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US3772617A
Expired / Lapsed
US
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Method and arrangement for setting the remanent flux density in magnetic circuits and equalizer utilizing same
Assignee: AT&T Inc
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Filing: 1972-11-02
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Granted: 1973-11-13
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Expires: 1992-11-02
Abstract
Abstract The remanent flux density in a selected portion of a magnetic circuit is precisely set to a desired value by comparing the flux density in the selected portion to a predetermined reference, generating an error signal based on the comparison, integrating the error signal, and inducing an H field in the magnetic circuit in accordance with the integrated error signal. Integration of the error signal is performed only when the flux density has a substantially remanent value, i.e., only when the H field in the magnetic circuit is substantially zero. Thus, error in setting the flux density due to imperfect remanence in the magnetic circuit is substantially eliminated. In an illustrative embodiment of the invention, the magnetic circuit comprises a magnetic core having an air gap, and is advantageously employed in a transmission cable equalizer. The remanent flux density in the air gap is utilized to precisely set the resistance value of a magnetoresistor, which in turn determines the gain of the equalizer.
Inventors
- 👤 A Ciesielka
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 01:09
CPC Classifications
H; H04; H04B; H04B3/00; H04B3/02; H04B3/04
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
81 words
A method for setting the flux density in a selected portion of a magnetic circuit comprising the steps of, generating an error signal corresponding to the difference between the flux density in said selected portion and a desired value therefor, integrating said error signal, and inducing an H field in said circuit in accordance with the integrated error signal, characterized in that said integrating step is performed only when the flux density in said selected portion has substantially a remanent value.
Claim 2
Independent Claim
81 words
A method for setting the flux density in a selected portion of a magnetic circuit comprising the steps of, generating an error signal corresponding to the difference between the flux density in said selected portion and a desired value therefor, integrating said error signal, and inducing an H field in said circuit in accordance with the integrated error signal, characterized in that said integrating step is performed only when the flux density in said selected portion has substantially a remanent value.
Claim 3
Dependent Claim
18 words
A method in accordance with claim 1 wherein said integrating and inducing steps are performed independently in sequence.
Claim 4
Dependent Claim
64 words
A method in accordance with claim 2 wherein said generating step comprises the steps of, sensing the flux density in said selected portion, providing a control signal having an amplitude proportional to the sensed flux density, providing a reference signal corresponding to said desired flux density value, and determining the difference between said control signal and said reference signal to generate said error signal.
Claim 5
Dependent Claim
30 words
A method in accordance with claim 3 wherein said selected portion is an air gap and wherein said sensing step is performed using a magnetoresistor positioned in said air gap.
Claim 6
Dependent Claim
54 words
A method in accordance with claim 4 wherein said control signal providing step comprises the steps of extending a predetermined signal to the input of an amplifier and adjusting tHe gain of said amplifier based on the resistance value of said magnetoresistor, said control signal being derived from the output signal of said amplifier.
Claim 7
Dependent Claim
88 words
An arrangement for setting the flux density in a selected portion of a magnetic circuit comprising, means for generating an error signal corresponding to the difference between the flux density in said selected portion and a desired value therefor, means operative for integrating said error signal, and means operative for inducing an H field in said magnetic circuit in accordance with the integrated error signal, the improvement comprising means for operating said integrating means only when the flux density in said selected portion has substantially a remanent value.
Claim 8
Dependent Claim
88 words
An arrangement for setting the flux density in a selected portion of a magnetic circuit comprising, means for generating an error signal corresponding to the difference between the flux density in said selected portion and a desired value therefor, means operative for integrating said error signal, and means operative for inducing an H field in said magnetic circuit in accordance with the integrated error signal, the improvement comprising means for operating said integrating means only when the flux density in said selected portion has substantially a remanent value.
Claim 9
Dependent Claim
25 words
An arrangement in accordance with claim 6 wherein said last-mentioned means comprises means for operating said integrating means and said inducing means independently in sequence.
Claim 10
Dependent Claim
69 words
An arrangement in accordance with claim 7 wherein said generating means comprises means for sensing the flux density in said selected portion, means for providing a control signal having an amplitude proportional to the sensed flux density, means for providing a reference signal corresponding to said desired flux density value, and means for determining the difference between said control signal and said reference signal to generate said error signal.
Claim 11
Dependent Claim
28 words
An arrangement in accordance with claim 8 wherein said selected portion is an air gap and wherein said sensing means includes a magnetoresistor positioned in said air gap.
Claim 12
Dependent Claim
57 words
An arrangement in accordance with claim 9 wherein said control signal providing means comprises an amplifier, means for extending a predetermined signal to the input of said amplifier and means for adjusting the gain of said amplifier in accordance with the resistance value of said magnetoresistor, said control signal being derived from the output of said amplifier.
Claim 13
Dependent Claim
153 words
In an equalizer including circuit means adapted for insertion into a transmission path and operative for varying the gain of said path the combination comprising, a magnetic core having an air gap interrupting its continuity and providing remanent magnetic flux in said air gap, means for operating said circuit means in accordance with the density of magnetic flux in said air gap, means coupled to said circuit means for detecting a pilot signal applied to said path, means for comparing the detected pilot signal to a predetermined reference signal and for generating an error signal based on the comparison, means operative for integrating said error signal only when the flux density in said gap has substantially a remanent value, and means operative for applying a magnetic field to said core to adjust the density of the flux in said air gap, said magnetic field being proportional to the output of said integrating means.
Claim 14
Dependent Claim
153 words
In an equalizer including circuit means adapted for insertion into a transmission path and operative for varying the gain of said path the combination comprising, a magnetic core having an air gap interrupting its continuity and providing remanent magnetic flux in said air gap, means for operating said circuit means in accordance with the density of magnetic flux in said air gap, means coupled to said circuit means for detecting a pilot signal applied to said path, means for comparing the detected pilot signal to a predetermined reference signal and for generating an error signal based on the comparison, means operative for integrating said error signal only when the flux density in said gap has substantially a remanent value, and means operative for applying a magnetic field to said core to adjust the density of the flux in said air gap, said magnetic field being proportional to the output of said integrating means.
Claim 15
Dependent Claim
25 words
An equalizer in accordance with claim 11 wherein said last-mentioned means comprises means for operating said integrating means and said applying means independently in sequence.
Claim 16
Dependent Claim
23 words
An equalizer in accordance with claim 12 wherein said means for operating said circuit means includes magnetoresistive means positioned in said air gap.
Claim 17
Dependent Claim
44 words
An equalizer in accordance with claim 13 wherein said detecting means includes means for providing a d.c. control signal proportional to said detected pilot signal and where said comparing means includes means for determining the difference between said control signal and said error signal.
Claim 18
Dependent Claim
30 words
An equalizer in accordance with claim 14 further comprising means for amplifying the output of said integrating means, said magnetic field being proportional to the output of said amplifying means.
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) | 1976-11-12 | 1977-05-14 | 1977-11-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-11-12 | 1981-05-14 | 1981-11-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-11-12 | 1985-05-14 | 1985-11-13 | $7700.00 | Window Closed / Lapsed |