US3597676A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Thermistor circuit for use in an angular movement sensing device
Assignee: Hercules LLC
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Filing: 1969-06-05
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Granted: 1971-08-03
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Expires: 1989-06-05
Abstract
Abstract A circuit for measuring the difference in cooling imposed upon two thermistors, which circuit is particularly adapted for use in a sensing device wherein a fluid jet is deflected relative to the thermistors in response to angular movement, and comprises a bridge for electrically heating each thermistor and thus lowering its resistance until the bridge is balanced, and a difference in the power consumption required to maintain each thermistor at its equilibrium temperature is an indication of the unequal cooling imposed upon the thermistors, which, in a fluid-jet-type angular rate sensor, is an indication of the deflection of the fluid jet from a centered condition relative to the jets which is in turn an indication of the rate and direction of angular movement.
Inventors
- 👤 Alvin G Moore
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 22:54
CPC Classifications
G; G01; G01P; G01P3/00; G01P3/26
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
184 words
A device for measuring the difference in the cooling imposed upon two thermistors comprising a bridge circuit for each of said thermistors with each thermistor connected between one of the bridge terminals and the output terminal in one leg of the respective bridge and heated by cUrrent in said leg of the bridge whereby the temperature and thus the resistance of the respective thermistor is varied upon changes in the cooling imposed thereon and the voltage at the bridge terminal in said one leg of the bridge is correspondingly varied, means for comparing the voltage at the bridge terminals of each bridge and for controlling the voltage applied at the input of said bridges in response to a voltage differential across said bridge terminals whereby the power supplied to the respective thermistor and thus its temperature and corresponding resistance is varied and the voltage at the respective bridge terminal is varied to establish equilibrium in said bridge, and means for comparing electrical values in the two bridges for producing an output signal proportional to the difference in the cooling imposed upon the two thermistors.
Claim 2
Independent Claim
184 words
A device for measuring the difference in the cooling imposed upon two thermistors comprising a bridge circuit for each of said thermistors with each thermistor connected between one of the bridge terminals and the output terminal in one leg of the respective bridge and heated by cUrrent in said leg of the bridge whereby the temperature and thus the resistance of the respective thermistor is varied upon changes in the cooling imposed thereon and the voltage at the bridge terminal in said one leg of the bridge is correspondingly varied, means for comparing the voltage at the bridge terminals of each bridge and for controlling the voltage applied at the input of said bridges in response to a voltage differential across said bridge terminals whereby the power supplied to the respective thermistor and thus its temperature and corresponding resistance is varied and the voltage at the respective bridge terminal is varied to establish equilibrium in said bridge, and means for comparing electrical values in the two bridges for producing an output signal proportional to the difference in the cooling imposed upon the two thermistors.
Claim 3
Dependent Claim
97 words
A device in accordance with claim 1 wherein the means for comparing the voltage at the bridge terminals of each bridge and for controlling the voltage applied at the input of said bridge in response to a voltage differential across said bridge terminals comprises a control transistor having the emitter thereof connected to the bridge terminal in the bridge leg including said thermistor and having the base thereof connected to the other bridge terminal, and means connected to and responsive to the voltage at the collector of said control transistor for varying the input to said bridge.
Claim 4
Dependent Claim
60 words
A device in accordance with claim 2 wherein the last mentioned means comprises a power transistor having the base thereof connected to the collector of said control transistor and to a source of power, the collector of said power transistor being connected to a source of power and the emitter thereof being connected to the input terminal of the bridge.
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) | 1974-08-02 | 1975-02-01 | 1975-08-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-08-02 | 1979-02-01 | 1979-08-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-08-02 | 1983-02-01 | 1983-08-03 | $7700.00 | Window Closed / Lapsed |