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Patent US3835313A successfully refreshed from Google Patents.
US3835313A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Arrangement for compensating for changes in the operating characteristics of a measuring element
Assignee: Individual
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Filing: 1973-04-10
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Granted: 1974-09-10
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Expires: 1993-04-10
Abstract
Abstract A photoresistor forms part of a voltage divider whose tap is connected to the inverting input of a differential amplifier. A second voltage divider has a tap connected to the direct input of the differential amplifier. The differential amplifier output is connected to a capacitor through a parallel resistor-capacitor network. The voltage across the capacitor consitutes the emitterbase voltage of a transistor whose emitter-collector circuit is connected in parallel with one resistor of the second voltage divider. Changes in the operating characteristic of the measuring element cause a change in the voltage across the capacitor which in turn causes a change in the resistance of the emittercollector circuit of the transistor in such a direction that the output voltage of the differential amplifier is independent of the changes of the operating characteristics of the measuring element.
Inventors
- 👤 G Stiefelmeyer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 21:53
CPC Classifications
G; G01; G01R; G01R17/00; G01R17/10; G01R17/105; G01B; G01B11/00; G01B11/08; G01B11/10; G01B11/105; G01D; G01D3/00; G01D3/028; G01D3/032; G05; G05B; G05B1/00; G05B1/01; G05B1/02
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
203 words
In a measuring arrangement having a measuring means having an operating characteristic for furnishing a predetermined output in response to a predetermined input, a system for compensating for internally or externally caused changes in said operating characteristic with resulting substantially steady state changes in said output comprising, in combination, means for furnishing a reference signal; differential amplifier means having a first input connected to said measuring means, a second input connected to said means for furnishing a reference signal and a differential amplifier output for furnishing a differential output signal corresponding to the difference between signals furnished at said first and second inputs; RC circuit means including a capacitor, connected to said differential amplifier output for furnishing a drift signal corresponding to said substantially steady state change in said predetermined output resulting from said change in said operating characteristic of said measuring means; and control circuit means having an input connected to said capacitor means and and output connected to said second input of said differential amplifier means, for varying said reference signal as a function of said drift signal, in such a manner that said differential amplifier output signal is independent of said changes in said operating characteristic of said measuring means.
Claim 2
Dependent Claim
203 words
In a measuring arrangement having a measuring means having an operating characteristic for furnishing a predetermined output in response to a predetermined input, a system for compensating for internally or externally caused changes in said operating characteristic with resulting substantially steady state changes in said output comprising, in combination, means for furnishing a reference signal; differential amplifier means having a first input connected to said measuring means, a second input connected to said means for furnishing a reference signal and a differential amplifier output for furnishing a differential output signal corresponding to the difference between signals furnished at said first and second inputs; RC circuit means including a capacitor, connected to said differential amplifier output for furnishing a drift signal corresponding to said substantially steady state change in said predetermined output resulting from said change in said operating characteristic of said measuring means; and control circuit means having an input connected to said capacitor means and and output connected to said second input of said differential amplifier means, for varying said reference signal as a function of said drift signal, in such a manner that said differential amplifier output signal is independent of said changes in said operating characteristic of said measuring means.
Claim 3
Dependent Claim
55 words
An arrangement as set forth in claim 1, wherein said control circuit means comprise a transistor having a base connected to said capacitor and an emitter-collector circuit connected to said means for furnishing a reference signal in such a manner that said reference signal varies as a function of the resistance of said emitter-collector circuit.
Claim 4
Dependent Claim
33 words
An arrangement as set forth in claim 1, wherein said RC circuit means comprise a resistor connected in series to said capacitor; further comprising an additional capacitor connected in parallel with said resistor.
Claim 5
Dependent Claim
17 words
An arrangement as set forth in claim 1, wherein said control circuit means comprise a Darlington circuit.
Claim 6
Dependent Claim
84 words
An arrangement as set forth in claim 2 wherein said emitter-collector circuit of said transistor is blocked when said drift signal is a predetermined drift signal indicative of maximum allowable drift; and wherein said differential amplifier output signal exceeds a predetermined differential amplifier output signal when said emitter-collector circuit of said transistor is blocked; and further comprising threshold circuit means connected to said differential amplifier output for furnishing an indicator signal when said differential amplifier output signal exceeds said predetermined differential amplifier output signal.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-09-09 | 1978-03-11 | 1978-09-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-09-09 | 1982-03-11 | 1982-09-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-09-09 | 1986-03-11 | 1986-09-10 | $7700.00 | Window Closed / Lapsed |