Homework #12

Download a copy of  the JFF BLACK BOX vi from the on-line class notes. This is the BLACK BOX of your experiment. The VI generates several signals (including noise).   The output is in waveform data format.

Using Fourier transform and filtering techniques, can you extract the signals from the noise?

There are 3 signals hidden in the noise. Your job is to

(a) Identify the frequency and amplitude of the three signals. For this task you should study the data in the FREQUENCY domain.

(b) Of the three signals, which one is most likely to be noise which you might attribute to background room lights or a rotating motor? (HINT: at what frequency would you expect such as signal?)

(c) Using filters, use the appropriate filter type to isolate the HIGHEST frequency signal. To show that you have done this properly, plot the filtered data as a time domain waveform and verify that the data looks like a sine wave of the appropriate frequency. After looking at the frequency domain signals, consult the course notes and textbook to select the most appropriate filter to isolate the frequency.