The microphone is used to measure the acoustic noise from an induction motor in an area of high electrical interference (50 Hz) and broadband white noise. The motor is running at 2400rpm and produces noise both at this frequency (fundamental) and at harmonics up to 600 Hz and is analysed using a PC.
a) Determine a suitable sampling frequency. Design a notch filter to remove the 50Hz component, paying particular attention to any assumptions you have made in the design.
b) Implement the filter in Matlab and determine the bode response of the system and comment on your results, particularly the width of the notch.
c) Implement the filter in Simulink and using a signal source containing both 50Hz and 55Hz of rms amplitudes 1 and 0.1 respectively. Determine the output of the filter and comment critically on your results.