EP 0116293 B1 19880720 - MODULATION SYSTEM FOR RAILWAY CIRCUITS
Title (en)
MODULATION SYSTEM FOR RAILWAY CIRCUITS
Publication
Application
Priority
FR 8300429 A 19830113
Abstract (en)
[origin: ES8504582A1] A modulation system for railway track circuits in which a modulated signal is applied to a section of track for the purpose of detecting the presence or absence of a train on the section. Such circuits are used to control signalling and they are vital to safe operation of a railway. At a transmitter end, the output (19) of a power amplifier (18) is connected to a section of track. The power amplifier (18) receives the modulated signal from a modulator (17) which is itself controlled by a pseudorandom binary sequence generator comprising a clock (11), a shift register (10), and a modulo 2 adding circuit (13, 14, 15). Equivalent circuitry is used at a receiver end to recognize the pseudorandom sequence in the absence of a train on a given section of track. The likelihood of interference from a train on that section generating an interference signal capable of being mistakenly recognized for the absence of a train can be reduced to an arbitrarily low value.
IPC 1-7
IPC 8 full level
B61L 1/18 (2006.01)
CPC (source: EP US)
B61L 1/188 (2013.01 - EP US)
Designated contracting state (EPC)
DE FR GB IT NL
DOCDB simple family (publication)
EP 0116293 A1 19840822; EP 0116293 B1 19880720; DE 3472779 D1 19880825; ES 528870 A0 19850416; ES 8504582 A1 19850416; FR 2539372 A1 19840720; FR 2539372 B1 19850315; US 4582279 A 19860415
DOCDB simple family (application)
EP 84100273 A 19840112; DE 3472779 T 19840112; ES 528870 A 19840113; FR 8300429 A 19830113; US 57033984 A 19840113