Patent ID: 8387925
Filing Date: 2013-03-05
Classification: B61L

Abstract:
1. A track circuit for railway systems comprising: a track segment of predetermined length and a plurality of track segments forming a railway; an electric joint connecting an end of the track segment to an end of an adjacent track segment, the electric joint comprising a conductor and being configured to electrically insulate the track segment from the adjacent track segment, the electric joint comprising two loops arranged in an S-shape and disposed longitudinally in a space between rails, the S-shape comprising arms extending toward the rails; a transmitting unit which transmits electric signal and a receiving unit each operatively coupled to the electric joint, the electric joint having connected thereto the transmitting unit and the receiving unit of the track segment and the transmitting unit and the receiving unit of the adjacent track segment; a ground-based transmitting unit comprised within the transmitting unit and a ground-based receiving unit comprised within the receiving unit, the ground-based transmitting and receiving units being configured to transmit and respectively receive high-frequency signals for detection of a train on the track segment; a second ground-based transmitting unit comprised within the transmitting unit and a second ground-based receiving unit comprised within the receiving unit, the second ground-based transmitting and receiving units being configured to transmit and respectively receive low-frequency signals forming a carrier encoded with information to be transmitted to a receiving unit in the train, wherein the high- and low-frequency signals are transmitted from the ground-based units to the train-based unit through the rails comprising the track segment when the train runs on the track segment; an enabling/disabling unit configured to alternately enable/disable the high-frequency signal transmitting and receiving units, and an enabling/disabling unit configured to enable/disable the low-frequency signal transmitting and receiving units; and an impedance disposed within the electric joint.