US Government as Represented by the Secretary of the Army

Charles E Paras

Francis M Manion

Tadeusz M Drzewiecki

Richard M Phillippi

A trim circuit for compensating for null offset of the jet stream in a flic transducer, such as an amplifier or jet deflection sensor, includes a flow bias control circuit and a supply sensitive difference flow control circuit. The flow bias control circuit supplies fluid pressure to a pair of symetrically disposed control channels at the input end of the transducer. This fluid pressure tends to decrease the amount of null offset of the jet stream from a central axis of the transducer which intersects a pair of symetrically disposed output channels. The supply sensitive difference flow control circuit removes the null offset remaining after correction by the flow bias control circuit. The supply sensitive difference flow control circuit may be disposed in one of the later stages of a cascaded fluidic amplifier chain or at the control inputs of a single stage transducer or amplifier.

Null balancing for fluidic sensors and amplifiers

The temperature sensors shown utilize a constant frequency fluidic oscillr to excite resonance tubes, whose frequency response is a function of temperature. The outputs of these sensors control a fluidic amplifier, whose output is rectified and filtered to produce a D.C. fluid signal which is a function of the sensed temperature. Different embodiments utilize resonance tubes excited in phase or 180.degree. out of phase to sense the difference between two temperatures or to provide increased sensitivity.

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Suitland, MD, United States of America

Charles E Paras