Adjustable notch filter


Posted on Sep 9, 2012

In applications where the rejected signal might deviate slightly from the null on the notch network, it is advantageous to lower the Q of the network. This insures some rejection over a wider range of input frequencies. The figure shows a circuit where the Q may be varied from 0.3 to 50. A fraction of the output is fed back to R3 and C3 by a second voltage follower, and the notch Q is dependent on the amount of signal fed back.


Adjustable notch filter
Click here to download the full size of the above Circuit.

A second follower is necessary to drive the twin "T" from a low-resistance source so that the notch frequency and depth will not change with the potentiometer setting.




Leave Comment

characters left:

New Circuits

.

 


Popular Circuits

AVR FM Stereo Transmitter
Extension Phone Ringer
Fet Microphone Mixer Circuit
Arduino Knock
car headlights timer schematics
Dancing LEDs
Lead acid battery charger
WIEN BRIDGE OSCILLATOR CIRCUIT



Top