US4835747A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Compensating sensor device for a charge amplifier circuit used in piezoelectric hydrophones
Assignee: Thales SA
•
Filing: 1988-04-11
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Granted: 1989-05-30
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Expires: 2008-04-11
Abstract
Abstract To compensate for the effect of external parameters on piezoelectric sensors connected to a charge amplifier, a small portion of this sensor is used to form the feedback capacitor of the amplifier. These parameters then have the same effect on the sensor and on the capacitor, thus making it possible to provide compensation to hydrophones made of piezoelectric polymer material.
Inventors
- 👤 Daniel Billet
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 22:53
CPC Classifications
G; G01; G01H; G01H11/00; G01H11/06; G01H11/08; G01S; G01S1/00; G01S1/72; Y; Y10; Y10S; Y10S310/00; Y10S310/80
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
156 words
A compensating device for a charge amplifier circuit used in piezoelectric hydrophones comprising: a first insulating piezoelectric layer having a first side and a second side; a first external conducting electrode and a second external conducting electrode, said first electrode interfaced with the first side of said first insulating piezoelectric layer and said second electrode covering the second side of said piezoelectric layer such that a capacitor is formed; a differential operational amplifier having an output, a negative input and a positive input, the first and the second external electrodes being connected to the positive input of said differential amplifier; a feedback capacitor connected to the output of said differential operational amplifier; said feedback capacitor comprising a first isolated portion of said first external conducting electrode and a second isolated portion of said second external conducting electrode, said first isolated portion and said second isolated portion being connected to the output of said differential operational amplifier.
Claim 2
Dependent Claim
156 words
A compensating device for a charge amplifier circuit used in piezoelectric hydrophones comprising: a first insulating piezoelectric layer having a first side and a second side; a first external conducting electrode and a second external conducting electrode, said first electrode interfaced with the first side of said first insulating piezoelectric layer and said second electrode covering the second side of said piezoelectric layer such that a capacitor is formed; a differential operational amplifier having an output, a negative input and a positive input, the first and the second external electrodes being connected to the positive input of said differential amplifier; a feedback capacitor connected to the output of said differential operational amplifier; said feedback capacitor comprising a first isolated portion of said first external conducting electrode and a second isolated portion of said second external conducting electrode, said first isolated portion and said second isolated portion being connected to the output of said differential operational amplifier.
Claim 3
Dependent Claim
32 words
A compensating sensor device according to claim 11, wherein: said first isolated portion is centered on said first piezoelectric layer and said second isolated portion is centered on said second piezoelectric layer.
Claim 4
Dependent Claim
17 words
A compensating sensor device according to claim 1, wherein: said first piezoelectric layer is cylindrical and hollow.
Claim 5
Dependent Claim
17 words
A compensating sensor device according to claim 1, wherein: said first piezoelectric layer has a rectangular shape.
Claim 6
Dependent Claim
19 words
A compensating sensor device according to claim 1, wherein: said first piezoelectric layer is made of a piezoelectric polymer.
Claim 7
Dependent Claim
61 words
A compensating sensor device according to claim 1, further comprising: a second insulating piezoelectric layer; a central electrode sandwiched between the first piezoelectric layer and the second piezoelectric layer, said second external electrode being interfaced with said second piezoelectric layer; said first isolated portion and said second isolated portion being connected in parallel and positioned in a face to face manner.
Claim 8
Dependent Claim
21 words
A compensating sensor according to claim 6, wherein: said first external electrode and said second external electrode are connected in parallel.
Claim 9
Dependent Claim
22 words
A compensating sensor according to claim 7, wherein: said central electrode is connected to the negative input of said differential operational amplifier.
Claim 10
Dependent Claim
27 words
A compensating sensor according to claim 6, wherein: a surface area of said first isolated portion and a surface area of said second isolated portion are identical.
Claim 11
Dependent Claim
32 words
A compensating sensor according to claim 9, wherein: the surface area of said first isolated portion and the surface area of the second isolated portion determine the capacitance of said feedback capacitor.
References Cited (Backward Citations)
US3659123A
Cited
FR2314506A1
Cited
US4149102A
Cited
US4517665A
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US4451710A
Cited
US4695988A
Cited
US4709360A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-05-29 | 1992-11-28 | 1993-05-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-05-29 | 1996-11-28 | 1997-05-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-05-29 | 2000-11-28 | 2001-05-30 | $7700.00 | Window Closed / Lapsed |