I'm putting together a project for school (ITT Tech Woburn MA) that deals with harmonics of certin tyes of waves. (square, triangle,sawtooth ect.) I need to design variable gain bandpass filters for 2kHz, 4kHz, 6kHz, 8kHz and 10kHz.
There are a few ways to do this, and I've found one way to do this with only one op amp.
http://www.elecdesign.com/Files/29/4481/Figure_01.gif
The only problem here is that they dont give any formulas for setting the center frequency or Q.
Anyone farmilure with this design?
I also had another thought to use a multiple feedback bandpass filter design.
http://www.captain.at/electronics/active-filter/
But that would mean I'd need twice the number of op amps to be able to vary the gain.
I could go sallen key but then I'd be upto 3 op amps per harmonic totaling 14 and theres only so much room on a breadboard.
anyone got suggestions?
There are a few ways to do this, and I've found one way to do this with only one op amp.
http://www.elecdesign.com/Files/29/4481/Figure_01.gif
The only problem here is that they dont give any formulas for setting the center frequency or Q.
Anyone farmilure with this design?
I also had another thought to use a multiple feedback bandpass filter design.
http://www.captain.at/electronics/active-filter/
But that would mean I'd need twice the number of op amps to be able to vary the gain.
I could go sallen key but then I'd be upto 3 op amps per harmonic totaling 14 and theres only so much room on a breadboard.
anyone got suggestions?