US3667033A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Cryogenic single sensor three component magnetometer
Assignee: United States Department of the Navy
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Filing: 1971-04-06
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Granted: 1972-05-30
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Expires: 1991-04-06
Abstract
Abstract This invention relates to an improved magnetometer using sense loops of superconducting wire. A Josephson device is used to sense the induced current flowing in the wire and to control a bucking current to nullify the current flowing in the loop. The amount of current required to reduce the current to zero is used as a measure of the intensity of the magnetic field inducing the superconducting current flow. A system for sharing a single Josephson device in a plurality of sense loops is a component part of the system of the invention.
Inventors
- 👤 Charles R Davis
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 02:37
CPC Classifications
G; G01; G01R; G01R33/00; G01R33/02; G01R33/035; G01R33/0354; Y; Y10; Y10S; Y10S505/00; Y10S505/825; Y10S505/842; Y10S505/843; Y10S505/845
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
337 words
An improved magnetometer comprising in combination: a plurality of superconductor sEnsor means having superconducting electrical current flowing therein, having a predetermined orientation with respect to each other, and having a predetermined spatial orientation in a medium having a magnetic field therein for sensing variations thereof; single transducer means responsive to variations of said superconducting electrical current flowing within said superconducting sensor means for producing an output signal in response thereto; first switching means connected between said superconductor sensing means and said single transducer means for selectively connecting said transducer means with a single one of said superconductor sensor means without significant interruption of said superconducting current flow therein; means connected to said single transducer means in such manner as to receive the output signal therefrom for increasing the electrical power thereof; a plurality of sample and hold circuit means for receipt and storage of the output of said amplification means; second switching means connected between said amplification means and said plurality of sample and hold circuit means for selective connection of the output of said amplification means to a selected one of said sample and hold circuit as an input thereto; calibration coil means disposed in cooperative relationship with each of said plurality of superconductor means for inducing an opposing current therein; third switching means connecting said plurality of sample and hold circuit means and each of said calibration coil means for selective signal transfer therebetween, whereby the increased power signal is used to cancel out the superconducting electrical current flowing in a selected one of said superconductor sensor means; readout means for indicating the value of the signal stored in individual ones of said sample and store circuit means; fourth switching means connected between said plurality of sample and hold means and said readout means for providing selective connection between said readout means and a single one of said plurality of sample and hold means; and sequencer circuit means connected in circuit relationship with said first, second, third, and fourth switch means for synchronous operation thereof.
Claim 2
Dependent Claim
337 words
An improved magnetometer comprising in combination: a plurality of superconductor sEnsor means having superconducting electrical current flowing therein, having a predetermined orientation with respect to each other, and having a predetermined spatial orientation in a medium having a magnetic field therein for sensing variations thereof; single transducer means responsive to variations of said superconducting electrical current flowing within said superconducting sensor means for producing an output signal in response thereto; first switching means connected between said superconductor sensing means and said single transducer means for selectively connecting said transducer means with a single one of said superconductor sensor means without significant interruption of said superconducting current flow therein; means connected to said single transducer means in such manner as to receive the output signal therefrom for increasing the electrical power thereof; a plurality of sample and hold circuit means for receipt and storage of the output of said amplification means; second switching means connected between said amplification means and said plurality of sample and hold circuit means for selective connection of the output of said amplification means to a selected one of said sample and hold circuit as an input thereto; calibration coil means disposed in cooperative relationship with each of said plurality of superconductor means for inducing an opposing current therein; third switching means connecting said plurality of sample and hold circuit means and each of said calibration coil means for selective signal transfer therebetween, whereby the increased power signal is used to cancel out the superconducting electrical current flowing in a selected one of said superconductor sensor means; readout means for indicating the value of the signal stored in individual ones of said sample and store circuit means; fourth switching means connected between said plurality of sample and hold means and said readout means for providing selective connection between said readout means and a single one of said plurality of sample and hold means; and sequencer circuit means connected in circuit relationship with said first, second, third, and fourth switch means for synchronous operation thereof.
Claim 3
Dependent Claim
16 words
A magnetometer according to claim 1 in which said single transducer means comprises a Clark slug.
Claim 4
Dependent Claim
38 words
A magnetometer according to claim 1 in which said first switching means comprises thermal heater means placed in cooperative relation to said plurality of superconducting sensor means for selectively controlling the superconductivity of a portion of each thereof.
Claim 5
Dependent Claim
54 words
A magnetometer according to claim 3 further comprising diode network means electrically connected to the thermal heater means comprising said first switching means and effectively electrically connected to the aforesaid sequencer circuit means for control of the electrical current through said thermal heater means in response to an output of said sequencer circuit means.
Claim 6
Dependent Claim
33 words
A magnetometer according to claim 1 in which each of said sample and hold circuit means comprises an operational amplifier and a capacitor connected in parallel therewith, so as to perform integrating functions.
Claim 7
Dependent Claim
42 words
A magnetometer according to claim 5 further comprising fifth switching means connected in circuit with said operational amplifier and said capacitor, so as to selectively provide a discharge path for the electrical charge on said capacitor for providing an initial setting therefor.
Claim 8
Dependent Claim
31 words
A magnetometer according to claim 6 in which said fifth switching means is also electrically connected to the aforesaid first switching means for actuation thereof independently of said sequencer circuit means.
Claim 9
Dependent Claim
21 words
A magnetometer according to claim 1 in which said second, third, and fourth switching means comprise solid state controlled conduction devices.
Claim 10
Dependent Claim
18 words
A magnetometer according to claim 8 in which said solid state controlled conduction devices are field effect transistors.
Claim 11
Dependent Claim
80 words
A magnetometer according to claim 1 in which said sequencer circuit comprises in combination: clock circuit means for producing a series of timed pulses; logic circuit means connected to said clock circuit means so as to receive said timed pulses therefrom for establishing a predetermined pulse program in response thereto; and actuation circuit means connected to said logic circuit means so as to receive said pulse program therefrom for effecting control of said first, second, third, and fourth switching means.
References Cited (Backward Citations)
US3528005A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-05-30 | 1975-11-29 | 1976-05-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-05-30 | 1979-11-29 | 1980-05-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-05-30 | 1983-11-29 | 1984-05-30 | $7700.00 | Window Closed / Lapsed |