Two Op-Amps 60 Hz Notch Filter
Notch filter is a filter that remove a certain B. Ideally a notch filter will remove only single point of frequency component, but practically it will remove a limited range of frequency spectrum. The spectrum should have very small bandwidth to approximate an ideal notch filter. The circuit diagram design below is based on passband gain of 3 and Q of 6. The opamps can be 741. By subtracting output signal of bandpass filter from its input signal, notch response is obtained. The most popular application of 60Hz notch filter is for removing powerline hum noise in audio, testing, measurement, or instrumentation system.