Hello to all,
I wanted to create a FFT for a resolver Signal. The excitation voltage has a frequency of 5kHz, so I expected one Peak to be at that point. But when I plot the FFT, the Peak is located at 10kHz? The lower frequency for the resolver revolutions seems to be right.
This is my code for generating the FFT:
%%FFT Resolver
Fs = 80000; fn = Fs/2; N = length(r_sin); df = Fs/N; x_fa = 0 : df : Fs-df; fft_sin = fftshift(abs(fft(r_sin, N))/N); fft_cos = fftshift(abs(fft(r_cos, N))/N); plot(x_fa-fn,[20*log10(fft_sin) 20*log10(fft_cos)]) title('Resolver FFT') xlabel('Frequency [Hz]') ylabel('Amplitude [dB]') legend('sin', 'cos') xlim([0 40000]) ylim([-150 -20])
Is my code wrong or is this the correct behavior?
Thanks a lot in advance!
Regards, Sven
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