Electronic vital relay

A vital relay arrangement for a railroad system having a plurality of track sections connected to one another, each of the track sections being bounded by insulated joints, wherein signaling energy is provided to said track sections by a source, said source having line wires connected thereto, comprising:

• a control transformer for generating a track voltage signal, said track voltage signal being proportional to a track current on a first one of said track sections at a first location on said first one of said track sections, said signaling energy being provided to said first one of said track sections at a second location on said first one of said track sections;
• a local transformer for generating a local voltage signal, said local voltage signal being proportional to a local voltage on said line wires:
• means for converting said track voltage signal to a DC voltage;
• means for determining whether said DC voltage meets or exceeds a voltage threshold value;
• and
• means, independent of said means for determining whether said DC voltage meets or exceeds a voltage threshold value, for determining whether said track voltage signal and said local voltage signal are nominally in phase with one another;
• wherein said vital relay arrangement provides a first signal only if said DC voltage is determined to meet or exceed said voltage threshold value and said track voltage signal and said local voltage signal are determined to be nominally in phase with one another, said first signal being an indication that a train is not present in said first one of said track sections, that said first one of said track sections does not have a broken rail, and that the particular ones of said insulated joints that bound said first one of said track sections do not include a fault condition.