BR933A Sep 1971
Specification for Miniature Tractive Armature AC Immune DC Slow Pick-up Neutral Line Relay Plug-In Type for Railway Signalling Purposes
This specification relates to the design requirements of miniature tractive armature D.C. slow pick-up neutral line relays for use in railway signalling circuits, irrespective of the presence in the circuit of alternating current at industrial frequency.
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- In Force: