Abstract: An apparatus for the monitoring of physical quantities on systems for example for driving a quick-closing valve in turbines, wherein the monitoring itself is performed by monitoring channels which are interconnected in a majority-determining switching logic, primarily 2 of 3 system. The monitoring channels (I, II, III) are formed by a system-dependent number of identical solenoid valves (1, 2, 3).

Abstract: An apparatus for measuring and monitoring the angular velocity of the shaft of a rotating machine. In this apparatus, a plurality of sensors is positioned adjacent the shaft of the rotating machine for generating sequential pulses with periods proportional to the angular velocity of the shaft. The pulses are generated at intervals such that, during the period between adjacent pulses from one sensor, pulses are generated by each of the other sensors. An oscillator is provided for generating reference pulses at a predetermined pulse repetition rate, and a plurality of counting devices are coupled to respective sensors and to the output of the oscillator for counting the pulses generated by the oscillator. An averaging and reciprocal circuit is coupled to the output terminals of the counting devices for obtaining the average of the counting device outputs and then generating the reciprocal of the average value.