GB512108A - Improvements in or relating to electric communication systems - Google Patents

Improvements in or relating to electric communication systems

Info

Publication number
GB512108A
GB512108A GB35389/38A GB3538938A GB512108A GB 512108 A GB512108 A GB 512108A GB 35389/38 A GB35389/38 A GB 35389/38A GB 3538938 A GB3538938 A GB 3538938A GB 512108 A GB512108 A GB 512108A
Authority
GB
United Kingdom
Prior art keywords
dec
calling signal
relating
network
communication systems
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
GB35389/38A
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.)
Fides Gesellschaft fuer die Verwaltung und Verwertung von Gewerblichen Schutzrechten mbH
Original Assignee
Fides Gesellschaft fuer die Verwaltung und Verwertung von Gewerblichen Schutzrechten mbH
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 Fides Gesellschaft fuer die Verwaltung und Verwertung von Gewerblichen Schutzrechten mbH filed Critical Fides Gesellschaft fuer die Verwaltung und Verwertung von Gewerblichen Schutzrechten mbH
Publication of GB512108A publication Critical patent/GB512108A/en
Expired legal-status Critical Current

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
    • H04Q1/442—Signalling arrangements; Manipulation of signalling currents using alternate current with out-of-voice band signalling frequencies
    • H04Q1/4423—Signalling arrangements; Manipulation of signalling currents using alternate current with out-of-voice band signalling frequencies using one signalling frequency

Abstract

512,108. Exchange systems. FIDES GES. FUR DIE VERWALTUNG UND VERWERTUNG VON GEWERBLICHEN SCHUTZRECHTEN. Dec. 5, 1938, No. 35389. Convention date, Dec. 4, 1937. [Class 40 (iv)] [Also in Group XL] In a system in which a calling signal receiving circuit is bridged across a telephone line L, the input includes a network Z comprising a pair of rectifiers 1, 2 which is normally of high impedance and which assumes a lower impedance when the calling signal is received under the control of direct current fed back from the output, which includes an amplifier V, filter BP passing the calling frequency, and rectifier G. A steady state is eventually reached in which the output current is sufficient to operate relay R. A delay network D may be included in the feed back circuit.
GB35389/38A 1937-12-04 1938-12-05 Improvements in or relating to electric communication systems Expired GB512108A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP512108X 1937-12-04

Publications (1)

Publication Number Publication Date
GB512108A true GB512108A (en) 1939-08-29

Family

ID=12880543

Family Applications (1)

Application Number Title Priority Date Filing Date
GB35389/38A Expired GB512108A (en) 1937-12-04 1938-12-05 Improvements in or relating to electric communication systems

Country Status (1)

Country Link
GB (1) GB512108A (en)

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