FLUID SIGNAL LIMITING DEVICE

A pneumatic signal limiter includes an integrated fluidic repeater and variable restrictor assembly having a pair of telescoping interconnected input and output body members with opposing and complementary recessed faces defining an input chamber and an output chamber to opposite sides of a diaphragm. The output portion includes an exhaust orifice and passageway within which a variable low limit restrictor is mounted to control the exhaust flow. The output body further includes an output passageway and intersecting exhaust passageway with an adjustable high limit restrictor connected directly to the exhaust passageway. The supply is connected to the output passageway in series with a restrictor through the intersecting passageway or a separate connection. Each restrictor is a needle valve which is adjustably secured within the housing with a conical point within a related limiter orifice. The threaded pin valve member has a relatively small cone angle and very fine adjusting threads. A closed loop control system includes a controller connected to sensors from a controlled variable source and from a master variable source through limiters. The controller is connected via a limiter to a control apparatus for the controlled variable unit.