MAE 334 – LAB 5 7 Record these 2 value for a series of approximately 50 frequencies. You will find that the input V p-p will change slightly as you change the frequency. You do not need to readjust it, but you do need to record it! Before you begin vary the frequency over a wide range to determine at which point the output magnitude ratio is at the -3 dB point (V p-p_out / V p-p_in =0.707). This is approximately equal to your filter cutoff frequency, f c . Log this value in your notebook. In order to obtain a reasonably smooth transfer function curve concentrate on frequencies close to f c (take many closely spaced frequency points near f c and less closely spaced frequency points away from f c ). Be sure to take a frequency point at slightly above 1.x Hz and another as high as your ADC system will allow and still produce a smooth sine wave reconstruction. (5-15 KHz) When you sample the high frequency signals you will get better results if you enable only 1 channel at a time. (This allows the ADC to sample at its maximum rate of
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