GB759687A - Improvements in and relating to automatic exchanges - Google Patents
Improvements in and relating to automatic exchangesInfo
- Publication number
- GB759687A GB759687A GB2870350A GB2870350A GB759687A GB 759687 A GB759687 A GB 759687A GB 2870350 A GB2870350 A GB 2870350A GB 2870350 A GB2870350 A GB 2870350A GB 759687 A GB759687 A GB 759687A
- Authority
- GB
- United Kingdom
- Prior art keywords
- pulses
- pulse
- channel
- frequency
- subscriber
- 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
- H04Q—SELECTING
- H04Q11/00—Selecting arrangements for multiplex systems
- H04Q11/04—Selecting arrangements for multiplex systems for time-division multiplexing
Landscapes
- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Interface Circuits In Exchanges (AREA)
- Devices For Supply Of Signal Current (AREA)
Abstract
759,687. Automatic exchange systems. GENERAL ELECTRIC CO., Ltd. Nov. 23, 1951 [Nov. 23, 1950], No. 28703/50. Class 40 (4). An automatic exchange system comprises a series of low-grade channels equal in number to the number of subscribers and a smaller number of high-grade channels for speech transmission, a calling subscriber's line circuit seizing a highgrade channel and also in response to the dialled digits a low-grade channel in which is transmitted a signal indicative of the high-grade channel seized. This signal is fed to the called subscriber's line circuit for which it serves as a seizing signal and effects the connection thereof with the highgrade channel to complete the connection. As shown, Fig. 1, calling subscriber's line circuit 12 seizes a calling unit 15 permanently associated with one end of a highgrade channel which comprises a go and a return path of the multiplex speech junctions 17, 18. Pulses for determining the time position of the channel in the multiplex system are obtained by combining a " d " and a " u " pulse from the high-frequency pulse generator 14. The calling unit 15 also seizes a register 23 which is then set by the dialled digits and selects a set of MCDU pulses from the generator 26 which are then combined to produce a single 100Á sec. pulse which recurs at intervals of one second, the time position of this pulse in the cycle denoting the wanted subscriber's number. This pulse position constitutes a lowgrade channel in the signalling junction 25 and to this channel a pair of d<1> and u<1> pulses from the low-frequency pulse generator 21 designating the calling unit (and hence the highgrade channel) are fed from the calling unit via the register. Each subscriber's line circuit 13 is provided by the MCDU pulse generator 26 with a pulse coincident with that determining the corresponding low-grade channel in junction 25 and this pulse is used to gate in the d<1> and u<1> pulses received from the signalling junction. The called subscriber's line circuit is seized thereby, whereupon it seizes a free called unit 16 and feeds the d<1> and u<1> pulses thereto. These pulses are used to set a " translator " which then selects a pair of d and u pulses from the high-frequency generator 14 which are combined to produce a gating pulse for connecting the called unit to the selected highgrade junction. With the exception that some of the gating circuits are modified to cater for the slightly different signalling arrangements between the register 23 and the called subscriber's line circuits 13, the circuits are substantially identical with those described in Specification 759,682. Busy signalling, release and metering arrangements are also identical in the two cases. Pulse supplies. The high-frequency pulse generator 14 is identical with that described in Specification 759,682. The low-frequency generator 21 may comprise an oscillator followed by a differentiating circuit feeding a frequency divider whose output feeds the first of a succession of " flip-flops " each of which on restoring triggers the next. The d<1> and u<1> pulses are obtained from the outputs of these " flip-flops," Fig. 14 (not shown). The output from the above-mentioned frequency divider is also fed to a further frequency divider (¸10) which then feeds a further series of " flip-flops " to generate the U pulses. Further stages of frequency dividers and " flip-flops " generate the D, C and M pulses, Fig. 16 (not shown). Specifications 759,683 and 759,684 also are referred to.
Priority Applications (5)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
NL88816D NL88816C (en) | 1950-11-23 | ||
NL7001668.A NL165384B (en) | 1950-11-23 | METHOD OF SEPARATING A CRYSTALLIZABLE SUBSTANCE. | |
GB2870350A GB759687A (en) | 1950-11-23 | 1950-11-23 | Improvements in and relating to automatic exchanges |
DEG7464A DE939516C (en) | 1950-11-23 | 1951-11-20 | Circuit arrangement for telecommunications systems with dialing and memory operation |
FR1048946D FR1048946A (en) | 1950-11-23 | 1951-11-23 | Automatic telephone exchange |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB2870350A GB759687A (en) | 1950-11-23 | 1950-11-23 | Improvements in and relating to automatic exchanges |
Publications (1)
Publication Number | Publication Date |
---|---|
GB759687A true GB759687A (en) | 1956-10-24 |
Family
ID=10279754
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB2870350A Expired GB759687A (en) | 1950-11-23 | 1950-11-23 | Improvements in and relating to automatic exchanges |
Country Status (4)
Country | Link |
---|---|
DE (1) | DE939516C (en) |
FR (1) | FR1048946A (en) |
GB (1) | GB759687A (en) |
NL (2) | NL88816C (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN105523878A (en) * | 2016-03-08 | 2016-04-27 | 曲靖众一精细化工股份有限公司 | Method for purifying industrial fluorine with drum |
-
0
- NL NL7001668.A patent/NL165384B/en unknown
- NL NL88816D patent/NL88816C/xx active
-
1950
- 1950-11-23 GB GB2870350A patent/GB759687A/en not_active Expired
-
1951
- 1951-11-20 DE DEG7464A patent/DE939516C/en not_active Expired
- 1951-11-23 FR FR1048946D patent/FR1048946A/en not_active Expired
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN105523878A (en) * | 2016-03-08 | 2016-04-27 | 曲靖众一精细化工股份有限公司 | Method for purifying industrial fluorine with drum |
Also Published As
Publication number | Publication date |
---|---|
FR1048946A (en) | 1953-12-24 |
NL88816C (en) | |
NL165384B (en) | |
DE939516C (en) | 1956-02-23 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US2490833A (en) | All electronic line finder and selector system | |
GB650764A (en) | Telecommunication exchange | |
US2506613A (en) | Multidigit all-electronic switching system | |
US2666809A (en) | Electrical switching system | |
GB587939A (en) | Improvements in or relating to multi-channel electrical pulse communication systems | |
ES382772A1 (en) | Telecommunication switching systems | |
US2492136A (en) | Electronic telephone exchange | |
GB759687A (en) | Improvements in and relating to automatic exchanges | |
GB645867A (en) | Telecommunication exchange | |
US3428754A (en) | Conference system wherein transmitting and receiving terminals are separately connected to a talking bus | |
GB748072A (en) | Electrical communication system | |
GB1130557A (en) | Improvements in or relating to telecommunications exchange systems | |
GB722172A (en) | Improvements in or relating to automatic telephone exchange systems | |
GB759688A (en) | Improvements in and relating to telecommunication systems embodying automatic exchanges | |
GB759689A (en) | Improvements in and relating to automatic exchanges | |
US2786891A (en) | Pulse switching systems | |
US2683771A (en) | Communication switching system | |
US2652453A (en) | Multichannel radio communication system | |
GB781561A (en) | Improvements in or relating to electronic telephone exchange systems | |
GB759692A (en) | Improvements in or relating to automatic telephone systems | |
US3301960A (en) | Automatic telephone exchange systems | |
GB759693A (en) | Improvements in or relating to automatic telephone systems | |
US3354268A (en) | Synchronizing circuit for concentrator signaling system | |
GB716171A (en) | Improvements in electrical communication switching systems | |
GB398812A (en) | Improvements in or relating to telephone systems or the like |