GB883825A - Improvements in or relating to private automatic telephone exchanges - Google Patents
Improvements in or relating to private automatic telephone exchangesInfo
- Publication number
- GB883825A GB883825A GB1868157A GB1868157A GB883825A GB 883825 A GB883825 A GB 883825A GB 1868157 A GB1868157 A GB 1868157A GB 1868157 A GB1868157 A GB 1868157A GB 883825 A GB883825 A GB 883825A
- Authority
- GB
- United Kingdom
- Prior art keywords
- relay
- call
- comes
- automatic
- public address
- 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
- H04M—TELEPHONIC COMMUNICATION
- H04M11/00—Telephonic communication systems specially adapted for combination with other electrical systems
- H04M11/02—Telephonic communication systems specially adapted for combination with other electrical systems with bell or annunciator systems
- H04M11/022—Paging systems
Landscapes
- Engineering & Computer Science (AREA)
- Signal Processing (AREA)
- Sub-Exchange Stations And Push- Button Telephones (AREA)
Abstract
883,825. Automatic - exchange systems. AUTOPHONE Ltd. June 4, 1958 [June 13, 1957], No. 18681/57. Class 40 (4). A private automatic-exchange comprises arrangements for connecting a calling substation to a loud-speaking general call or public address system when a call is not answered. The connection to the general call system may be automatic after a delay equivalent to form ringing cycles. In a modification, an extra digit is dialled to obtain the connection. The call may be answered from any substation by dialling a code digit. Automatic connection. (Prov. Fig.). A test relay H (winding not shown) pulls up when the called substation tests free on final selector FS and two-step relay PA comes up (first step) over contact h. The driving circuit of finder HS is completed over x contact pa4 and the switch is stepped to find the final selector FS which is now marked with battery on the bank of wiper e. Relay ST comes up when wiper e finds battery and timing relays T, M interact to measure the delay. Both relays T, M are up together at the end of the delay period. If the call is still unanswered, relay CR comes up and PA takes the second step, connecting the incoming line a, b to the public address amplifier input terminals over contacts pa1(y), pa3(y). An announcement is made from the calling station. A code is dialled from any station and a final selector FS is stepped to its last outlet. Relay AN comes up and interconnects the two substations over the a and b wipers of FS, HS. In a modification, the terminals 11, 12 give access to a public address operator who makes the necessary announcement. Connection to public address system obtained by dialling. (Comp. Fig.). An extra digit is dialled when no reply is received. Relay PA takes both steps in response to an impulse repeated by contact j1 in the control circuit of FS. As before, switch HS finds the final selector FS and ST comes up to connect the incoming line a, b to the amplifier input. The call is answered as before.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB1868157A GB883825A (en) | 1957-06-13 | 1957-06-13 | Improvements in or relating to private automatic telephone exchanges |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB1868157A GB883825A (en) | 1957-06-13 | 1957-06-13 | Improvements in or relating to private automatic telephone exchanges |
Publications (1)
Publication Number | Publication Date |
---|---|
GB883825A true GB883825A (en) | 1961-12-06 |
Family
ID=10116596
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB1868157A Expired GB883825A (en) | 1957-06-13 | 1957-06-13 | Improvements in or relating to private automatic telephone exchanges |
Country Status (1)
Country | Link |
---|---|
GB (1) | GB883825A (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3668317A (en) * | 1970-05-07 | 1972-06-06 | Bell Telephone Labor Inc | Automatic personal signaling system |
-
1957
- 1957-06-13 GB GB1868157A patent/GB883825A/en not_active Expired
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3668317A (en) * | 1970-05-07 | 1972-06-06 | Bell Telephone Labor Inc | Automatic personal signaling system |
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