Resonant pressure sensor

Claim 2

In a pressure transducer including a diaphragm having a variable self resonant frequency wherein said frequency is correlated to pressure differential across said diaphragm and wherein said frequency can occur in at least one vibrational mode, characterized in that one portion of said diaphragm moves in a first direction while a second portion of said diaphragm moves simultaneously in a second direction, means for maintaining vibration of said diaphragm in said at least one vibrational mode comprising: converting means operatively coupled to said one portion of said diaphragm for converting mechanical oscillations into an electrical output; drive means operatively coupled to said second portion of said diaphragm for exciting said diaphragm to vibrate in response to an electrical signal; and, electrical means responsive to said electrical output for generating said electrical signal.

Claim 3

The pressure transducer of claim 1 wherein said electrical means comprises means for generating said electrical signal phased to drive the portion of said diaphragm coupled to said drive means in an opposite direction than the direction in which the portion of said diaphragm coupled to said converting means is simultaneously moving.

Claim 4

The pressure transducer of claim 2 wherein said electrical means includes filter means for generating said electrical signal only within a predetermined frequency band.

Claim 5

The pressure transducer of claim 2 wherein said diaphragm is a rolled metallic alloy having a rolling axis, and wherein an imaginary straight line through said converting means and said drive means is perpendicular to said axis.

Claim 6

The pressure transducer of claim 1 wherein said at least one vibrational mode is characterized by at least one nodal diameter, said one portion being to one side of said nodal diameter and said second portion being to the other side of said nodal diameter.

Claim 7

A vibrating diaphragm pressure transducer operable in the f11 vibrational mode having a single nodal diameter comprising: a diaphragm having a variable self resonant frequency characteristic; means for impressing fluid pressure differential across said diaphragm; converting means operatively coupled to a first portion of said diaphragm to one side of said nodal diameter for converting mechanical oscillations of said diaphragm into an electrical output; drive means operatively coupled to a second portion of said diaphragm to the other side of said nodal diameter for exciting said diaphragm to vibrate in response to an electrical signal; and, electrical means responsive to said electrical output for generating said electrical signal phased with respect to said electrical output so that said drive means drives said second portion of said diaphragm in a direction opposite to the simultaneous direction of movement of said first portion.

Claim 8

A vibrating diaphragm pressure transducer operable in the f11 vibrational mode having a single nodal diameter comprising: a diaphragm having a variable self resonant frequency characteristic; means for impressing fluid pressure differential across said diaphragm; converting means operatively coupled to a first portion of said diaphragm to one side of said nodal diameter for converting mechanical oscillations of said diaphragm into an electrical output; drive means operatively coupled to a second portion of said diaphragm to the other side of said nodal diameter for exciting said diaphragm to vibrate in response to an electrical signal; and, electrical means responsive to said electrical output for generating said electrical signal phased with respect to said electrical output so that said drive means drives said second portion of said diaphragm in a direction opposite to the simultaneous direction of movement of said first portion.

Claim 9

The vibrating diaphragm pressure transducer of claim 6 wherein said diaphragm is a rolled metallic alloy having a rolling axis and wherein said nodal diameter is substantially parallel with said rolling axis.

Claim 10

The vibrating diaphragm pressure transducer of claim 6 wherein said electrical means includes a filter whereby said electrical signal is contained within a predetermined frequency band related to the f11 vibrational mode frequencies.

Claim 11

The vibrating diaphragm pressure transducer of claim 6 with additionally further means coupleD to said first portion of said diaphragm and responsive to said electrical signal for driving said first portion in a direction opposite to the direction in which said second portion is simultaneously driven by said drive means.