The specific source of frequency interference, which occurs in RLC-elements of the nu-merical coding circuits for automatic locomotive signaling with a frequency of 50 Hz and au-dio-frequency track circuits, is analyzed. Experiments have shown that interference occurs when pulse overvoltages are applied in the power supply circuits and belong to the category of ferroresonance. The article considers a mathematical model using Fourier series expansion of the ferroresonant processes. With the help of this model and the MathCad 7.0 Professional soft-ware, computational experiments were performed, the results of which show that ferroresonant interference can not only interfere with the track receivers of audio-frequency track circuits and any other centralized traffic control devices, but also create conditions for their damage.
frequency interference, ferroresonance, tonal track circuits, numerical coding, RLC elements, mathematical models, signals, LEDs, protection, threshold elements