US4356728A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Device for measuring the level of a liquid
Assignee: E D VEGLIA
•
Filing: 1980-05-15
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Granted: 1982-11-02
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Expires: 2000-05-15
Abstract
Abstract A device for measuring the level of a liquid, comprising a high temperature coefficient sensor immersed in the liquid, a detection circuit connected to the sensor for delivering a voltage indicative of the level of liquid, a memory circuit to which said voltage is applied, a saw-tooth signal generator circuit and, a comparator. The output signals of the memory circuit and of the saw-tooth signal circuit are coupled to input terminals of the comparator, and a display galvanometer is connected to the output of said comparator.
Inventors
- 👤 Michel Gomez
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 18:25
CPC Classifications
G; G01; G01F; G01F23/00; G01F23/22; G01F23/24; G01F23/246; F; F01; F01M; F01M11/00; F01M11/10; F01M11/12
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
180 words
A device for measuring the level of a liquid in a tank comprising a high temperature coefficient sensor immersed in the liquid, a circuit for generating a constant current and connected to the output of the sensor for delivering a voltage indicative of the resistance of the sensor, means for activating cyclically said circuit, a temperature compensating circuit comprising a first comparator to which said voltage is applied and first capacitor connected to the output of said first comparator, the output of said compensating circuit delivering a compensated voltage indicative of the level of the liquid irrespective of the initial liquid and ambient temperature, a memory circuit comprising a second comparator having one input connected to earth and receiving said compensated voltage on the other input and a second capacitor connected to the output of said second comparator, a circuit for generating a saw-tooth signal, a third comparator, the output signal of the memory circuit and the saw-tooth signal circuit being applied to the inputs of said third comparator, and a galvanometer connected to the output of said third comparator.
Claim 2
Independent Claim
180 words
A device for measuring the level of a liquid in a tank comprising a high temperature coefficient sensor immersed in the liquid, a circuit for generating a constant current and connected to the output of the sensor for delivering a voltage indicative of the resistance of the sensor, means for activating cyclically said circuit, a temperature compensating circuit comprising a first comparator to which said voltage is applied and first capacitor connected to the output of said first comparator, the output of said compensating circuit delivering a compensated voltage indicative of the level of the liquid irrespective of the initial liquid and ambient temperature, a memory circuit comprising a second comparator having one input connected to earth and receiving said compensated voltage on the other input and a second capacitor connected to the output of said second comparator, a circuit for generating a saw-tooth signal, a third comparator, the output signal of the memory circuit and the saw-tooth signal circuit being applied to the inputs of said third comparator, and a galvanometer connected to the output of said third comparator.
Claim 3
Dependent Claim
26 words
A device as claimed in claim 1, comprising resistance and capacitor means connected between said second and said third comparators for cyclically recharging said second capacitor.
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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) | 1985-11-01 | 1986-05-03 | 1986-11-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-11-01 | 1990-05-03 | 1990-11-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-11-01 | 1994-05-03 | 1994-11-02 | $7700.00 | Window Closed / Lapsed |