(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

Determine the transfer function for the circuit shown in figure 5 if the output voltage is defined as the voltage drop across the 20[tex]\Omega[/tex] resistor. Note there are two sources in this circuit.

2. Relevant equations

H(s) = [tex]\frac{Vo}{Vi}[/tex]

3. The attempt at a solution

From the previous question (I needed to find the Voltage and Current across the Inductor and the voltage across the Capacitor all in the 'S' domain) I know that, assuming V_{b}is the node voltage where the cap, inductor and resistor meet, V_{b}=[tex]\frac{120(5s^2+20s+11)}{s(s^2+5s+6)}[/tex] and, assuming V_{a}is the node voltage at the current source, V_{a}=[tex]\frac{60(11s^2+51s+22)}{s(s^2+5s+6)}[/tex].

Now what I'm having trouble with is determining what I should use for V_{i}. Every problem in my book or in class has defined an input voltage somewhere and all of them have only ever had one source. My idea is that I could use superposition to find the transfer function so I determine V_{o}when the current source is opened and V_{i}=[tex]\frac{60}{s}[/tex]V and then add that to the transfer function when the voltage source is shorted and V_{i}= V_{a}. Is this a valid approach?

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# Homework Help: Transfer Functions

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