The Frequency Spectrum of Electrical Sliding Contact Noise and Its Waveform Model

There are many unsolved problems concerning an electrical sliding contact noise. Some relationships between the sliding contact noise and the contact force, the contact resistance and the sliding velocity have been presented by Mano. The authors have proposed a relationship between the power spectrum and the sliding velocity of the sliding contact, supposing that the fluctuation of the contact resistance is regarded as a random step function and the distribution of its amplitude is regarded as Poisson distribution and Gaussian distribution. Furthermore, the possibility of the amplitude as being a Gaussian distribution is described. The actual power spectrum of sliding contact noise as measured and analyzed by the microcomputer is studied. The frequency characteristics of the sliding contact noise is obtained and it is proposed that it can be calculated by the random step function. It also is proposed that the noise waveform is modeled by the autoregressive process. Finally the simulated waveform using the autoregressive method compared with the real waveform of electrical sliding contact noise is discussed.