ES442422A1 - Detection of call answer signals in a communication syste - Google Patents

Detection of call answer signals in a communication syste

Info

Publication number
ES442422A1
ES442422A1 ES442422A ES442422A ES442422A1 ES 442422 A1 ES442422 A1 ES 442422A1 ES 442422 A ES442422 A ES 442422A ES 442422 A ES442422 A ES 442422A ES 442422 A1 ES442422 A1 ES 442422A1
Authority
ES
Spain
Prior art keywords
carbon atoms
atoms
radicals
general formula
alkyl
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
Application number
ES442422A
Other languages
Spanish (es)
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
Priority claimed from US05/521,734 external-priority patent/US3978293A/en
Priority claimed from US05/521,651 external-priority patent/US3978292A/en
Application filed by Western Electric Co Inc filed Critical Western Electric Co Inc
Publication of ES442422A1 publication Critical patent/ES442422A1/en
Expired legal-status Critical Current

Links

Classifications

    • 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
    • H04M19/026—Arrangements for interrupting the ringing current

Abstract

Procedure for preparing oxatiinno [1,4] [2,3-c] pyrrole derivatives, which correspond to the general formula **(See formula)** in which A represents a phenyl, pyridyl-2, pyridazinyl-3, quinolyl-2 or naphthyridinyl radical, these radicals are optionally substituted by one or two atoms or radicals, identical or different, selected from halogen atoms and alkyl radicals containing from 1 to 4 carbon atoms, alkyloxy where the alkyl part contains from 1 to 4 carbon atoms and nitro, and the symbol R represents an alkyl radical containing from 1 to 4 carbon atoms, cycloalkyl containing from 3 to 6 carbon atoms, alkenyl containing from 2 to 4 carbon atoms or alkynyl containing from 2 to 4 carbon atoms, as well as their addition salts with acids, characterized in that a piperazine of general formula is reacted: **(See formula)** in which R is defined as above, with a mixed carbonate of general formula: **(See formula)** in which A is defined as above and Ar represents a phenyl radical optionally substituted by an alkyl radical containing from 1 to 4 carbon or nitro atoms, and then, optionally, the product obtained is transformed into an addition salt with an acid . (Machine-translation by Google Translate, not legally binding)
ES442422A 1974-11-07 1975-11-07 Detection of call answer signals in a communication syste Expired ES442422A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US05/521,734 US3978293A (en) 1974-11-07 1974-11-07 Ringing control circuitry with shared ringing loop current detector
US05/521,651 US3978292A (en) 1974-11-07 1974-11-07 Ringing control circuitry with shared ringing loop current detector

Publications (1)

Publication Number Publication Date
ES442422A1 true ES442422A1 (en) 1977-08-16

Family

ID=27060535

Family Applications (1)

Application Number Title Priority Date Filing Date
ES442422A Expired ES442422A1 (en) 1974-11-07 1975-11-07 Detection of call answer signals in a communication syste

Country Status (9)

Country Link
JP (1) JPS5169906A (en)
BR (1) BR7507193A (en)
DE (1) DE2549469C2 (en)
ES (1) ES442422A1 (en)
FR (1) FR2290805A1 (en)
GB (1) GB1515720A (en)
IT (1) IT1048758B (en)
NL (1) NL7513016A (en)
SE (1) SE7512060L (en)

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2755639C2 (en) * 1977-12-14 1985-06-05 Telefonbau Und Normalzeit Gmbh, 6000 Frankfurt Circuit arrangement for the logical processing of subscriber criteria in telecommunications, in particular telephone switching systems
FR2451682A1 (en) * 1979-03-12 1980-10-10 Jeumont Schneider CALL DEVICE FOR AUTOMATIC SUBSCRIBER TELEPHONE INSTALLATION WITH ADDITIONAL STATIONS
JPS56119565A (en) * 1981-02-12 1981-09-19 Hitachi Ltd Signal processing device in subscriber's circuit

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3720793A (en) * 1971-09-01 1973-03-13 Bell Telephone Labor Inc Supervisory circuit arrangement for telephone subscriber lines
FR2171594A5 (en) * 1972-02-08 1973-09-21 Constr Telephoniques
FR2172537A5 (en) * 1972-02-17 1973-09-28 Constr Telephoniques

Also Published As

Publication number Publication date
NL7513016A (en) 1976-05-11
DE2549469A1 (en) 1976-05-13
FR2290805B1 (en) 1981-02-06
JPS5169906A (en) 1976-06-17
SE7512060L (en) 1976-05-10
IT1048758B (en) 1980-12-20
FR2290805A1 (en) 1976-06-04
BR7507193A (en) 1976-08-10
JPS571171B2 (en) 1982-01-09
DE2549469C2 (en) 1984-05-17
GB1515720A (en) 1978-06-28

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