graphic EQ not simulating how I planned :-( ...HELP

[Hywel]

Hi, I've attached a circuit that is supposed to give to peaks/notches (depending on where you have the potentiometers set)  in the frequency response of the input signal at 318Hz and 112Hz. I'm 100% sure the design is correct but I think I've screwed up, possibly with the function generator/bode plotter.

I've tried a few function generators. The Agilent function generator would benefit me most as it can pass noise to the circuit. This would allow me to to view the effect my circuit has on the frequency response of my input signal the best, I believe. However I can't get that or the standad function generator to work as I had hoped!

Any ideas from anybody out there would be greatly appreciated.

Many thanks, Hywel.

[kittmaster]

You have some conceputal issues with how op-amps work and how voltage sources operate.

First, the signal is clipped, your jamming 10Vpp into a rail limited 9V opamp.

Your generator frequency is set to 50Hz, hard to bode plot a frequency spread of 318Hz when the source only goes to 50!

Your voltage follower requires negative voltage, your only amplifying the POSITIVE side of the sine wave. If its ment to run on single supply then you need to decrease the amplitude and add an offset to the voltage source......there are so many other things, start there, it may get you going.......try using the OSCILLOSCOPE to troubleshoot the circuit from the front to back end.

Message Edited by kittmaster on 03-19-2008 09:17 PM