# Maths Of Gyrator And Bandaxall

Discussion in 'Homework Help' started by metricaez, Sep 22, 2009.

Sep 22, 2009
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2. ### Jony130 AAC Fanatic!

Feb 17, 2009
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Last edited: Sep 22, 2009

Oct 9, 2007
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4. ### Jony130 AAC Fanatic!

Feb 17, 2009
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Hmm,
$Zin=\frac{R_L*(R*R_L*C^2*\omega^2+1)}{1+ \omega^2*R_L^2*C^2} + \frac{ j\omega*R_L*C(R-R_L)}{1+ \omega^2*R_L^2*C^2 }$

5. ### The Electrician AAC Fanatic!

Oct 9, 2007
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What's wrong with the expression on the Wikipedia site?

They have:

$Zin=(R_L+j\omega*R_L*R*C)||(R+\frac{1}{j\omega*C})$

If you expand their expression and then rationalize, don't you get exactly the same as your expression?

6. ### metricaez Thread Starter New Member

Sep 22, 2009
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Hi!
I need the analysis and the formula for exactly those 2 circuits. The information you granted me had similar circuits but not the same (except for the bandaxall fourth link wich refers to the circuit I need). I know the gyrator circuit apears on Audio Radio Handbook by National Semiconductor. I would buy the book but it isnt sold here in Uruguay and as I m under 18 i dont have a credit card to buy it online.
If someone could scan the chapters of the book refered to that filter or/and analyse it I would be really thankfull.
Thanks again for the suport and forgive my English as I m a Spanish speaker.

PS: If you scan the book please send it to metricaez@hotmail.com

7. ### metricaez Thread Starter New Member

Sep 22, 2009
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And about the bandaxall if you could explain me how it works , i mean for example , "when R2 has a highter level, then c2 does this, and c3 does that and so on" telling me how capacitors and resistors afect the signal and the gain.
I know I m being a trouble but I m really needing help :S.
Thanks again