US3778759A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Static filter for long line data systems
Assignee: Halliburton Co
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Filing: 1971-12-27
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Granted: 1973-12-11
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Expires: 1991-12-27
Abstract
Abstract A data system having data communication over a pair of electrical conductors includes a filter for eliminating static noise of atmospheric origin. In a specific embodiment, a system for acquiring seismic data includes a static filter for attenuating a common mode signal and atmospheric noise while preserving desired difference mode data. A specific embodiment of the filter includes a pair of input inductors having a piar of series connected capacitors and a pair of series connected resistors in parallel and connected across the conductors, with the nodes between the two capacitors and two resistors being connected to a common reference potential. The inductors are wound on the same core to effectively cancel the inductance presented to the difference mode signal.
Inventors
- 👤 P Carroll
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 15:54
CPC Classifications
H; H04; H04L; H04L25/00; H04L25/02; H04L25/08; H04L25/085
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
164 words
In a system for acquiring seismic data of the type wherein at least one seismic transducer is responsive to a seismic disturbance to produce a difference mode electrical signal to be coupled by a pair of wire lines to a seismic data acquisition system, and wherein a common mode signal may be picked up by said lines from atmospheric disturbances, filter means coupled between said seismic transducer and said data acquisition system for attenuating said common mode signal and noise without significantly attenuating said difference mode signal, wherein said filter means is comprised as follows: a. a pair of magnetically coupled input inductors one connected to each wire line; b. following said inductors a pair of series connected capacitors connected across said wire lines; c. a pair of series connected resistors connected across said wire lines in parallel with said pair of capacitors; and d. means for connecting a node between said capacitors and a node between said resistors to a common reference potential.
Claim 2
Dependent Claim
164 words
In a system for acquiring seismic data of the type wherein at least one seismic transducer is responsive to a seismic disturbance to produce a difference mode electrical signal to be coupled by a pair of wire lines to a seismic data acquisition system, and wherein a common mode signal may be picked up by said lines from atmospheric disturbances, filter means coupled between said seismic transducer and said data acquisition system for attenuating said common mode signal and noise without significantly attenuating said difference mode signal, wherein said filter means is comprised as follows: a. a pair of magnetically coupled input inductors one connected to each wire line; b. following said inductors a pair of series connected capacitors connected across said wire lines; c. a pair of series connected resistors connected across said wire lines in parallel with said pair of capacitors; and d. means for connecting a node between said capacitors and a node between said resistors to a common reference potential.
Claim 3
Dependent Claim
16 words
The system of claim 1 wherein said pair of inductors are wound on the same core.
Claim 4
Dependent Claim
25 words
The system of claim 1 wherein said inductors are of equal inductance, said capacitors are of equal capacitance and said resistors are of equal resistance.
Claim 5
Dependent Claim
94 words
The system of claim 1 wherein said filter means is a multi-channel filter comprised as follows: a. a plurality of magnetically coupled inductors, one series connected with each wire line in said cable; b. following said inductors, a pair of series connected capacitors connected across each pair of wire lines; c. a pair of series connected resistors connected across each pair of wire lines in parallel with said capacitors; and d. means for connecting a node between each pair of capacitors and a node between each pair of resistors to a common reference potential.
Claim 6
Dependent Claim
16 words
The system of claim 4 wherein all of said inductors are wound on the same core.
Claim 7
Dependent Claim
31 words
The system of claim 4 wherein all of said inductors are of equal inductance, all of said capacitors are of equal capacitance and all of said resistors are of equal resistance.
Claim 8
Dependent Claim
108 words
A filter for use in attenuating common mode signals carried by pairs of electrical conductors in a multi-conductor cable, comprising: a. a plurality of magnetically coupled inductors, one connected to each electrical conductor; b. a plurality of pairs of series connected capacitors, one pair electrically connected across each pair of electrical conductors subsequent to said inductors; c. a plurality of pairs of series connected resistors, one pair electrically connected across each pair of electrical conductors and in parallel with a pair of capacitors; and d. means for connecting a node between each pair of capacitors and a node between each pair of resistors to a common reference potential.
Claim 9
Dependent Claim
108 words
A filter for use in attenuating common mode signals carried by pairs of electrical conductors in a multi-conductor cable, comprising: a. a plurality of magnetically coupled inductors, one connected to each electrical conductor; b. a plurality of pairs of series connected capacitors, one pair electrically connected across each pair of electrical conductors subsequent to said inductors; c. a plurality of pairs of series connected resistors, one pair electrically connected across each pair of electrical conductors and in parallel with a pair of capacitors; and d. means for connecting a node between each pair of capacitors and a node between each pair of resistors to a common reference potential.
Claim 10
Dependent Claim
25 words
The filter of claim 7 wherein said inductors are of eqUal inductance, said capacitors are of equal capacitance, and said resistors are of equal resistance.
Claim 11
Dependent Claim
16 words
The filter of claim 8 wherein all of said inductors are wound on a common core.
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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) | 1976-12-10 | 1977-06-11 | 1977-12-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-12-10 | 1981-06-11 | 1981-12-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-12-10 | 1985-06-11 | 1985-12-11 | $7700.00 | Window Closed / Lapsed |