Bandstop Filter!

Dublin_Andy

Could someone create a bandstop filter to reduce the amplitude of frequencys to 0 between 17Hz and 32Hz???

Reply A.S.A.P please!

DublinDilbert

Dublin_Andy wrote: »

Could someone create a bandstop filter to reduce the amplitude of frequencys to 0 between 17Hz and 32Hz???

Reply A.S.A.P please!

The quick answer to your question is yes in theory some one could.

You'll need to specify the "roll off" of the filter, ie how fast of a cut off you need. You'll also need to specify what you mean by "0".

2011

I would think he means 0 dB

2011

You'll need to specify the "roll off" of the filter, ie how fast of a cut off you need. You'll also need to specify what you mean by "0".

I would think he means 0 dB.


You could build an active filter (using an op amp) or a passive filter.

DublinDilbert

You'll need quite a high order filter to achieve the "notch" type effect you want, as your "stop" band is only 32-17 = 15Hz

Dublin_Andy

the cut off is at -3db and decays at -20db per decade. we re trying an RC filter but dont know what values to specify for the resistor and capacitor.

Jonathan

Have a play around with this.

Dublin_Andy

thanks for the link jonathan

Red Alert

If you like, what you want is the cascade of a LPF and a HPF, assuming that they're both ideal. But that's a tiny frequency band you've got there.

Cheeble

I humbly beg to differ

This is a wideband filter design, the stopband being 65% of the geometric centre frequency. It's not a hard design to do, though component realisation could be a challenge.

I'm assuming you want an analog rather than digital filter?
Do you want a passive, or active design?
Input impedance?
Output impedance?
Source impedance?
Load impedance?
What shape do you want (e.g. flat in band, maximum roll off, constant phase, elliptical)?

Alternatively, what's it for so that we can work all of that out?

Cheeble-eers