Apparatus for verifying numerical messages used primarily in railway traffic control system

摘要

The fail safe validation technique controls the identity of two digital signals. One digital signal (A) is applied to one side of a Wheatstone bridge (2), whilst an inverted signal B is applied to the opposite side of the diode bridge. The output passes through a static relay (5) and an amplifier (6) to provide a secure "all or nothing" output signal S.