FR2152669B1 - - Google Patents
Info
- Publication number
- FR2152669B1 FR2152669B1 FR7231571A FR7231571A FR2152669B1 FR 2152669 B1 FR2152669 B1 FR 2152669B1 FR 7231571 A FR7231571 A FR 7231571A FR 7231571 A FR7231571 A FR 7231571A FR 2152669 B1 FR2152669 B1 FR 2152669B1
- Authority
- FR
- France
- 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
- H04M1/00—Substation equipment, e.g. for use by subscribers
- H04M1/26—Devices for calling a subscriber
- H04M1/30—Devices which can set up and transmit only one digit at a time
- H04M1/50—Devices which can set up and transmit only one digit at a time by generating or selecting currents of predetermined frequencies or combinations of frequencies
Landscapes
- Engineering & Computer Science (AREA)
- Signal Processing (AREA)
- Digital Transmission Methods That Use Modulated Carrier Waves (AREA)
- Inductance-Capacitance Distribution Constants And Capacitance-Resistance Oscillators (AREA)
- Push-Button Switches (AREA)
- Tone Control, Compression And Expansion, Limiting Amplitude (AREA)
- Interface Circuits In Exchanges (AREA)
- Electronic Switches (AREA)
- Telephonic Communication Services (AREA)
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US17812671A | 1971-09-07 | 1971-09-07 |
Publications (2)
Publication Number | Publication Date |
---|---|
FR2152669A1 FR2152669A1 (en) | 1973-04-27 |
FR2152669B1 true FR2152669B1 (en) | 1976-03-12 |
Family
ID=22651310
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
FR7231571A Expired FR2152669B1 (en) | 1971-09-07 | 1972-09-06 |
Country Status (10)
Country | Link |
---|---|
US (1) | US3699477A (en) |
JP (1) | JPS5228522B2 (en) |
BE (1) | BE788462A (en) |
CA (1) | CA958083A (en) |
DE (1) | DE2243625C3 (en) |
ES (1) | ES406799A1 (en) |
FR (1) | FR2152669B1 (en) |
GB (1) | GB1411418A (en) |
IT (1) | IT965227B (en) |
NL (1) | NL7212067A (en) |
Families Citing this family (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
NL7212510A (en) * | 1972-09-15 | 1974-03-19 | ||
CA988175A (en) * | 1974-06-14 | 1976-04-27 | Michael C.J. Cowpland | Tone generator |
US4110568A (en) * | 1976-10-08 | 1978-08-29 | Gte Atea, S.A. | Dual tone multifrequency generator |
JPS5461804A (en) * | 1977-10-26 | 1979-05-18 | Mitsubishi Electric Corp | Information transmitter |
US6326853B1 (en) * | 1999-08-26 | 2001-12-04 | Cypress Semiconductor Corp | Circuitry, architecture and method(s) for phase matching and/or reducing load capacitance, current and/or power consumption in an oscillator |
US8605889B2 (en) | 2011-11-18 | 2013-12-10 | Edward D. REGAN | Method and device for encoding characters and routing calls using expanded dual-tone multi-frequency (DTMF) encoding scheme |
Family Cites Families (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3349350A (en) * | 1964-12-04 | 1967-10-24 | Otto E Rittenbach | Frequency step filter |
US3424870A (en) * | 1965-09-14 | 1969-01-28 | Bell Telephone Labor Inc | Multifrequency signal generator for tone-dialed telephones |
-
0
- BE BE788462D patent/BE788462A/en unknown
-
1971
- 1971-09-07 US US178126A patent/US3699477A/en not_active Expired - Lifetime
-
1972
- 1972-03-23 CA CA137,929A patent/CA958083A/en not_active Expired
- 1972-09-05 NL NL7212067A patent/NL7212067A/xx not_active Application Discontinuation
- 1972-09-06 GB GB4124872A patent/GB1411418A/en not_active Expired
- 1972-09-06 DE DE2243625A patent/DE2243625C3/en not_active Expired
- 1972-09-06 IT IT52568/72A patent/IT965227B/en active
- 1972-09-06 FR FR7231571A patent/FR2152669B1/fr not_active Expired
- 1972-09-07 JP JP47089138A patent/JPS5228522B2/ja not_active Expired
- 1972-09-07 ES ES406799A patent/ES406799A1/en not_active Expired
Also Published As
Publication number | Publication date |
---|---|
GB1411418A (en) | 1975-10-22 |
US3699477A (en) | 1972-10-17 |
DE2243625B2 (en) | 1974-08-29 |
JPS5228522B2 (en) | 1977-07-27 |
IT965227B (en) | 1974-01-31 |
JPS4837005A (en) | 1973-05-31 |
DE2243625C3 (en) | 1975-04-17 |
BE788462A (en) | 1973-01-02 |
DE2243625A1 (en) | 1973-03-15 |
CA958083A (en) | 1974-11-19 |
FR2152669A1 (en) | 1973-04-27 |
ES406799A1 (en) | 1975-10-16 |
NL7212067A (en) | 1973-03-09 |
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Legal Events
Date | Code | Title | Description |
---|---|---|---|
ST | Notification of lapse |