CURRENT MEASURING APPARATUS OF TRACK CIRCUIT FOR DETECTING CURRENT LEVELS OF RAIL AND DISCONTINUOUS LOOP WITHIN TRAIN

摘要

PURPOSE: A current measuring apparatus of a track circuit is provided to monitor an abnormal state of a current level by detecting and determining the current level on a rail and a discontinuous loop of the track circuit. CONSTITUTION: An antenna(230,240) is used for detecting currents from a rail and a discontinuous loop and converting the currents to voltage signals. An impedance matching unit(221) matches impedance between the antenna and a measurement device. An amplifier(222) is used for amplifying the impedance-matched signal according to a predetermined rate. A first filter(223) is used for removing undesired noise from the impedance-matched signal. A rectification/smoothing unit(224) detects a signal level from the filtered signal. A second filter(225) is used for removing an undesired signal from the detected signal level. A comparator(227) is used for comparing an output signal of the second filter with a reference signal. An indication unit(228) transmits a state of current to an external device.