FFT and input voltage

1. What is the input and output of FFT?
2. What is the output of FFT?
3. What does FFT do to data?
4. What does FFT plot show?

What is the input and output of FFT?

You can find more information on the FFT functions used in the reference here, but at a high level the FFT takes as input a number of samples from a signal (the time domain representation) and produces as output the intensity at corresponding frequencies (the frequency domain representation).

What is the output of FFT?

It just means that the signal is "flipped" -- a standard FFT is based on a cosine, which normally has value = 1 at t = 0, so a signal which had value = -1 at time = 0 would have a negative amplitude.

What does FFT do to data?

It transforms time-domain data into the frequency domain by taking apart a signal into sine and cosine waves. In a complex signal, the FFT helps the engineer to determine the frequencies that are being excited and the amplitude at each frequency.

What does FFT plot show?

Frequency-domain graphs– also called spectrum plots and Fast Fourier transform graphs (FFT graphs for short)- show which frequencies are present in a vibration during a certain period of time.