Abstract: A fault-monitoring system for a large industrial conveyor belt to detect rips or other faults. There are fault-sensing units in the belt, each comprising a conductive loop extending across the belt and a sensing circuit. First and second frequency signals are directed to the fault sensor and the fault-responsive circuit sends a response of a frequency to indicate either a fault condition or a no-fault condition. Thus, the response from the fault sensor is either an “I am here and I am okay” or “I am here, but there is a fault in the belt” signal.

Abstract: A fault-monitoring system for a large industrial conveyor belt to detect rips or other faults. There are fault-sensing units in the belt, each comprising a conductive loop extending across the belt and a sensing circuit. First and second frequency signals are directed to the fault sensor and the fault-responsive circuit sends a response of a frequency to indicate either a fault condition or a no-fault condition. Thus, the response from the fault sensor is either an “I am here and I am okay” or “I am here, but there is a fault in the belt” signal.

Abstract: A fiber optic switching system which includes an optical switch having a movable actuator and a light fiber coupled to the actuator which terminates at an end surface thereof for conducting light from a light source to the optical switch mechanism. A flexible reflective film whose reflectivity is conditioned to provide at least two different reflective surfaces is positioned such that an end surface of the actuator abuts the film throughout its movement from one position to another. A detector detects light reflected from the film. The actuator is movable so as to direct light from the light fiber from the one reflective surface of the film to another and the detector detects light reflected from the film so as to determine which reflective surface of the film from which light has been reflected.