Abstract: A control system for moving a piston in a reciprocating piston respirator which utilizes predictive servo control techniques. Present invention uses nonlinear time domain analysis rather than linear frequency domain analysis to produce a predictive servo control system for precisely controlling the movement of a piston in a reciprocating piston respirator. A plurality of flow profiles can be produced using stored factor tables. Current pressure and position information are used in the predictive servo control system.

Abstract: A variable flow reciprocating piston respirator system which is capable of providing a substantially constant oxygen enrichment over an entire inspiration stroke of a variable flow respirator output. A proportional control valve is used to deliver oxygen from an oxygen supply tank to the output of a reciprocation piston pump. A microprocessor controls the magnitude of opening of the proportional valve to insure that a proper overall volume of the output is produced with the proper percentage of enrichment of oxygen.

Abstract: A coordinated traffic signal control system comprising a plurality of signalized intersections with controllers including coordination means to relate cycle timing between intersections without dedicated interconnecting communication channels. Coordination means including radio receiver tuned to receive broadcast standard time such as from National Bureau of Standards Station WWV, cycle timers related to data from broadcast time after iterative broadcast data check, signal cycle program selection from a plurality of programmable signal cycle program data inputs with cycle length and offset selection through time of day or traffic count program outputs, such a system providing fixed cycle timing relationship with other similarly equipped intersections that responds to anticipated or detected changes in traffic patterns.