Global Patent Index - EP 0116293 A1

EP 0116293 A1 1984-08-22 - Modulation system for railway circuits.

Title (en)

Modulation system for railway circuits.

Title (de)

Modulationssystem für Eisenbahnstromkreise.

Title (fr)

Système de modulation pour circuits de voie ferroviaires.

Publication

EP 0116293 A1 (FR)

Application

EP 84100273 A

Priority

FR 8300429 A

Abstract (en)

[origin: US4582279A] 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.

Abstract (fr)

Système de modulation pour circuits de voie ferroviaires comprenant chacun un émetteur (17) de signaux modulés en fréquence ou par impulsions, Chaque émetteur comporte un générateur (10, 11, 13, 14, 15) de séries binaires pseudo-aléatoires, le changement de fréquence ou de parité d'impulsion s'effectuant au rythme des changements de valeur binaire. Application : contrôle et sécurité ferroviaires.

IPC 1-7

B61L 1/18

IPC 8 full level

B61L 1/18 (2006.01)

CPC

B61L 1/188 (2013.01)

Citation (search report)

Designated contracting state (EPC)

DE FR GB IT NL

DOCDB simple family

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