Accession Number : ADD004281

Title :   Capacitive-Type Displacement and Pressure Sensitive Transducer.

Descriptive Note : Patent,

Corporate Author : DEPARTMENT OF THE NAVY WASHINGTON D C

Personal Author(s) : Liebermann,Leonard N

Report Date : 09 Aug 1977

Pagination or Media Count : 6

Abstract : The transducer functions as a capacitor to sense variations in inter-plate distances produced either by transducer displacement or by pressure. The capacitor plates include flexible rubber sheathing members having interior conductive surfaces spaced slightly from a conductive centrally-disposed metal plate. A pair of electrets are disposed one between each rubber surface and the central metal plate. Electrets are a battery replacement supplying a large electrostatic field. Opposite polarization of the electrets provides push-pull and directional capabilities. Like polarities, or the omission of one electrode, provide responsiveness both to pressure and to displacement. The central metal plate has sufficient mass to remain substantially stationary relative to the flexible movements of the rubber sheathing. Variations in the plate spacings produces variations in the capacitor output. (Author)

Descriptors :   *Patents, *Pressure transducers, *Transducers, *Capacitance, Displacement, Rubber, Electrets, metal plates

Subject Categories : Electrical and Electronic Equipment
      Test Facilities, Equipment and Methods
      Electricity and Magnetism

Distribution Statement : APPROVED FOR PUBLIC RELEASE