Using the Fourier Series in a Circuits or DSP Laboratory

Laboratory experiments on circuits that exhibit transient effects are usually performed with a periodic input signal (like a square wave). Three experiments on a resistor capacitor (RC) filter using transient analysis and the solution of a first-order differential equation are described. The results according to a Fourier analysis are then reinterpreted. The similarities and differences in the results from the two theories provide a better understanding of both. Also, using Fourier analysis introduces the basic strengths and weaknesses of discrete signal processing. Further additions to this laboratory are discussed and include 1) the addition of more first-order linear circuits; 2) the addition of second-order (and higher-order) linear circuits; 3) the processing of all data in the frequency domain; and 4) the study of nonlinear circuits. Index Terms--Discrete signal processing, Fourier series, periodic function, phasor, RC filter, transient.