US4074343A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electric current chopper
Assignee: Bpifrance Financement SA
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Filing: 1976-10-20
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Granted: 1978-02-14
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Expires: 1996-10-20
Abstract
Abstract Apparatus for electrically chopping a direct current signal by controlling the superconductivity state of resistance elements contained within a cryostat. The resistance elements are in a bridge arrangement and the control is provided by laser diodes also contained within the cryostat.
Inventors
- 👤 Jacques Chaussy
- 👤 Jean-Louis Bret
- 👤 Adrien Berton
- 👤 Jacques Odin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 12:01
CPC Classifications
H; H10; H10N; H10N60/00; H10N60/80; H10N60/84; G; G01; G01R; G01R19/00; G01R19/18; Y; Y10; Y10S; Y10S505/00; Y10S505/825; Y10S505/867; Y10S505/868
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
54 words
An electric current chopper for use with a cryostat, comprising resistance means having at least one superconductivity resistance component adapted to be maintained in the cryostat slightly below its superconductivity threshold and a controlled electroluminescent diode placed inside the cryostat for periodically emitting a light beam for heating the resistance component above its threshold.
Claim 2
Dependent Claim
54 words
An electric current chopper for use with a cryostat, comprising resistance means having at least one superconductivity resistance component adapted to be maintained in the cryostat slightly below its superconductivity threshold and a controlled electroluminescent diode placed inside the cryostat for periodically emitting a light beam for heating the resistance component above its threshold.
Claim 3
Dependent Claim
15 words
A chopper in accordance with claim 1, wherein the diode is of the laser type.
Claim 4
Dependent Claim
36 words
A chopper in accordance with claim 1, wherein the resistance means includes a very thin insulation plate, the resistance component being arranged in a close zigzag pattern and being deposited on the very thin insulation plate.
Claim 5
Dependent Claim
16 words
A chopper in accordance with claim 3, wherein the resistance component is made of niobium carbo-nitride.
Claim 6
Dependent Claim
29 words
A chopper in accordance with claim 3, wherein the resistance component is made of a complex oxide of the type Li 0 .8 Ti 2 .2 O 4 .
Claim 7
Dependent Claim
55 words
A chopper in accordance with claim 1 wherein the resistance means includes an insulating plate and the resistance component is supported on the front side of the insulation plate and wherein a thermal mass is located within the cryostat against the reverse side of the insulating plate facing the resistance component to accelerate its cooling.
Claim 8
Dependent Claim
57 words
A chopper, in accordance with claim 3 wherein the resistance means further includes conductors connected to the resistance component at linking points and wherein a thermal mass is located against the reverse side of the insulating plate facing the linking points to maintain the temperature of these points and to avoid any phenomenon involving parasite thermo-electric voltage.
Claim 9
Dependent Claim
57 words
A chopper in accordance with claim 1 wherein the resistance means includes four components of resistance arranged in a bridge pattern, each of the pairs of components matching the opposite sides of the bridge and making up a set, and wherein two electroluminescent diodes are provided, each diode acting on a respective one of the two sets.
Claim 10
Dependent Claim
73 words
A chopper in accordance with claim 3, wherein the resistance means includes four resistance components arranged in sets, each set of two resistance components being arranged in the form of two sets of rectilinear zigzags in the shape of a comb with teeth not as wide as the spaces between them, said two sets being overlapping in such a manner that the teeth of one are placed in the spaces of the other.
Claim 11
Dependent Claim
23 words
A chopper in accordance with claim 6 wherein the thermal mass is in contact with and cooled by a wall of the cryostat.
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) | 1981-02-13 | 1981-08-15 | 1982-02-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-02-13 | 1985-08-15 | 1986-02-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-02-13 | 1989-08-15 | 1990-02-14 | $7700.00 | Window Closed / Lapsed |