GB2212029A - An ancillary device for a telephone connected to a telephone line - Google Patents
An ancillary device for a telephone connected to a telephone line Download PDFInfo
- Publication number
- GB2212029A GB2212029A GB8800631A GB8800631A GB2212029A GB 2212029 A GB2212029 A GB 2212029A GB 8800631 A GB8800631 A GB 8800631A GB 8800631 A GB8800631 A GB 8800631A GB 2212029 A GB2212029 A GB 2212029A
- Authority
- GB
- United Kingdom
- Prior art keywords
- voltage
- resistor
- load
- telephone
- ancillary device
- 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.)
- Withdrawn
Links
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04M—TELEPHONIC COMMUNICATION
- H04M1/00—Substation equipment, e.g. for use by subscribers
- H04M1/60—Substation equipment, e.g. for use by subscribers including speech amplifiers
- H04M1/6033—Substation equipment, e.g. for use by subscribers including speech amplifiers for providing handsfree use or a loudspeaker mode in telephone sets
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04M—TELEPHONIC COMMUNICATION
- H04M1/00—Substation equipment, e.g. for use by subscribers
- H04M1/66—Substation equipment, e.g. for use by subscribers with means for preventing unauthorised or fraudulent calling
- H04M1/663—Preventing unauthorised calls to a telephone set
-
- 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
- H04M19/04—Current supply arrangements for telephone systems providing ringing current or supervisory tones, e.g. dialling tone or busy tone the ringing-current being generated at the substations
-
- 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
Landscapes
- Engineering & Computer Science (AREA)
- Signal Processing (AREA)
- Computer Security & Cryptography (AREA)
- Devices For Supply Of Signal Current (AREA)
- Selective Calling Equipment (AREA)
- Interconnected Communication Systems, Intercoms, And Interphones (AREA)
- Telephone Function (AREA)
- Communication Cables (AREA)
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE3736797 | 1987-10-30 | ||
DE19873740026 DE3740026A1 (de) | 1987-10-30 | 1987-11-26 | Zusatzeinrichtung zu einem an einer telefonleitung angeschlossenen telefon |
Publications (2)
Publication Number | Publication Date |
---|---|
GB8800631D0 GB8800631D0 (en) | 1988-02-10 |
GB2212029A true GB2212029A (en) | 1989-07-12 |
Family
ID=25861284
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB8800631A Withdrawn GB2212029A (en) | 1987-10-30 | 1988-01-12 | An ancillary device for a telephone connected to a telephone line |
Country Status (5)
Country | Link |
---|---|
DE (1) | DE3740026A1 (no) |
DK (1) | DK158288A (no) |
GB (1) | GB2212029A (no) |
NO (1) | NO880103L (no) |
SE (1) | SE8801048L (no) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE4140153C2 (de) * | 1991-12-05 | 2003-04-03 | Tenovis Gmbh & Co Kg | Schaltungsanordnung für einen Fernsprechapparat mit einer Tonrufschaltung |
Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3673339A (en) * | 1970-07-22 | 1972-06-27 | Bell Telephone Labor Inc | Artificial line busy circuit |
GB1425894A (en) * | 1972-03-21 | 1976-02-18 | Socotel | Telephone line testing devices |
-
1987
- 1987-11-26 DE DE19873740026 patent/DE3740026A1/de not_active Withdrawn
-
1988
- 1988-01-12 NO NO88880103A patent/NO880103L/no unknown
- 1988-01-12 GB GB8800631A patent/GB2212029A/en not_active Withdrawn
- 1988-03-22 SE SE8801048A patent/SE8801048L/ not_active Application Discontinuation
- 1988-03-23 DK DK158288A patent/DK158288A/da not_active IP Right Cessation
Patent Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3673339A (en) * | 1970-07-22 | 1972-06-27 | Bell Telephone Labor Inc | Artificial line busy circuit |
GB1425894A (en) * | 1972-03-21 | 1976-02-18 | Socotel | Telephone line testing devices |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE4140153C2 (de) * | 1991-12-05 | 2003-04-03 | Tenovis Gmbh & Co Kg | Schaltungsanordnung für einen Fernsprechapparat mit einer Tonrufschaltung |
Also Published As
Publication number | Publication date |
---|---|
NO880103L (no) | 1989-05-02 |
DK158288A (da) | 1989-05-01 |
DK158288D0 (da) | 1988-03-23 |
GB8800631D0 (en) | 1988-02-10 |
SE8801048D0 (sv) | 1988-03-22 |
NO880103D0 (no) | 1988-01-12 |
DE3740026A1 (de) | 1989-05-11 |
SE8801048L (sv) | 1989-05-01 |
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Legal Events
Date | Code | Title | Description |
---|---|---|---|
WAP | Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1) |