Patent US3654545A successfully refreshed from Google Patents.
US3654545A
Expired / Lapsed
US
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Semiconductor strain gauge amplifier
Assignee: Honeywell Inc
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Filing: 1970-08-11
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Granted: 1972-04-04
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Expires: 1990-08-11
Abstract
Abstract A semiconductor strain gauge amplifier apparatus having a temperature compensated bridge circuit for neutralizing the adverse affect of the ambient temperature variations upon the initial offset, sensitivity and span of the bridge, and thereby, providing temperature compensation over a wide range of operating temperatures.
Inventors
- 👤 Anthony M Demark
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 04:41
CPC Classifications
G; G01; G01L; G01L1/00; G01L1/20; G01L1/22; G01L1/2268; G01L1/2281
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
131 words
An impedance bridge circuit having a first leg including a first and second serially connected condition responsive arm; a second leg including a first and second serially connected condition responsive arm; said bridge having input means and output means including input terminals, and output terminals, respectively; current control means connected to said input terminals for controlling the flow of electric current through said bridge legs; current sensing means for sensing the sum of currents flowing in said first and second legs; said current control means including current regulating means responsive to said current sensing means for maintaining the sum of said currents at a predetermined level; and means for concurrently controlling the current flow through each of said legs individually; and output means connected to said output terminals of said bridge.
Claim 2
Dependent Claim
131 words
An impedance bridge circuit having a first leg including a first and second serially connected condition responsive arm; a second leg including a first and second serially connected condition responsive arm; said bridge having input means and output means including input terminals, and output terminals, respectively; current control means connected to said input terminals for controlling the flow of electric current through said bridge legs; current sensing means for sensing the sum of currents flowing in said first and second legs; said current control means including current regulating means responsive to said current sensing means for maintaining the sum of said currents at a predetermined level; and means for concurrently controlling the current flow through each of said legs individually; and output means connected to said output terminals of said bridge.
Claim 3
Dependent Claim
56 words
The invention as set forth in Claim 1 wherein said current sensing means includes a resistor connected in series between an input terminal of said bridge and a point of reference potential, said current sensing means further including temperature responsive means connected in shunt with said resistor whereby to compensate said bridge for thermally induced changes.
Claim 4
Dependent Claim
41 words
The invention as set forth in Claim 1 wherein said means for controlling the current flow through each of said legs individually includes feedback means connected between said output means and an input terminal of at least one of said legs.
Claim 5
Dependent Claim
71 words
The invention as set forth in Claim 1 wherein said input terminals of said bridge includes one input terminal common to both of said legs at one end thereof and a pair of input terminals individual to each of said legs at the other ends thereof, said means for controlling the current flow through each of said legs individually being connected to said pair of input terminals and said output means.
Claim 6
Dependent Claim
28 words
The invention as set forth in Claim 4 and including further temperature compensating means in each of said legs to compensate said bridge for thermally induced zero shift.
Claim 7
Dependent Claim
66 words
The invention as set forth in Claim 4 wherein said output means includes a transistor amplifier connected to control the amount of current flowing in a pair of transmission lines, which transmission lines carry all of the electrical energy for energizing said impedance bridge circuit, said current in said transmission lines being a function of the condition sensed by said condition responsive arms of said bridge.
Claim 8
Dependent Claim
19 words
The invention as set forth in Claim 6 wherein said condition responsive arms comprise strain sensitive semiconductor resistance elements.
References Cited (Backward Citations)
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US3457493A
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US3517556A
Cited
US3495159A
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US3503261A
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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) | 1975-04-04 | 1975-10-04 | 1976-04-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-04-04 | 1979-10-04 | 1980-04-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-04-04 | 1983-10-04 | 1984-04-04 | $7700.00 | Window Closed / Lapsed |