GB395035A - Improvements in or relating to telephone or like signalling systems - Google Patents
Improvements in or relating to telephone or like signalling systemsInfo
- Publication number
- GB395035A GB395035A GB1063/32A GB106332A GB395035A GB 395035 A GB395035 A GB 395035A GB 1063/32 A GB1063/32 A GB 1063/32A GB 106332 A GB106332 A GB 106332A GB 395035 A GB395035 A GB 395035A
- Authority
- GB
- United Kingdom
- Prior art keywords
- currents
- speech
- circuits
- bands
- control
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B3/00—Line transmission systems
- H04B3/02—Details
- H04B3/20—Reducing echo effects or singing; Opening or closing transmitting path; Conditioning for transmission in one direction or the other
Landscapes
- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Signal Processing (AREA)
- Cable Transmission Systems, Equalization Of Radio And Reduction Of Echo (AREA)
Abstract
395,035. Echo-suppressors and like control circuits. ELECTRICAL RESEARCH PRODUCTS, Inc., 195, Broadway, New York, U.S.A.-(Assignees of Dudley, H. W. ; 123, South Oraton Parkway, East Orange, New Jersey, U.S.A.) Jan. 13, 1932, No. 1063. Convention date, Jan. 30, 1931. [Class 40 (iv).] A control circuit, e.g. an echo-suppressor, which discriminates between speech or signal currents and noise currents comprises an element adapted to operate only in response to an unequal distribution of energy over a certain frequency range. As shown in the Figure, the windings of the differential relay 4 are connected to parallel circuits including amplifier-rectifiers 7, 10 and selective circuits 8, 11 (tuned circuits or bandpass filters) which transmit adjacent sub-bands of small width, so that noise currents produce no effect since the energy in the sub-bands is substantially the same. In an extension of this arrangement, three parallel circuits transmitting adjacent sub-bands are connected in pairs to three differential relays having their contacts arranged in parallel. The Specification describes the application of the control circuit in the terminal station of a four-wire system with radio links employing control currents of frequencies outside the speech band which flow concurrently with the speech currents, filters being provided to confine the speech and control currents to their proper channels. Specifications 142,115 and 206,715, [both in Class 40 (iv), Telephones &c.], are referred to.
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US512246A US1971679A (en) | 1931-01-30 | 1931-01-30 | Transmission control circuits |
Publications (1)
Publication Number | Publication Date |
---|---|
GB395035A true GB395035A (en) | 1933-07-13 |
Family
ID=24038288
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB1063/32A Expired GB395035A (en) | 1931-01-30 | 1932-01-13 | Improvements in or relating to telephone or like signalling systems |
Country Status (2)
Country | Link |
---|---|
US (1) | US1971679A (en) |
GB (1) | GB395035A (en) |
Families Citing this family (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
NL80093C (en) * | 1950-06-16 | |||
US4414602A (en) * | 1981-12-18 | 1983-11-08 | Minnesota Mining And Manufacturing Co. | Current director and interface circuit for a transformer relay |
-
1931
- 1931-01-30 US US512246A patent/US1971679A/en not_active Expired - Lifetime
-
1932
- 1932-01-13 GB GB1063/32A patent/GB395035A/en not_active Expired
Also Published As
Publication number | Publication date |
---|---|
US1971679A (en) | 1934-08-28 |
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