Fourier analysis on critical damp resistance in transient process of RLC series circuit

The reason of deviation between theoretical critical damp resistance and experimental one is analyzed. The critical damp current is expanded Fourier integral of continuous frequency spectrum by Fourier transform, the Fourier integral of critical damping current are separated the Fourier polynomial of finite harmonics of discrete frequency by sampling. The loss resistance of inductor and capacitor are measured when the first harmonic and the harmonics which replace the critical damp current are applied to the RLC series circuit, the experimental value of critical damp resistance is amended, so as to the agreement between the amended experimental value of critical damp resistance and the theoretical one can be obtained.