METHOD OF CHECKING TRACK CIRCUIT CONDITION Russian patent published in 2001 - IPC

FIELD: railway transport; checking condition of insulated sections of track circuit. SUBSTANCE: different-frequency signals are formed at supply end and are fed into track circuit. Signals are detected at relay end, are integrated and difference in signal levels of higher and lower frequency signals is determined. Difference is compared with pre-determined values of reference voltage corresponding to normal, shunting and control modes of operation. Condition of track circuit is determined by results of comparison. EFFECT: improved reliability of checking. 3 dwg