And the behavior of the circuit is the same

across those two terminals as the original one is.

So we use Thevenin Equivalent Circuits again when we want to simplify

part of a circuit to simplify our analysis.

The other reason we use Thevenin Equivalent Circuits is to find the load

that will maximize power to the load.

So in other words if I wanted to put a load resistor across right here or

to the original circuit right there then I would want to find

the Thevenin Equivalent Circuit and

that would tell me what load will maximize the power.

How do we build our Thevenin Equivalent Circuit?

Well it's shown over here, we're going need to define a few terms here.

We define V Thevenin, which is the voltage source here.

The R Thevenin is the resistance rate here.

Those are the elements of our Thevenin Equivalent Circuit and then I short

circuit or i sub sc is the current that relates these two through Ohm's law.

Now how do we find these from an actual circuit?

So if I took an actual circuit and I had my terminals coming out and I measured

the open circuit across here, and the open circuit voltage, that would be V Thevenin.

The other way I can find the other thing I need to find is the, I short circuit,

which is shorting out or just putting a wire across this and

measuring the current across those terminals.

That's i sub short circuit, and those two are both necessary in finding here.

And if I found those two through measurements, then I just can come back

through this relationship Ohm's law and find R Thevenin.

A lot of times in actual circuits it's easier to find

R Thevenin maybe analytically by doing a simple method here.

What I have to do is go to my original circuit,

this might be my original circuit.

I zero outsources