GB201564A - Improvements in or relating to the selective transmission of electric waves - Google Patents
Improvements in or relating to the selective transmission of electric wavesInfo
- Publication number
- GB201564A GB201564A GB19171/23A GB1917123A GB201564A GB 201564 A GB201564 A GB 201564A GB 19171/23 A GB19171/23 A GB 19171/23A GB 1917123 A GB1917123 A GB 1917123A GB 201564 A GB201564 A GB 201564A
- Authority
- GB
- United Kingdom
- Prior art keywords
- line
- receiving
- transformer
- transmitting
- filters
- 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
- H04B3/36—Repeater circuits
- H04B3/38—Repeater circuits for signals in two different frequency ranges transmitted in opposite directions over the same transmission path
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04J—MULTIPLEX COMMUNICATION
- H04J1/00—Frequency-division multiplex systems
- H04J1/02—Details
- H04J1/08—Arrangements for combining channels
- H04J1/085—Terminal station; Combined modulator and demodulator circuits
Landscapes
- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Signal Processing (AREA)
- Cable Transmission Systems, Equalization Of Radio And Reduction Of Echo (AREA)
- Interconnected Communication Systems, Intercoms, And Interphones (AREA)
Abstract
201,564. Western Electric Co., Ltd., (Assignees of Vennes, H. J.). July 26, 1922, [Convention date]. Wired wireless systems; multiplex signalling; combined transmitting and receiving arrangements.-Receiving and transmitting circuits are associated with a transmission line or medium by inductively coupling the receiving-circuit to the line, and by connecting the transmitting-circuit directly in the line at an electrical mid-point. As shown, the main line ML is connected through a high-pass filter HPF to the primary coil 5 of a transformer, which is divided at its middle point for the connection of the transmission circuit TC. The receiving-circuit RC includes the other coil of the transformer. Low-frequency telephone currents in the line L are transmitted through a balanced transformer 6 to a valve M which modulates the oscillatory current generated by the valve O and transmits the modulated current through a band filter SBF and, if desired, a second filter TGF to the transmitting line TC. The high-frequency currents received from the line ML pass through band filters GF and RBF to a detector D and thence through a voice-frequency filter VF to the low-frequency line L. Several channels employing different frequencies may be associated with the transmitting and receiving lines TC, RC, selection being effected by band filters such as SBF, RBF, while filters TGF and GF may be arranged to pass the whole set of transmitting and receiving frequencies respectively. The first elements of the receiving filters have low impedance at transmitter frequencies, so that the receiving-coil of the transformer is practically short-circuited as regards currents coming in from the line TC. The effect of this is to reduce the impedance of the line coil of the transformer 5 for the transmitter frequencies. The first elements of the transmitter band filters are similarly arranged to have low impedance for receiver frequencies, and thus form practically a short-circuit connection between the two portions of the line coil 5 for carrier currents coming in on the line ML. An earthed electrostatic shield 11 is arranged between the two windings of the transformer 5. The line ML may transmit lowfrequency currents through a low-pass filter LPF to an ordinary telephone line TL. The filters are of the kind described in Specification 142,115.
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US577493A US1501691A (en) | 1922-07-26 | 1922-07-26 | Selective transmission of electric waves |
Publications (1)
Publication Number | Publication Date |
---|---|
GB201564A true GB201564A (en) | 1924-09-11 |
Family
ID=24308964
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB19171/23A Expired GB201564A (en) | 1922-07-26 | 1923-07-26 | Improvements in or relating to the selective transmission of electric waves |
Country Status (3)
Country | Link |
---|---|
US (1) | US1501691A (en) |
FR (1) | FR569019A (en) |
GB (1) | GB201564A (en) |
Families Citing this family (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6850618B1 (en) * | 2000-05-15 | 2005-02-01 | Centillium Communications, Inc. | Central office interface techniques for digital subscriber lines |
US6826278B2 (en) | 2000-05-15 | 2004-11-30 | Centillium Communications, Inc. | Central office interface techniques for digital subscriber lines |
-
1922
- 1922-07-26 US US577493A patent/US1501691A/en not_active Expired - Lifetime
-
1923
- 1923-07-25 FR FR569019D patent/FR569019A/en not_active Expired
- 1923-07-26 GB GB19171/23A patent/GB201564A/en not_active Expired
Also Published As
Publication number | Publication date |
---|---|
US1501691A (en) | 1924-07-15 |
FR569019A (en) | 1924-04-05 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US2264396A (en) | Power line carrier frequency telephone system | |
GB405026A (en) | Carrier current transmission system | |
GB201564A (en) | Improvements in or relating to the selective transmission of electric waves | |
US1453387A (en) | System for communicating with moving vehicles | |
US2134850A (en) | Signal transmission | |
US1812624A (en) | Telephone and telegraph signaling system | |
US1502814A (en) | High-erequency multiplex signaling system | |
US2131388A (en) | Apparatus for communication systems | |
US1672940A (en) | Carrier transmission over power circuits | |
US1455827A (en) | Selective circuit for multiplex transmission | |
US1448408A (en) | Duplex carrier wave system | |
US1766919A (en) | Duplex telegraph system | |
US1601969A (en) | Call signaling system | |
US1529801A (en) | Multiplex submarine cable | |
US1602019A (en) | Carrier wave signaling system | |
US1502813A (en) | High-frequency multiplex signaling system | |
US1733553A (en) | Power-line carrier-current system | |
US1687432A (en) | Composite signaling system | |
US1314828A (en) | Harold s | |
US1702068A (en) | Coupling circuits | |
US1716908A (en) | Duplex system of telephony | |
US1722081A (en) | Two-way signaling system | |
US800157A (en) | Telegraphy. | |
US1366650A (en) | Signaling system | |
US1601967A (en) | Carrier-wave transmission |