# Transfer function with two nodes

Discussion in 'Homework Help' started by Schoppy, Jul 8, 2014.

1. ### Schoppy Thread Starter New Member

Jul 7, 2014
26
0
I need help starting it, I don't want the whole thing I just want a little nudge, I'm assuming we will do a superposition with node voltage but I have to get it into terms of V_in. V_out is obviously easy but I'm struggling to get going.

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2. ### anhnha Well-Known Member

Apr 19, 2012
783
49
Hi,

Can you calculate the voltage at the node where two resistors and one capacitor are jointed?

Let's call that voltage is V1.
You need to express V1 = Z1*Vin
Then you express Vout in terms of V1.
Vout = Z2*V1

From that we have: Vout = Z2*V1 = Z2*(Z1*Vin) = Z1*Z2*Vin
=> Vout/Vin = Z1*Z2

3. ### MrAl Distinguished Member

Jun 17, 2014
3,719
789
Hi,

Yes combining impedances is one way to handle this, combining the last resistor and last capacitor with the first capacitor to form a voltage divider to get v1, but what about simple nodal analysis? That's a general way to handle these kinds of networks.
Then there's also Thevenin and Norton.

4. ### Schoppy Thread Starter New Member

Jul 7, 2014
26
0
Yea I was able o solve it using nodal analysis it just took me some time to remember how to do it. Thanks guys!