#### Midas_Touch

|-------------***------------o------------------|

|.........................................+........................|

|.................................V_signal.......................* R_in

-..V_out, perfect.............................................*

-...................................................................|

|...................................................................|

|.........................................-.........................|

|-----------------------------o------------------|

=.......(ground)................................................=

Say that circuit 1 is the left side of the above circuit (ignore the dots), and circuit 2 is the right side (R_in).

First I have to find V_signal using kirchoff rules

so I get V_signal -R_out - V_out, perfect - R_n = 0

But I am not sure what happens with R_in >> R_out, R_in << R_out or when R_in = R_out.