US3641414A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Transducer system with floating input circuit and constant current output electronics
Assignee: United Control Corp
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Filing: 1970-10-16
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Granted: 1972-02-08
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Expires: 1990-10-16
Abstract
Abstract A servoed transducer system uses differential sensing capacitors to detect the movement of a pivoted seismic mass. Electrostatic forces across the sensing capacitors are reduced by electrically floating the capacitors and using stray capacitance to a torque coil on the seismic mass to complete a pickoff sensor and detector circuit which generates an error signal in response to movement of the seismic mass. A servoamplifier maintains a constant current through the torque coil for a fixed error signal in order to rebalance the seismic mass.
Inventors
- 👤 Burton J Thompson
- 👤 Melvin O Eide
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 22:49
CPC Classifications
G; G01; G01P; G01P15/00; G01P15/02; G01P15/08; G01P15/13; G01P15/132; H; H03; H03F; H03F1/00; H03F1/34; H03F3/00; H03F3/181; H03F3/183
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
159 words
In a servoed system having a transducer for producing between two elements a variable electrical quantity proportional to movement of a seismic mass from a null position in response to an unbalanced force, and rebalance means for causing said seismic mass to move in proportion to current therethrough, the improvement comprising: servoamplifier means for passing current through said rebalance means to move said seismic mass to the null position when said transducer is effectively coupled to detecting means, including means operative independent of said rebalance means for maintaining the current through said rebalance means substantially constant for a fixed unbalance force, conductor means coupling one of said elements to said detecting means, circuit means coupling said rebalance means to said detecting means; and mounting means locating the other of said elements and said rebalance means in spaced relation to produce a stray capacitance therebetween sufficient to electrically couple said other element to said detecting means through said circuit means.
Claim 2
Dependent Claim
159 words
In a servoed system having a transducer for producing between two elements a variable electrical quantity proportional to movement of a seismic mass from a null position in response to an unbalanced force, and rebalance means for causing said seismic mass to move in proportion to current therethrough, the improvement comprising: servoamplifier means for passing current through said rebalance means to move said seismic mass to the null position when said transducer is effectively coupled to detecting means, including means operative independent of said rebalance means for maintaining the current through said rebalance means substantially constant for a fixed unbalance force, conductor means coupling one of said elements to said detecting means, circuit means coupling said rebalance means to said detecting means; and mounting means locating the other of said elements and said rebalance means in spaced relation to produce a stray capacitance therebetween sufficient to electrically couple said other element to said detecting means through said circuit means.
Claim 3
Dependent Claim
55 words
The improvement of claim 1 wherein said transducer produces between said two elements a variable reactive impedance corresponding to said variable electrical quantity, said detecting means includes oscillator means producing an AC signal and means including said conductor means, said circuit means, and said stray capacitance for coupling said oscillator means across said two elements.
Claim 4
Dependent Claim
68 words
The improvement of claim 1 wherein the seismic mass of said transducer means is movable with respect to base means, means affixing a first of said elements to said base means, means affixing a second of said elements to said seismic mass, and said mounting means locates said rebalance means on said seismic mass and spaced sufficiently adjacent said second of said elements to produce said stray capacitance.
Claim 5
Dependent Claim
61 words
The improvement of claim 3 wherein said mounting means comprises a bobbin forming a portion of said seismic mass and having a planar conductive surface corresponding to said second element, said rebalance winding means being wound on said bobbin and electrically insulated from said conductive surface, and electric insulating means mounting said bobbin for movement with respect to said base means.
Claim 6
Dependent Claim
66 words
The improvement of claim 1 wherein said detecting means produces an error signal proportional to the movement of said seismic mass away from said null position, and said current maintaining means includes current-sensing means for generating a feedback signal proportional to current through said rebalance means, and feedback means connecting said current-sensing means to said servoamplifier means for subtracting said feedback signal from said error signal.
Claim 7
Dependent Claim
70 words
The improvement of claim 5 wherein said servo amplifier means includes differential amplifying means with a pair of inputs and an output and having an output signal proportional to the difference between signals at the pair of inputs, means connecting said detecting means to one of said inputs, said feedback means connecting said current-sensing means to the other of said inputs, and said output being coupled to said rebalance means.
Claim 8
Dependent Claim
122 words
In a servoed system having a transducer for producing between spaced elements a variable reactive impedance proportional to movement of a seismic mass from a null position in response to an unbalance force, and rebalance means for causing said seismic mass to move in proportion to current therethrough, the improvement comprising: servoamplifier means for passing current through said rebalance means to move said seismic mass to the null position, including means for electrically floating and electrically referencing said elements to said rebalance means to reduce electrostatic forces across said spaced elements when current is passing through said rebalance means, and means operative independent of said rebalance means for maintaining the current through said rebalance means substantially constant for a fixed unbalance force.
Claim 9
Dependent Claim
122 words
In a servoed system having a transducer for producing between spaced elements a variable reactive impedance proportional to movement of a seismic mass from a null position in response to an unbalance force, and rebalance means for causing said seismic mass to move in proportion to current therethrough, the improvement comprising: servoamplifier means for passing current through said rebalance means to move said seismic mass to the null position, including means for electrically floating and electrically referencing said elements to said rebalance means to reduce electrostatic forces across said spaced elements when current is passing through said rebalance means, and means operative independent of said rebalance means for maintaining the current through said rebalance means substantially constant for a fixed unbalance force.
Claim 10
Dependent Claim
105 words
The improvement of claim 7 wherein said servo amplifier means includes detecting means effective when coupled to said transducer for producing an error signal amplified by said servo amplifier means to produce said current which passes through said rebalance means, and said floating and referencing means includes conductor means coupling one of said elements to said detecting means, circuit means coupling said rebalance means to said detecting means, and mounting means locating the other of said elements and said rebalance means in spaced relation to produce a stray capacitance therebetween sufficient to electrically couple said other element to said detecting means through said circuit means.
Claim 11
Dependent Claim
129 words
The improvement of claim 8 wherein said rebalance means comprises a torque coil wound between a pair of terminals, said servo amplifier means includes differential amplifying means for generating at an output a signal proportional to the difference between signals at a pair of inputs, means connecting said detecting means to one of said pair of inputs, means connecting in series the output of said differential amplifying means, said pair of terminals of said torque coil, and a resistive means forming a part of said current maintaining means, said current maintaining means further includes feedback means coupling said resistive means to the other of said pair of inputs, and said circuit means is coupled between said detecting means and one of said pair of terminals of said torque coil.
Claim 12
Dependent Claim
79 words
The improvement of claim 7 wherein said transducer comprises capacitor means having a first capacitor plate affixed to said seismic mass and a second capacitor plate affixed to base means, said first and second plates corresponding to said spaced elements, movement of said seismic mass with respect to said base means varying the capacitive reactance between said first and second capacitor plate means, said floating and referencing means reducing electrostatic forces across said first and second capacitor plate means.
Claim 13
Dependent Claim
97 words
The improvement of claim 10 wherein said servoamplifier means includes an AC detector for producing an output signal in proportion to the capacitive reactance between said first and second capacitor plate means, amplifier means for amplyifying said output signal to generate said current which passes through said rebalance means, oscillator means for generating an AC signal, said floating and referencing means includes stray capacitance means forming a sole electrical path to said first capacitor plate means, and circuit means including said stray capacitance means for coupling said capacitor means to said oscillator meaNs and said AC detector.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-02-07 | 1975-08-09 | 1976-02-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-02-07 | 1979-08-09 | 1980-02-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-02-07 | 1983-08-09 | 1984-02-08 | $7700.00 | Window Closed / Lapsed |