Patent US3603768A successfully refreshed from Google Patents.
US3603768A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Thin-film resistor adjustment
Assignee: Bunker Ramo Corp
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Filing: 1969-05-26
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Granted: 1971-09-07
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Expires: 1989-05-26
Abstract
Abstract An apparatus for adjusting the resistance values and temperature coefficients of resistance of thin-film resistors within very close tolerances. The adjustment is achieved through heating of the thin-film resistors to a very high temperature for very short periods of time.
Inventors
- 👤 John W Ireland
- 👤 James C Holloway
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 12:38
CPC Classifications
H; H01; H01C; H01C17/00; H01C17/22; H01C17/26; H01C17/265; H01C17/267
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
120 words
ApparaTus for automatically adjusting the impedance value of a heat-adjustable impedance, said apparatus comprising in combination: impedance bridge means to which said heat-adjustable impedance is electrically connected so as to permit Measurement of the impedance thereof power source means for energizing said bridge means and for heating said heat-adjustable impedance so as to cause its impedance value to vary in a predetermined manner, detector means coupled to said bridge means for detecting when said heat-adjustable impedance reaches a desired predetermined value and for providing an output indication in response thereto, and means coupled to said power source means and to said detector means for terminating the heating of said heat-adjustable impedance in response to the occurrence of said output indication.
Claim 2
Dependent Claim
120 words
ApparaTus for automatically adjusting the impedance value of a heat-adjustable impedance, said apparatus comprising in combination: impedance bridge means to which said heat-adjustable impedance is electrically connected so as to permit Measurement of the impedance thereof power source means for energizing said bridge means and for heating said heat-adjustable impedance so as to cause its impedance value to vary in a predetermined manner, detector means coupled to said bridge means for detecting when said heat-adjustable impedance reaches a desired predetermined value and for providing an output indication in response thereto, and means coupled to said power source means and to said detector means for terminating the heating of said heat-adjustable impedance in response to the occurrence of said output indication.
Claim 3
Dependent Claim
35 words
The invention in accordance with claim 1, wherein said heat-adjustable impedance is a thin-film resistor supported on a substrate, and wherein said apparatus includes electrical probes for electrically connecting said resistor to said bridge means.
Claim 4
Dependent Claim
21 words
The invention in accordance with claim 2, wherein said apparatus includes means for heating said substrate during adjustment of said resistor.
Claim 5
Dependent Claim
34 words
The invention in accordance with claim 2, wherein the heating of said resistor is obtained as a result of the current flowing therein when said bridge means is energized by said power source means.
Claim 6
Dependent Claim
22 words
The invention in accordance with claim 4, wherein the heating of said resistor is terminated by interrupting the flow of current therein.
Claim 7
Dependent Claim
20 words
The invention in accordance with claim 5, wherein said power source means supplies an alternating current to said bridge means.
Claim 8
Dependent Claim
41 words
The invention in accordance with claim 5, wherein said apparatus includes means for selectively energizing and deenergizing said bridge means, and wherein the deenergizing of said bridge means is caused to occur in response to the occurrence of said output indication.
Claim 9
Dependent Claim
57 words
The invention in accordance with claim 2, wherein said apparatus is constructed and arranged for automatically adjusting the resistance value of each of a plurality of heat-adjustable thin-film resistors supported on a common substrate, and wherein said apparatus includes automatically operating switch means for successively connecting each of said resistors to said bridge means for adjustment thereof.
Claim 10
Dependent Claim
40 words
The invention in accordance with claim 8, wherein the heating of each resistor when connected to said bridge means is obtained as a result of the current flowing therein when said bridge means is energized by said power source means.
Claim 11
Dependent Claim
22 words
The invention in accordance with claim 9, wherein said apparatus also includes means for heating said substrate during adjustment of said resistors.
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) | 1974-09-06 | 1975-03-08 | 1975-09-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-09-06 | 1979-03-08 | 1979-09-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-09-06 | 1983-03-08 | 1983-09-07 | $7700.00 | Window Closed / Lapsed |