TINA Fourier analysis

Hi, you can use the following:

Remember that                           Nc x Tin= Tsim= Ns x Ts   ( refer to my diagram at the end)

In TINA, in Fourier Spectrum,  once you choose number of samples ( say 1024), it automatically calculates  sampling frequency based on simulation time (Tsim).

But you have to pay attention to start and end points of your sim. It picks t=0 and end of sim for you as Tsim which is not correct ,

For example if you have a 1kHz input and pick 23 cycles, then  your “clean” simulation time is 23ms, but if you  run it for 25ms, TINA will pick 25ms!

And calculates the sampling frequency for that value  which is wrong!     So you have to specify the start and end yourself (considering the few cycles

You want to ignore at the beginning of simulation) then TINA will calculate the sampling frequency based on this Tsim and sampling frequency would be correct.

 Things to remember when you run transient for fft:

1-      Always discard the first few cycles , this way you start from “ good” waveforms.

2-      The bin resolution in fft plot (delta f) is inversely proportional to your simulation time.

3-      The longer your simulation time is, you have a better bin resolution but  you have to pick a higher  number of sampling points (Ns)

4-      Ns is an integer of power of 2

5-      It is recommended to choose a prime number of cycles , however I have done it without prime numbers and result is still holding pretty good.

Here is a plot that helps you to visulize it better:

Regards,

Arash