GB282153A - Improvements in telephone systems - Google Patents
Improvements in telephone systemsInfo
- Publication number
- GB282153A GB282153A GB2269426A GB2269426A GB282153A GB 282153 A GB282153 A GB 282153A GB 2269426 A GB2269426 A GB 2269426A GB 2269426 A GB2269426 A GB 2269426A GB 282153 A GB282153 A GB 282153A
- Authority
- GB
- United Kingdom
- Prior art keywords
- relay
- busy
- over
- operates
- 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
- H04Q3/00—Selecting arrangements
Landscapes
- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Interface Circuits In Exchanges (AREA)
Abstract
282,153. Standard Telephones & Cables, Ltd., and Haigh, L. B. Sept. 14, 1926. Automatic and semi-automatic exchange systems.-In a system in which an operator can offer a trunk call to a busy subscriber, the connector over which the call is offered is of the type employed in the establishment of ordinary connections without any additional apparatus, the change-over relay being energized over a fourth wire to switch the connection through. Setting up connection. Relays A and B operate and prepare an impulsing circuit for the vertical magnet V and a relay C in parallel. After the " tens " impulses have finished, relay C deenergizes. and the " units " impulses operate the rotary magnet R and a slow relay E in parallel. If the subscriber is busy, relay G energizes over its winding (4, 3), E (8, 6), P, and operates its fly contacts 5, 6. When E relapses, G fully operates [battery, G (4, 3), E (8, 7), G (5, 6), G (2, 1), H (25, 26), B (8, 9), earth], opening the rotary impulsing circuit at G (7, 8), and substituting busy flash for earth on the (4, 3) winding of relay A, and connects " busy hold " to B (4, 3) at G (10, 11). When the subscriber hangs up, relays A, B, G release in turn, and a circuit [ground, A (6, 5), B (6, 5), N (2, 1), Z to battery] is closed for the release magnet Z. If the line is free, when E releases, the test relay H energizes in two stages. Ringing-current and ring-back tone are now sent. When the called party answers, relay F pulls up in two stages and switches the wanted line through to the backbridge relay D to complete the talking circuit and send back the supervisory signal. When the calling party hangs up, relays A, B, H, F, D restore in turn and the release magnet Z operates to return the switch to normal. If the called party hangs up first, an alarm lamp LP will glow, and after a predetermined time an alarm will be given. When an operator calls. the operation of the switch is as above if the line is free, and if busy, the relay G operates as before. The trunk-offering group selector grounds its fourth wiper either under control of the operator, after busy tone has been received, or as soon as the connector is seized. Relay C now energizes over contacts G (16, 17), and closes a talking circuit over C (11, 12), G (18', 19), and C (13, 14), G (20, 21), the subscriber receiving feed from the connector to which be is already connected. The operator now offers the call in the usual manner.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB2269426A GB282153A (en) | 1926-09-14 | 1926-09-14 | Improvements in telephone systems |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB2269426A GB282153A (en) | 1926-09-14 | 1926-09-14 | Improvements in telephone systems |
Publications (1)
Publication Number | Publication Date |
---|---|
GB282153A true GB282153A (en) | 1927-12-14 |
Family
ID=10183585
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB2269426A Expired GB282153A (en) | 1926-09-14 | 1926-09-14 | Improvements in telephone systems |
Country Status (1)
Country | Link |
---|---|
GB (1) | GB282153A (en) |
-
1926
- 1926-09-14 GB GB2269426A patent/GB282153A/en not_active Expired
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