US lawFederal (United States)RegulationsTitle 49 CFR — TransportationChapter II — FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATIONPart 236 — RULES, STANDARDS, AND INSTRUCTIONS GOVERNING THE INSTALLATION, INSPECTION, MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCESSubpart G — Definitions236.73149 C.F.R. § 236.731Controller, circuit.Last amended: 2017Year: 2026Length: 8 wordsOfficial source Cite as 49 C.F.R. § 236.731 (2026)A device for opening and closing electric circuits.Previous49 C.F.R. § 236.730Next49 C.F.R. § 236.732