Patent · US Expired

Fluid pressure transducer

US4671116A · kind A · utility

20Cited by
11References
35Claims
0Family size

Assignee

Inventors

Key dates

Filing dateNov 30, 1984
Grant dateJun 9, 1987
Priority date
Expiry dateNov 30, 2004

Classification

  • Technology area (CPC D)Textiles; Paper
  • CPC primaryD06F39/087
  • WIPO fieldMeasurement
  • WIPO sectorInstruments

Abstract

A pressure transducer of the type providing a continuous electrical output signal indicative of the variation in sensed pressure having a metallic preferably aluminum armature attached for movement with a resilient pressure responsive diaphragm. A resonant circuit includes a coil disposed adjacent the armature and an oscillator provides current flow in the coil which generates eddy currents in the armature; and, movement of the diaphragm and armature causes the eddy currents therein to alter the effective inductive reactance of the coil and shift the frequency of resonance of the circuit. Circuit means are provided to emit an output signal indicative of the frequency shift for enabling a continuous determination to be made of the sensed pressure on the diaphragm. An auxiliary snap-action switch is provided remotely from the diaphragm and is actuated by a non-metallic rod from the armature passing through the central region of the coil. The circuitry is preferably mounted on a p.c. board disposed to have the switch rod pass therethrough.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.