# parallel RLC fourier transform

Discussion in 'Homework Help' started by ann93, Dec 26, 2014.

1. ### ann93 Thread Starter New Member

Dec 26, 2014
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0
hi. I have no idea where to start because I am very poor at fourier transform. So this is the question

According to the Fourier transform, design the parallel RLC circuit based on the following specifications of the design:

· use current source, Is(t) as power supply.
· assume the output current is measured at any component.
· the magnitude of the transfer function, |H(w)| = 1 at inductance, L = 2 H, resistor,R = 5 Ω, frequency, f = 10 kHz

Find the value of circuit components and transfer function of the circuit, H(w). Predict and discuss the effect to design if the power supply changed to the voltage source.

2. ### shteii01 AAC Fanatic!

Feb 19, 2010
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"· the magnitude of the transfer function, |H(w)| = 1 at inductance, L = 2 H, resistor,R = 5 Ω, frequency, f = 10 kHz"
This part does not make sense. Probably due to how you use punctuations. Break it down so that people can understand which numbers go with which statements.

3. ### WBahn Moderator

Mar 31, 2012
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4,920
If I'm reading it correctly, there are actually three transfer functions in question, namely a separate one for the current through each of the three components. The goal is then to size the capacitor so that the magnitude of each of the three transfer functions is unity.

4. ### MrAl Distinguished Member

Jun 17, 2014
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525
Hi,

Which sounds very hard to do seeing as how the resistor is in parallel to the current source too
Maybe something is wrong with the way the question is posed.

5. ### WBahn Moderator

Mar 31, 2012
18,096
4,920
That was my initial thought, but keep in mind that the currents don't need to be in phase.

I'm more concerned about whether the component values that are given make it possible as you have two constraints you need to meet (making the resistor take all the in-phase current and making the other two shuttle the appropriate amount of out-of-phase current between them). But they only give you one parameter to play with, meaning that the inductor value they picked must be correct for the frequency they chose, and I don't think that it is.

6. ### MrAl Distinguished Member

Jun 17, 2014
2,581
525

Hi,

Yes, very good, and i have to agree with you because the OP is stating |H(w)| not H(s) as i was originally thinking.