GB1355129A - Individual telephone line equipment - Google Patents
Individual telephone line equipmentInfo
- Publication number
- GB1355129A GB1355129A GB5842971A GB5842971A GB1355129A GB 1355129 A GB1355129 A GB 1355129A GB 5842971 A GB5842971 A GB 5842971A GB 5842971 A GB5842971 A GB 5842971A GB 1355129 A GB1355129 A GB 1355129A
- Authority
- GB
- United Kingdom
- Prior art keywords
- line
- pulse
- point
- output
- earth
- 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
- H04M3/00—Automatic or semi-automatic exchanges
- H04M3/22—Arrangements for supervision, monitoring or testing
- H04M3/2272—Subscriber line supervision circuits, e.g. call detection circuits
Landscapes
- Engineering & Computer Science (AREA)
- Signal Processing (AREA)
- Monitoring And Testing Of Exchanges (AREA)
- Mobile Radio Communication Systems (AREA)
- Interface Circuits In Exchanges (AREA)
Abstract
1355129 Automatic exchange systems INTERNATIONAL STANDARD ELECTRIC CORP 16 Dec 1971 [23 Dec 1970] 58429/71 Heading H4K A subscriber's line circuit is arranged to give an output dependent on the line condition, e.g. whether the subscriber's line is free, calling, busy or in false call condition, when an interrogation pulse is applied to the circuit. The line L1, L2, has two resistors R1, R2 connected in series with it and the potentials occurring on either side of these resistors are used by means of circuits CT1 and CT2 to change the amplitude of an interrogation pulse received by transistor T1. The changed signal is then applied to threshold circuits DL1-DL3 from whose outputs the condition of the line can be determined. For the purposes of the following description it will be assumed that potential source - U = - 48V and potential source - u = - 6 volts, that the value of resistor R 1 = value resistor R2 = value of the resistance of the looped line L1, L2; that when an interrogation pulse is received by transistor T1 the potential applied to line E1 is charged from - 48v to - 19v and the potential applied to line E2 is charged from -48 to - 30v; finally that the potential on the emitter of transistor T4, v = + 15v. Line free.-This is characterized in that contacts A1, and A2 are closed and the line is not looped through the subscribers set Pt. The points L and M in loop detector circuit CT1 are at - 48v and earth respectively. The point N in feed test circuit CT2 is at earth. Application of the interrogation pulse therefore causes a 29v pulse level to appear at M and an 18v pulse level to appear at N, these pulse levels being transferred via respective diodes D1, D6 to transistors T3 and T4, T5 respectively. These pulses are sufficient to cause all three transistors to turn on and a 111 output is obtained (see Fig. 2). Line calling.-The line is now looped with contacts A1, A2 closed. Because of the values of R1, R2 and the loop resistance point L is now at - 32v and point M at - 16v. When the interrogation pulse is now applied only a -3v pulse level appears at M and transistor T3 does not turn on. As the point N is circuit CT2 is at earth as before transistors T4, T5 are turned on by the interrogation pulse. A 011 output is obtained indicating that the line is looped and fed by source -U via contact A2. Line connected.-When the line is connected through the exchange switching circuit RC it derives its potential source therethrough and contacts A1, A2 are open. If the supply via the network RC is such that L1 is at - 48v and L2 is at earth, point L is at earth and points M and N at - 48v. Reception of the interrogation pulse fails to cause points M and N to go positive and a 000 output is obtained. Likewise, if the line polarity is such that L1 is at earth and L2 is at - 48v, diode D5 and resistor R5 connected to a - U( - 48v) source ensure that L, M and N are all at - 48v and a 000 output is again obtained. at False call condition,-If the subscriber has off-hooked and is not participating in a call, after a time interval means, not disclosed, causes switches A1, A2 to open and switches P1, P2 to close. The potentials at the points L, M and N are then - 28v, - 14v, and - 6v respectively and the interrogation pulse causes point M to reach a pulse level of - 5v and point N to reach a pulse level of + 12v. As transistor T4 requires at least a 15v pulse to turn it on a 001 output condition is obtained. When the subscriber on-hooks, the line is no longer looped but is still being fed by P1, P2. Points L, M, N are therefore at -48v, - 6v and - 6v respectively, and the presence of the interrogation pulse causes a 23v pulse level at M and a 12v pulse level at N. A 101 output condition is therefore obtained which indicates to the exchange equipment that the false call condition has ceased, and as a result P1, P2 will be opened and A1, A2 closed.
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
FR7046461A FR2119188A5 (en) | 1970-12-23 | 1970-12-23 |
Publications (1)
Publication Number | Publication Date |
---|---|
GB1355129A true GB1355129A (en) | 1974-06-05 |
Family
ID=9066266
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB5842971A Expired GB1355129A (en) | 1970-12-23 | 1971-12-16 | Individual telephone line equipment |
Country Status (14)
Country | Link |
---|---|
AT (1) | AT315249B (en) |
AU (1) | AU464484B2 (en) |
BE (1) | BE777084A (en) |
BR (1) | BR7108538D0 (en) |
CA (1) | CA938040A (en) |
CH (1) | CH554624A (en) |
ES (1) | ES398234A1 (en) |
FR (1) | FR2119188A5 (en) |
GB (1) | GB1355129A (en) |
IT (1) | IT944014B (en) |
NL (1) | NL7117638A (en) |
NO (1) | NO136386C (en) |
SE (1) | SE369263B (en) |
SU (1) | SU584819A3 (en) |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
ZA74205B (en) * | 1973-02-12 | 1974-11-27 | Int Standard Electric Corp | Line condition signalling system |
-
1970
- 1970-12-23 FR FR7046461A patent/FR2119188A5/fr not_active Expired
-
1971
- 1971-12-02 AU AU36455/71A patent/AU464484B2/en not_active Expired
- 1971-12-16 NO NO464471A patent/NO136386C/en unknown
- 1971-12-16 IT IT3246471A patent/IT944014B/en active
- 1971-12-16 GB GB5842971A patent/GB1355129A/en not_active Expired
- 1971-12-17 AT AT1084371A patent/AT315249B/en not_active IP Right Cessation
- 1971-12-20 SU SU7101727209A patent/SU584819A3/en active
- 1971-12-21 SE SE1636871A patent/SE369263B/xx unknown
- 1971-12-22 CH CH1871171A patent/CH554624A/en not_active IP Right Cessation
- 1971-12-22 CA CA130878A patent/CA938040A/en not_active Expired
- 1971-12-22 NL NL7117638A patent/NL7117638A/xx not_active Application Discontinuation
- 1971-12-22 ES ES398234A patent/ES398234A1/en not_active Expired
- 1971-12-22 BE BE777084A patent/BE777084A/en unknown
- 1971-12-23 BR BR853871A patent/BR7108538D0/en unknown
Also Published As
Publication number | Publication date |
---|---|
SE369263B (en) | 1974-08-12 |
AT315249B (en) | 1974-05-10 |
NO136386C (en) | 1977-08-31 |
BE777084A (en) | 1972-06-22 |
DE2162964A1 (en) | 1972-07-13 |
CH554624A (en) | 1974-09-30 |
AU464484B2 (en) | 1975-08-28 |
SU584819A3 (en) | 1977-12-15 |
NO136386B (en) | 1977-05-16 |
NL7117638A (en) | 1972-06-27 |
CA938040A (en) | 1973-12-04 |
IT944014B (en) | 1973-04-20 |
BR7108538D0 (en) | 1973-05-31 |
AU3645571A (en) | 1973-06-07 |
DE2162964B2 (en) | 1976-01-02 |
ES398234A1 (en) | 1975-03-16 |
FR2119188A5 (en) | 1972-08-04 |
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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 |