Mechanical displacement transducer
First Claim
1. A two-wire displacement converter circuit for converting a minute mechanical displacement to a DC current signal, comprising:
- a pair of first and second AC-excited reactive impedance elements, at least one of said first and second impedance elements having an impedance variable in response to said mechanical displacement;
means for supplying first and second DC current signals proportional to the impedances of said first and second impedance elements, respectively;
first means for supplying an output current signal corresponding to a difference between said first and second current signals and indicative of the amount of said mechanical displacement;
a third reactive impedance element having a fixed impedance;
second means for supplying a third current signal proportional to the impedance of said third impedance element; and
current regulating means for maintaining a sum of said third current signal and at least one of said first and second current signals at a predetermined value.
1 Assignment
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Accused Products
Abstract
A two-wire displacement converter for converting minute mechanical displacements to a DC output signal requiring no precision components yet providing a highly accurate output signal. A pair of first and second AC-excited reactive elements is provided, at least one of which has an impedance which varies in response to the mechanical displacement. DC signals proportional to the impedances of the first and second impedance elements are supplied to a differential amplifier, which produces an output signal having a magnitude related to the difference between the first and second current signals, and thus indicative of the amount of mechanical displacement. A current regulator circuit maintains a sum of a third current signal through a third reactive impedance element having a fixed impedance and at least one of the first and second current signals at a predetermined, fixed value.
9 Citations
7 Claims
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1. A two-wire displacement converter circuit for converting a minute mechanical displacement to a DC current signal, comprising:
- a pair of first and second AC-excited reactive impedance elements, at least one of said first and second impedance elements having an impedance variable in response to said mechanical displacement;
means for supplying first and second DC current signals proportional to the impedances of said first and second impedance elements, respectively;
first means for supplying an output current signal corresponding to a difference between said first and second current signals and indicative of the amount of said mechanical displacement;
a third reactive impedance element having a fixed impedance;
second means for supplying a third current signal proportional to the impedance of said third impedance element; and
current regulating means for maintaining a sum of said third current signal and at least one of said first and second current signals at a predetermined value. - View Dependent Claims (2, 3, 4, 5, 6, 7)
- a pair of first and second AC-excited reactive impedance elements, at least one of said first and second impedance elements having an impedance variable in response to said mechanical displacement;
Specification