%20An%20Analysis%20of%20a%20pnp%20BJT%20Circuit.pdf

I assume you are looking for a Thevenin equivalent?

 

Does this help?

 

http://www.ittc.ku.edu/~jstiles/312/handouts/Example%20An%20Analysis%20of%20a%20pnp%20BJT%20Circuit.pdf

 

I think you are right, perhaps it is a Thevenin equivalent, if not, it is closely related, but what I need to do is pretty much need to replace the LHS of the circuit with a single resistor. I normally don't have any problems with these, but this particular example is giving me issues.

 

final result should look like this:

Not a single resistor you have a controlled current source on the LHS.

 

Thevenin would replace it with a voltage source in series with a resistor.

 

Norton would 'replace' it with a current source in parallel. Except you already have one.

 

Look up source transformation.

Edited May 25, 201510 yr by studiot

I appreciate you trying to point me in the right direction, but I understand the theory quite well, I have done probably 100's of similar problems, but I am just having trouble with this particular circuit, so I would appreciate some help tackling this particular problem.

 

Here is an example of how I normally solve these problems.

 

 

To give some context to why I need to do this, there is normally an capacitance in the circuit, so we need the equivalent resistance the capacitor experiences to find the time constant.

 

Edited May 25, 201510 yr by CasualKilla