Resonance Frequency

[MikaM]

Hi every one
this is the anwser i've got:
the Laplace transform of the transmission function of this HP filter is:

the equation of HPFilter in secord order system equals to (secod order equation S)/(s^2+bw*s+w0^2)
==> (Rs+Rc)/(LCRc) = w0^2
in the bottom left corner of the equation
bw is the bandwidth

also i forgot to add that Rc >> Rs

 

[Ratch]

Hi every one
this is the anwser i've got:
the Laplace transform of the transmission function of this HP filter is:
View attachment 20641
the equation of HPFilter in secord order system equals to (secod order equation S)/(s^2+bw*s+w0^2)
==> (Rs+Rc)/(LCRc) = w0^2
in the bottom left corner of the equation
bw is the bandwidth

also i forgot to add that Rc >> Rs

Wait a minute. You first asked for the resonant frequency, and now you are treating it like a high pass filter, which means computing a transfer function. Which is it? You should make your questions clearer so we know what you want.

Ratch

 

[Laplace]

So I found the transfer function from the circuit node equation and made a Bode plot for some representative RLC values. But it is not too clear what is useful about the calculated 'resonance' frequency.

 

[MikaM]

you are right Ratch
and thank you "Laplace" for the detailed explanation.

im was also confused and i exposed to more details.
actually it is about 3 different filter HP LP and BP that have the same features and built by the same components.

any way, this discussion helped me a lot to understand
thank to all