GB699941A - Improvements in or relating to apparatus for supplying ringing current in automatic telephone-exchange and like systems - Google Patents
Improvements in or relating to apparatus for supplying ringing current in automatic telephone-exchange and like systemsInfo
- Publication number
- GB699941A GB699941A GB28023/51A GB2802351A GB699941A GB 699941 A GB699941 A GB 699941A GB 28023/51 A GB28023/51 A GB 28023/51A GB 2802351 A GB2802351 A GB 2802351A GB 699941 A GB699941 A GB 699941A
- Authority
- GB
- United Kingdom
- Prior art keywords
- tube
- line
- potential
- conductive
- discharge path
- 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
- H04M19/02—Current supply arrangements for telephone systems providing ringing current or supervisory tones, e.g. dialling tone or busy tone
- H04M19/026—Arrangements for interrupting the ringing current
Landscapes
- Engineering & Computer Science (AREA)
- Signal Processing (AREA)
- Devices For Supply Of Signal Current (AREA)
Abstract
699,941. Automatic exchange systems. PHILIPS ELECTRICAL INDUSTRIES, Ltd. Nov. 29, 1951 [Dec. 2, 1950], No. 28023/51. Class 40 (iv). [Also in Group XL (c)] In an automatic telephone system of the kind in which the talking connection to a called line is established by a selector comprising a discharge tube of which an output electrode is coupled with the line and means is provided to render a discharge path to that electrode conductive when the line is called, ringing current is supplied to a called line through a discharge path of an additional discharge tube which is controlled in accordance with the voltages of the output electrode and of a conductor of the line so that the discharge path of the additional tube is conductive for part at least of each period of the ringing current if the discharge path of the first tube is conductive and the line loop is not closed. In the simplest form (Fig. 1), the additional tube BB is normally extinguished but when the path OB becomes conductive (line L selected) the potential of point Q drops and the potential difference between the anode a and cathode k exceeds the starting voltage of tube BB for part of the ringing cycle of generator WG. Tube BB may extinguish during the negative half-cycles but will fire again for the positive. On the reply of the called party the potential of Q increases and tube BB is extinguished. In the embodiment of Fig. 2 the discharge path OB is coupled to the line L1, L2 by a transformer and the tube BB fires when the voltage difference between the starting electrode f and the cathode k exceeds a critical value. When the line is selected current flow through R4 raises the potential at Q and tube BB fires, but on the reply of the called party the potential of k increases and that of f decreases so that tube BB is extinguished. In a modification (Fig. 3 not shown), the tube BB has two starting electrodes, one connected to Q and the other to L1. The cathode k is connected to L2 and the connection from L2 via R6 to Q is omitted. Generation of ringing current, Fig. 4. The tube BB which is a gas-filled triode has its anode and cathode connected to L1 and L2 respectively, and its grid to point Q. When the line is selected the potential of Q rises, BB conducts and discharges C1 rapidly whereupon BB becomes non-conductive. C1 is recharged slowly through R2 and R3 and the tube BB again conducts and so on. On the reply of the called party the potential across BB is reduced so that BB remains cut off.
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
NL699941X | 1950-12-02 |
Publications (1)
Publication Number | Publication Date |
---|---|
GB699941A true GB699941A (en) | 1953-11-18 |
Family
ID=19809003
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB28023/51A Expired GB699941A (en) | 1950-12-02 | 1951-11-29 | Improvements in or relating to apparatus for supplying ringing current in automatic telephone-exchange and like systems |
Country Status (5)
Country | Link |
---|---|
BE (1) | BE507510A (en) |
DE (1) | DE885726C (en) |
FR (1) | FR1054169A (en) |
GB (1) | GB699941A (en) |
NL (1) | NL157702B (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE1074662B (en) * | 1957-10-10 | 1960-02-04 | Pye Limited, Cambridge (Grossbritannien) | Automatic telephone system with electronic switching of the ringing current to a subscriber |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
BE524389A (en) * | 1952-11-20 |
-
0
- NL NL7412172.A patent/NL157702B/en unknown
- BE BE507510D patent/BE507510A/xx unknown
-
1951
- 1951-11-29 GB GB28023/51A patent/GB699941A/en not_active Expired
- 1951-11-29 DE DEN4763A patent/DE885726C/en not_active Expired
- 1951-11-30 FR FR1054169D patent/FR1054169A/en not_active Expired
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE1074662B (en) * | 1957-10-10 | 1960-02-04 | Pye Limited, Cambridge (Grossbritannien) | Automatic telephone system with electronic switching of the ringing current to a subscriber |
US2990454A (en) * | 1957-10-10 | 1961-06-27 | Pye Ltd | Telephone systems |
Also Published As
Publication number | Publication date |
---|---|
FR1054169A (en) | 1954-02-09 |
BE507510A (en) | |
DE885726C (en) | 1953-08-06 |
NL157702B (en) |
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