BE788813A - FREQUENCY SELECTIVE SIGNAL RECEIVER AND PROTECTED AGAINST VOICE SIGNALS FOR TELECOMMUNICATION INSTALLATIONS, ESPECIALLY TELEPHONY INSTALLATIONS - Google Patents
FREQUENCY SELECTIVE SIGNAL RECEIVER AND PROTECTED AGAINST VOICE SIGNALS FOR TELECOMMUNICATION INSTALLATIONS, ESPECIALLY TELEPHONY INSTALLATIONSInfo
- Publication number
- BE788813A BE788813A BE788813DA BE788813A BE 788813 A BE788813 A BE 788813A BE 788813D A BE788813D A BE 788813DA BE 788813 A BE788813 A BE 788813A
- Authority
- BE
- Belgium
- Prior art keywords
- installations
- signal receiver
- protected against
- voice signals
- frequency selective
- Prior art date
Links
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04Q—SELECTING
- H04Q1/00—Details of selecting apparatus or arrangements
- H04Q1/18—Electrical details
- H04Q1/30—Signalling arrangements; Manipulation of signalling currents
- H04Q1/44—Signalling arrangements; Manipulation of signalling currents using alternate current
- H04Q1/444—Signalling arrangements; Manipulation of signalling currents using alternate current with voice-band signalling frequencies
- H04Q1/45—Signalling arrangements; Manipulation of signalling currents using alternate current with voice-band signalling frequencies using multi-frequency signalling
- H04Q1/457—Signalling arrangements; Manipulation of signalling currents using alternate current with voice-band signalling frequencies using multi-frequency signalling with conversion of multifrequency signals into digital signals
Landscapes
- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Monitoring And Testing Of Exchanges (AREA)
- Interface Circuits In Exchanges (AREA)
- Mobile Radio Communication Systems (AREA)
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE19712145886 DE2145886C2 (en) | 1971-09-14 | 1971-09-14 | Voice-protected, frequency-selective signal receiver for telecommunications, in particular telephone systems |
DE19712156123 DE2156123C2 (en) | 1971-11-11 | 1971-11-11 | Frequency-selective character receiver for telecommunications, in particular telephone systems |
Publications (1)
Publication Number | Publication Date |
---|---|
BE788813A true BE788813A (en) | 1973-03-14 |
Family
ID=25761724
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
BE788813D BE788813A (en) | 1971-09-14 | FREQUENCY SELECTIVE SIGNAL RECEIVER AND PROTECTED AGAINST VOICE SIGNALS FOR TELECOMMUNICATION INSTALLATIONS, ESPECIALLY TELEPHONY INSTALLATIONS |
Country Status (9)
Country | Link |
---|---|
AT (1) | AT328516B (en) |
BE (1) | BE788813A (en) |
CH (1) | CH545569A (en) |
FR (1) | FR2153943A5 (en) |
GB (1) | GB1402119A (en) |
IT (1) | IT967367B (en) |
LU (1) | LU66057A1 (en) |
NL (1) | NL7212486A (en) |
SE (1) | SE397461B (en) |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4216463A (en) * | 1978-08-10 | 1980-08-05 | Motorola, Inc. | Programmable digital tone detector |
-
0
- BE BE788813D patent/BE788813A/en unknown
-
1972
- 1972-08-17 AT AT713372A patent/AT328516B/en not_active IP Right Cessation
- 1972-08-21 CH CH545569D patent/CH545569A/xx not_active IP Right Cessation
- 1972-09-11 FR FR7232114A patent/FR2153943A5/fr not_active Expired
- 1972-09-12 LU LU66057D patent/LU66057A1/xx unknown
- 1972-09-12 IT IT2907772A patent/IT967367B/en active
- 1972-09-13 GB GB4245972A patent/GB1402119A/en not_active Expired
- 1972-09-13 SE SE1182472A patent/SE397461B/en unknown
- 1972-09-14 NL NL7212486A patent/NL7212486A/xx not_active Application Discontinuation
Also Published As
Publication number | Publication date |
---|---|
SE397461B (en) | 1977-10-31 |
LU66057A1 (en) | 1973-01-17 |
AT328516B (en) | 1976-03-25 |
ATA713372A (en) | 1975-06-15 |
NL7212486A (en) | 1973-03-16 |
CH545569A (en) | 1974-01-31 |
FR2153943A5 (en) | 1973-05-04 |
IT967367B (en) | 1974-02-28 |
GB1402119A (en) | 1975-08-06 |
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