RAILWAY DESIGNING OF RELAY LOGIC PRESENTATION

CIRCUITS-1

While designing the logic circuits conditions imposed in the control table are to be followed

Following guidelines are to be to be followed for various types of relay logic circuits.

* What is a meshed circuit and what are the risk factors to be considered?

* Special measures to retain a stored information during a power failure

* What is a stick circuit?

* Bridge paths

* Use of latched relays and types

* Polarized circuits.

* Necessity of time delay circuits and their application

* Various timing devices

* Timing problems in relay sequence.

* Designing of capacitor network.

* Various types of proving and necessity.

* Down-proving of relays in vital circuits.

* Various types of Cross proving of relays for conflicting functions and exemptions.

* Polarised circuits with biased relays

* Correspondence proving

* Sequence proving Used of repeat relays and care in using their contacts. Proving their back contacts

* Provision of multiple track repeat relays

* Delayed response of track functions

* Electrical isolation

* Limitation on length of circuits

* Safeguards with polarised circuits.

* Change over paths in meshed circuits

* Indication circuits