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
Application number
FR7231571A
Other languages
French (fr)
Other versions
FR2152669A1 (en
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
AT&T Corp
Original Assignee
Western Electric Co Inc
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Western Electric Co Inc filed Critical Western Electric Co Inc
Publication of FR2152669A1 publication Critical patent/FR2152669A1/fr
Application granted granted Critical
Publication of FR2152669B1 publication Critical patent/FR2152669B1/fr
Expired legal-status Critical Current

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)
  • Inductance-Capacitance Distribution Constants And Capacitance-Resistance Oscillators (AREA)
  • Digital Transmission Methods That Use Modulated Carrier Waves (AREA)
  • Push-Button Switches (AREA)
  • Electronic Switches (AREA)
  • Tone Control, Compression And Expansion, Limiting Amplitude (AREA)
  • Interface Circuits In Exchanges (AREA)
  • Telephonic Communication Services (AREA)
FR7231571A 1971-09-07 1972-09-06 Expired FR2152669B1 (en)

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)

* Cited by examiner, † Cited by third party
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)

* Cited by examiner, † Cited by third party
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

Also Published As

Publication number Publication date
JPS4837005A (en) 1973-05-31
CA958083A (en) 1974-11-19
IT965227B (en) 1974-01-31
ES406799A1 (en) 1975-10-16
DE2243625C3 (en) 1975-04-17
DE2243625B2 (en) 1974-08-29
US3699477A (en) 1972-10-17
GB1411418A (en) 1975-10-22
BE788462A (en) 1973-01-02
DE2243625A1 (en) 1973-03-15
JPS5228522B2 (en) 1977-07-27
FR2152669A1 (en) 1973-04-27
NL7212067A (en) 1973-03-09

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Legal Events

Date Code Title Description
ST Notification of lapse