GB907374A - Improvements in or relating to telephone circuit arrangements - Google Patents

Improvements in or relating to telephone circuit arrangements

Info

Publication number
GB907374A
GB907374A GB2264461A GB2264461A GB907374A GB 907374 A GB907374 A GB 907374A GB 2264461 A GB2264461 A GB 2264461A GB 2264461 A GB2264461 A GB 2264461A GB 907374 A GB907374 A GB 907374A
Authority
GB
United Kingdom
Prior art keywords
voltage
ringer
voltages
relating
ringing
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
GB2264461A
Other languages
English (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.)
Tenovis GmbH and Co KG
Original Assignee
Telefonbau und Normalzeit GmbH
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 Telefonbau und Normalzeit GmbH filed Critical Telefonbau und Normalzeit GmbH
Publication of GB907374A publication Critical patent/GB907374A/en
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
    • H04M1/738—Interface circuits for coupling substations to external telephone lines
    • H04M1/74—Interface circuits for coupling substations to external telephone lines with means for reducing interference; with means for reducing effects due to line faults
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04M—TELEPHONIC COMMUNICATION
    • H04M1/00—Substation equipment, e.g. for use by subscribers
    • H04M1/68—Circuit arrangements for preventing eavesdropping

Landscapes

  • Engineering & Computer Science (AREA)
  • Signal Processing (AREA)
  • Devices For Supply Of Signal Current (AREA)
GB2264461A 1960-11-05 1961-06-22 Improvements in or relating to telephone circuit arrangements Expired GB907374A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DET19238A DE1195816B (de) 1960-11-05 1960-11-05 Schaltungsanordnung fuer einen mikrofoniearmen Teilnehmerapparat

Publications (1)

Publication Number Publication Date
GB907374A true GB907374A (en) 1962-10-03

Family

ID=7549244

Family Applications (1)

Application Number Title Priority Date Filing Date
GB2264461A Expired GB907374A (en) 1960-11-05 1961-06-22 Improvements in or relating to telephone circuit arrangements

Country Status (3)

Country Link
DE (1) DE1195816B (enExample)
GB (1) GB907374A (enExample)
NL (1) NL260795A (enExample)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3997737A (en) * 1974-11-27 1976-12-14 San/Bar Corporation Security line card circuit

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1278526B (de) * 1963-08-31 1968-09-26 Standard Elektrik Lorenz Ag Schaltungsanordnung zur Verhinderung des Abhoerens von Gespraechen ueber einen anrufbereiten Fernsprechapparat

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1110233B (de) * 1959-02-10 1961-07-06 Siemens Ag Schaltungsanordnung zur Verhinderung des Abhoerens von Gespraechen

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3997737A (en) * 1974-11-27 1976-12-14 San/Bar Corporation Security line card circuit

Also Published As

Publication number Publication date
NL260795A (enExample)
DE1195816B (de) 1965-07-01

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