US4053716A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Switching network with a crosstalk elimination capability
Assignee: NEC Corp
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Filing: 1976-07-26
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Granted: 1977-10-11
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Expires: 1996-07-26
Abstract
Abstract A switching network having particular application in telephone exchanges is provided with crosstalk elimination capability. The crosstalk is effectively cancelled by generating signals which are reverse in phase to the crosstalk signals and adding these generated signals to the crosstalk signals.
Inventors
- 👤 Osamu Enomoto
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 23:44
CPC Classifications
H; H04; H04Q; H04Q3/00; H04Q3/42; H04Q3/52; H04Q3/521
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
140 words
A switching network with crosstalk elimination capability comprising: a group of incoming lines connected to subscribers; a group of outgoing lines intersecting said incoming line group; a plurality of switching elements provided at preselected crosspoints formed between said incoming lines and said outgoing lines for interconnecting a desired incoming line and a desired outgoing line in response to a call from a subscriber; a plurality of transformers each having a primary winding connected to a selected incoming or outgoing line and at least a first secondary winding for generating a signal reverse in phase to that supplied to the primary winding; and a plurality of first capacitors each having one end connected to each said first secondary winding of the transformers and the other end connected to an incoming or outgoing line adjacent to the selected incoming or outgoing line.
Claim 2
Dependent Claim
140 words
A switching network with crosstalk elimination capability comprising: a group of incoming lines connected to subscribers; a group of outgoing lines intersecting said incoming line group; a plurality of switching elements provided at preselected crosspoints formed between said incoming lines and said outgoing lines for interconnecting a desired incoming line and a desired outgoing line in response to a call from a subscriber; a plurality of transformers each having a primary winding connected to a selected incoming or outgoing line and at least a first secondary winding for generating a signal reverse in phase to that supplied to the primary winding; and a plurality of first capacitors each having one end connected to each said first secondary winding of the transformers and the other end connected to an incoming or outgoing line adjacent to the selected incoming or outgoing line.
Claim 3
Dependent Claim
99 words
A switching network as claimed in claim 1, wherein said each transformer further includes a second secondary winding having one end connected to a reference potential and the other end connected to a corresponding incoming or outgoing line, said first secondary winding having one end connected to the reference potential and the other end connected to one of said first capacitors for generating a signal reverse in phase to that supplied to said primary winding, and said primary winding having both its ends connected to an incoming terminal or an outgoing terminal of a corresponding incoming or outgoing line.
Claim 4
Dependent Claim
15 words
A switching network as claimed in claim 2, wherein said switching elements are semiconductor devices.
Claim 5
Dependent Claim
16 words
A switching network as claimed in claim 3, wherein said semiconductor devices are silicon controlled rectifiers.
Claim 6
Dependent Claim
110 words
A switching network as claimed in claim 1, wherein said primary winding of each transformer has one end connected to the reference potential and the other end connected to one or more incoming or outgoing lines through one of a second plurality of capacitors for blocking a direct current, and said secondary winding of each transformer has one end connected to the reference potential and the other end connected to one or more incoming or outgoing lines adjacent to said one or more incoming or outgoing lines through corresponding ones of said first plurality of capacitors each generating a signal reverse in phase to that supplied to said primary winding.
Claim 7
Dependent Claim
15 words
A switching network as claimed in claim 5, wherein said switching elements are semiconductor devices.
Claim 8
Dependent Claim
16 words
A switching network as claimed in claim 6, wherein said semiconductor devices are silicon controlled rectifiers.
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) | 1980-10-10 | 1981-04-11 | 1981-10-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-10-10 | 1985-04-11 | 1985-10-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-10-10 | 1989-04-11 | 1989-10-11 | $7700.00 | Window Closed / Lapsed |