Patent EP0238089A2 successfully refreshed from Google Patents.
US3609541A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Radio frequency coaxial ammeter with thermal compensation
Assignee: Individual
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Filing: 1970-01-20
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Granted: 1971-09-28
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Expires: 1990-01-20
Abstract
Abstract A cylindrical reflector, having an inner elliptical reflecting surface, is positioned in a coaxial line. A thin-film heater is connected to the center conductor of the line. The heater is located along one focal axis of the reflecting surface and the hot junctions of a thermopile are located along the other focal axis. Input current causes the heater to radiate infrared energy which is reflected and focused onto both sides of the hot junctions. The resulting electrical output of the thermopile is proportional to radiated power and consequently input current squared, and because of thermal compensation the output is substantially independent of ambient and self-heating temperature changes.
Inventors
- 👤 Winston W Scott Jr
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 16:56
CPC Classifications
G; G01; G01R; G01R21/00; G01R21/10; G01R21/12; G01R19/00; G01R19/32
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
221 words
A radio frequency coaxial ammeter comprising: a cylindrical reflector made of electrical and thermal conductive material and having an inner elliptical reflective surface delineated by a first and second focal axis, a first and second coaxial line connected to said cylinder, and having outer conductors made of electrical and conductive material and a first and second cylindrical support arm, respectively, as their center conductors, said first and second support arm, each including a substrate of electrical insulating and thermal conductive material, and each having a metallized outer surface, a cylindrical heater including a substrate made of electrical and thermal insulator material and having a metallized outer surface, means for positioning said heater approximately along the first focal axis and between the first and second support arms in such a way that the outer surface of said heater is in electrical conductive relationship with the outer surfaces said first and second support arm, a thermopile having a plurality of thermal elements connected in electrical series and thermal parallel, each thermal element having a hot junction and cold junction, means for positioning said thermopile so that the hot junctions are located approximately along the second focal axis and the cold junctions are placed in thermal conductive relationship with said reflector, and a direct current detection instrument connected across the output of said thermopile.
Claim 2
Dependent Claim
221 words
A radio frequency coaxial ammeter comprising: a cylindrical reflector made of electrical and thermal conductive material and having an inner elliptical reflective surface delineated by a first and second focal axis, a first and second coaxial line connected to said cylinder, and having outer conductors made of electrical and conductive material and a first and second cylindrical support arm, respectively, as their center conductors, said first and second support arm, each including a substrate of electrical insulating and thermal conductive material, and each having a metallized outer surface, a cylindrical heater including a substrate made of electrical and thermal insulator material and having a metallized outer surface, means for positioning said heater approximately along the first focal axis and between the first and second support arms in such a way that the outer surface of said heater is in electrical conductive relationship with the outer surfaces said first and second support arm, a thermopile having a plurality of thermal elements connected in electrical series and thermal parallel, each thermal element having a hot junction and cold junction, means for positioning said thermopile so that the hot junctions are located approximately along the second focal axis and the cold junctions are placed in thermal conductive relationship with said reflector, and a direct current detection instrument connected across the output of said thermopile.
Claim 3
Dependent Claim
32 words
The coaxial ammeter set forth in claim 1 including: thermal conductive and electrical insulating connecting means for placing said first and second support arm in thermal conductive relationship with said cylindrical reflector.
Claim 4
Dependent Claim
56 words
The coaxial ammeter set forth in claim 2, wherein: said connecting means comprises a first and second bead, each formed of electrical insulating and thermal conductive material, a first coaxial connector having a center conductor connected to said first support arm, and a second coaxial connector having a center conductor connected to said second support arm.
Claim 5
Dependent Claim
137 words
The coaxial ammeter set forth in claim 3 wherein: the end surfaces of said first and second support arm and said heater are metallized, a first and second washer, each made of electrical and conductive material, said first washer being positioned between one end of the center conductor of said first connector and one end of said first support arm, said second washer being positioned between the other end of said first support arm and one end of said heater, a third and fourth washer, each made of electrical and conductive material, said third washer being positioned between one end of the center conductor said second connector and one end of said second support arm, and said fourth washer being positioned between the other end of said second support arm and the otHer end of said heater.
Claim 6
Dependent Claim
68 words
The coaxial ammeter set forth in claim 1 wherein said thermopile comprises: a frame constructed of electrical and thermal insulator material, a plurality of thermal elements, each including a hot and cold junction, connected in electrical series and thermal parallel, said thermal elements being positioned on said frame in such a way that radiant energy reflected from said reflecting surface falls on both sides of the hot junctions.
Claim 7
Dependent Claim
19 words
The coaxial ammeter set forth in claim 1 wherein: said hot junctions are coated with an energy absorbing material.
Claim 8
Dependent Claim
23 words
The coaxial ammeter set forth in claim 1 wherein the outer metallized surface of said heater comprises: a thin film of resistive material.
Claim 9
Dependent Claim
61 words
The coaxial ammeter set forth in claim 1 wherein: the first and second support arms each include a step change in its diameter located relative to the cylindrical elliptical outer conduct transitions, whereby substantially reflectionless transitions are obtained from said first coaxial line to the elliptical line that includes the heater and the reflector and then to said second coaxial line.
Claim 10
Dependent Claim
74 words
The coaxial ammeter set forth in claim 1 wherein: the end surfaces of said first and second support arm and said heater are metallized, a first washer made of electrical and conductive material positioned between one end of said heater and one end of said first support arm, and a second washer made of electrical and conductive material positioned between the other end of said heater and one end of said second support arm.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-09-27 | 1975-03-29 | 1975-09-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-09-27 | 1979-03-29 | 1979-09-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-09-27 | 1983-03-29 | 1983-09-28 | $7700.00 | Window Closed / Lapsed |