# Maximizing voltage across a load resistor?

1. Feb 22, 2010

### Mugged

Hey, so I have this loop circuit that has some input voltage V in series with a resistor with a resistance of R and another in series resistor that is my load resistance, lets call it G. V and R are not variables, only G is.

I know that because of Jacobi's law, to maximize the power dissipated by the load resistance, you have to have G = R.

But I'm wondering how i should maximize the voltage drop across the load resistor? I just can't figure out how to write an equation and go from there.

Also, how can i maximize the current going into the load resistor?

Thanks

2. Feb 22, 2010

### Staff: Mentor

What is the voltage divider equation? That is what you use to do what you are asking about.

Assuming that V and Rs are fixed, you maximize the output voltage with an ______ circuit, and maximize the output current (a different situation) with a _______ circuit.

3. Feb 23, 2010

### Mugged

You mean kirchoffs voltage eqn?

Its V - IR - IG = 0

im starting to think that i can maximize the voltage drop on the load resistor G by maximizing the resistance of G though...still don't know if thats right.

4. Feb 23, 2010

### mmmboh

The voltage drop across the load resistor is given by VG=VG/(R+G), to find the maximum value of this function find when the derivative equals zero, so when R/(R+G)2= 0, which is when G equals infinity...basically the bigger the resistance the bigger the voltage drop across it.. if I am understanding your question..now to maximize the current going into the load resistor, well I=V/(R+G)...what would give a maximum value for I if G is the only variable?

5. Feb 23, 2010

### Mugged

OH! so minimizing R+G for current..i see.

Thanks a lot guys.