EP0617560A1
Expired / Lapsed
EP
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Video adapter
Assignee: AT&T Inc
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Filing: 1994-03-16
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Granted: —
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Expires: 2014-03-16
Abstract
Abstract Disclosed is an adapter (FIG. 3) which permits transmission of red, green and blue video signals over separate unshielded twisted wire pairs (not shown, but connected to terminals 7,8; 6,3; 2,1). Crosstalk is minimized by wideband video chokes (T₁-T₃) coupled to each signal input/output.
Inventors
- 👤 William Hugo Georger
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-06 08:47
CPC Classifications
H; H04; H04N; H04N7/00; H04N7/10; H04N7/108
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
92 words
A device (30) for applying separate color components of a video baseband signal onto separate twisted pairs of wires (40) comprising: a plurality of first ports (31-33), each adapted for coupling to a separate one of the color components; and a second port (34) including means (1-8) for electrically connecting the device to twisted pairs of wires; CHARACTERIZED BY a plurality of transformers (T₁ - T₃) each electrically coupling to a corresponding one of the first ports to a separate twisted pair of wires, each transformer exhibiting a high degree of balance.
Claim 2
Dependent Claim
24 words
The device according to claim 1 wherein each transformer has a common mode rejection greater than 40 dB for frequencies up to 50 MHz.
Claim 3
Dependent Claim
14 words
The device according to claim 1 wherein each transformer has a bifilar winding arrangement.
Claim 4
Dependent Claim
14 words
The device according to claim 1 wherein radiated emissions are less than 32 dBµV/m.
Claim 5
Dependent Claim
26 words
The device according to claim 1 wherein the frequency response of each transformer is within ± 0.5 dB in the DC to 30 MHz frequency range.
Claim 6
Dependent Claim
20 words
The device according to claim 1 wherein each transformer includes a magnetic core with a permeability of greater than 10,000.
Claim 7
Dependent Claim
56 words
The device according to claim 1 wherein the means for electrically connecting the transformers to a separate twisted pair comprises a modular jack (34) with separate pairs of pins (7 and 8, 3 and 6, 1 and 2) coupled to each transformer and a further pair of pins (4 and 5) not coupled to any transformer.
Claim 8
Dependent Claim
52 words
The device according to claim 7 wherein wire pairs to be coupled to the second port have a certain average phase delay and the pins coupled to the transformers are adapted for coupling to twisted pairs having a deviation in phase delay from the average which is no more than 3 percent.
References Cited (Backward Citations)
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