GB1259302A - - Google Patents
Info
- Publication number
- GB1259302A GB1259302A GB1259302DA GB1259302A GB 1259302 A GB1259302 A GB 1259302A GB 1259302D A GB1259302D A GB 1259302DA GB 1259302 A GB1259302 A GB 1259302A
- Authority
- GB
- United Kingdom
- Prior art keywords
- exchange
- ringing
- subscriber
- transistor
- signal
- 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
- H04M19/00—Current supply arrangements for telephone systems
- H04M19/08—Current supply arrangements for telephone systems with current supply sources at the substations
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04Q—SELECTING
- H04Q11/00—Selecting arrangements for multiplex systems
- H04Q11/02—Selecting arrangements for multiplex systems for frequency-division multiplexing
Landscapes
- Engineering & Computer Science (AREA)
- Signal Processing (AREA)
- Computer Networks & Wireless Communication (AREA)
- Devices For Supply Of Signal Current (AREA)
- Interface Circuits In Exchanges (AREA)
Abstract
1,259,302. Automatic exchange equipment. INTERNATIONAL STANDARD ELECTRIC CORP. 23 Jan., 1969 [26 Jan., 1968], No. 3814/69. Heading H4K. A single line pair is used to connect two independent subscribers to an exchange by providing a single carrier channel for the additional subscriber with additional equipment provided at the exchange, Fig. 2 (not shown), and the subscriber, Fig. 3 (not shown). The carrier frequency is used for signalling purposes and provision is made to prevent interference between signalling signals. The additional equipment includes modulators, demodulators, amplifiers and filters for two-way transmission with hybrids to combine the send and receive voice channels together with the transistor switching and oscillator circuits associated with signalling and ringing. In operation, a ringing signal is produced by the exchange as bursts of carrier signal as transistor (71) is intermittently energized. This signal operates a transistor (131) at the substation to control a ringing generator which supplies normal ringing current. When the subscriber goes off-hook, the line is looped, the transistor switch in the ringing circuit is disabled and a carrier signal transmitted to the exchange. Dialling interrupts this signal and a relay (57) in the exchange follows to produce dialling impulses. A low-pass filter is provided at the terminations of the line for the existing subscriber. A local battery is used to power the substation equipment and is charged from the exchange battery during idle periods. The system may be used to provide an additional exchange line for a PBX.
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US70078468A | 1968-01-26 | 1968-01-26 |
Publications (1)
Publication Number | Publication Date |
---|---|
GB1259302A true GB1259302A (en) | 1972-01-05 |
Family
ID=24814855
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB1259302D Expired GB1259302A (en) | 1968-01-26 | 1969-01-23 |
Country Status (6)
Country | Link |
---|---|
JP (1) | JPS4938041B1 (en) |
BE (1) | BE727343A (en) |
CH (1) | CH505523A (en) |
ES (1) | ES362901A1 (en) |
FR (1) | FR2000800A1 (en) |
GB (1) | GB1259302A (en) |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
IT1093561B (en) * | 1978-04-04 | 1985-07-19 | Mauri & C Snc | ARTICULATED VEHICLES FOR PUBLIC TRANSPORT |
-
1969
- 1969-01-23 GB GB1259302D patent/GB1259302A/en not_active Expired
- 1969-01-24 JP JP484369A patent/JPS4938041B1/ja active Pending
- 1969-01-24 FR FR6901334A patent/FR2000800A1/fr not_active Withdrawn
- 1969-01-24 CH CH105969A patent/CH505523A/en not_active IP Right Cessation
- 1969-01-24 BE BE727343D patent/BE727343A/xx unknown
- 1969-01-24 ES ES362901A patent/ES362901A1/en not_active Expired
Also Published As
Publication number | Publication date |
---|---|
DE1903141B2 (en) | 1972-10-19 |
DE1903141A1 (en) | 1969-08-28 |
BE727343A (en) | 1969-07-24 |
ES362901A1 (en) | 1970-09-01 |
FR2000800A1 (en) | 1969-09-12 |
CH505523A (en) | 1971-03-31 |
JPS4938041B1 (en) | 1974-10-15 |
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Legal Events
Date | Code | Title | Description |
---|---|---|---|
PS | Patent sealed | ||
435 | Patent endorsed 'licences of right' on the date specified (sect. 35/1949) | ||
PCNP | Patent ceased through non-payment of renewal fee |