Python notch filter

1. What is notch in Python?
2. How do you make a notch filter?
3. What is a notch filter used for?
4. What does a 60 Hz notch filter do?

What is notch in Python?

The epoch is the point where the time starts, the return value of time.gmtime(0) . It is January 1, 1970, 00:00:00 (UTC) on all platforms.

How do you make a notch filter?

One way to build a notch filter is to construct it as a band-pass filter whose output is subtracted from the input (1 – BP). Another way is with cascaded low-pass and high-pass sections, especially for the band-reject (wideband) case. In this case, the sections are in parallel, and the output is the difference.

What is a notch filter used for?

Notch filters are used to remove a single frequency or a narrow band of frequencies. In audio systems, a notch filter can be used to remove interfering frequencies such as powerline hum. Notch filters can also be used to remove a specific interfering frequency in radio receivers and software-defined radio.

What does a 60 Hz notch filter do?

Notch filters can be useful on the command for a fixed-frequency noise source such as that from line frequency (50 or 60 Hz) noise. Notch filters are also used to remove resonances from the system. Both notch and low-pass filters can cure resonance; notch filters do so while creating less phase lag in the control loop.