Pulsed DC circuit - has single central oscillator and counter which feed several tracks with freedom from mutual interference

摘要

A pulsed track current appts. has a system to prevent false responses. It does not require the use of a highly stabilised oscillator. It gives complete protection between the individual track circuits, and is able to avoid interaction between them. A control oscillator and a ring counter are used to give any desired sequences for the mutual isolation of the different track circuits. To prevent false responses each circuit has a pulse-shaper, a discriminator, a coincidence circuit and an electronic relay, the pulse shaper and the coincidence circuit being synchronised from the same pulse train.