Input and Output Resistance (Electronics)

[Midas_Touch]

R_out
|-------------***------------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 kirchhoff 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.

 

[quantumdude]

I can't make heads or tails of your equation.

V_signal -R_out - V_out, perfect - R_n = 0

Do you mean this?

$$V_{signal}-R_{out}-V_{out,perfect}-R_n=0$$

That's what it looks like, but if that is in fact the equation that it makes no sense. You're subtracting voltages and resistances, which have totally different units.

 

[piercas]

The input and output resistance of a circuit are important characteristics that determine its behavior and performance. The input resistance, R_in, is the resistance seen by the input signal, while the output resistance, R_out, is the resistance seen by the output signal. These resistances play a crucial role in determining the overall gain and stability of the circuit.

When R_in is much larger than R_out, the input signal will see R_in as the main resistance and therefore the circuit will have a high input impedance. This means that the circuit will not draw much current from the input signal and will be less affected by changes in the input signal. This can be beneficial in certain applications, such as amplifiers, where a high input impedance is desired.

On the other hand, when R_in is much smaller than R_out, the output signal will see R_out as the main resistance and the circuit will have a low output impedance. This means that the circuit will be able to provide a large output current, making it suitable for driving other devices or components. This can be useful in applications such as power supplies or audio amplifiers.

When R_in is equal to R_out, the circuit will have a balanced impedance and will be able to efficiently transfer signals from the input to the output. This is important for maintaining signal integrity and minimizing losses in the circuit.

In summary, the input and output resistance of a circuit are important factors to consider when designing and analyzing electronic circuits. They can greatly impact the performance and behavior of the circuit and should be carefully chosen to meet the requirements of the application.