GB487488A - Improvements in signal receiving apparatus for telephone systems - Google Patents

Improvements in signal receiving apparatus for telephone systems

Info

Publication number
GB487488A
GB487488A GB2508/38A GB250838A GB487488A GB 487488 A GB487488 A GB 487488A GB 2508/38 A GB2508/38 A GB 2508/38A GB 250838 A GB250838 A GB 250838A GB 487488 A GB487488 A GB 487488A
Authority
GB
United Kingdom
Prior art keywords
tuned circuit
jan
signal currents
receiving apparatus
signal receiving
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
GB2508/38A
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.)
Koninklijke Philips NV
Original Assignee
Philips Gloeilampenfabrieken NV
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 Philips Gloeilampenfabrieken NV filed Critical Philips Gloeilampenfabrieken NV
Publication of GB487488A publication Critical patent/GB487488A/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
    • H04Q1/444—Signalling arrangements; Manipulation of signalling currents using alternate current with voice-band signalling frequencies
    • H04Q1/446—Signalling arrangements; Manipulation of signalling currents using alternate current with voice-band signalling frequencies using one signalling frequency
    • H04Q1/4465—Signalling arrangements; Manipulation of signalling currents using alternate current with voice-band signalling frequencies using one signalling frequency the same frequency being used for all signalling information, e.g. A.C. nr.9 system

Abstract

487,488. Voice - frequency signalling. NAAMLOOZE VENNOOTSCHAP PHILIPS' CLOEILAMPENFABRIEKEN. Jan. 26, 1938, No. 2508. Convention date, Jan. 29, 1937. [Class 40 (iv)] [Also in Group XL] A speech amplifier 3 responds to signal currents, e.g. ringing current and selecting impulses, of comparatively large amplitude and of a frequency within the speech band by means of a tuned circuit 5 which through a rectifier 6 and a resistance 7 and condenser 8 applies a direct voltage bias to the grid to release a normally operated relay 9 in the anode circuit. The tuned circuit 5 may be connected across the secondary of the input transformer 1, or across the primary, Fig. 2 (not shown). The coil of the tuned circuit has an iron core in order to give a broad resonance curve for the amplitude of the signal currents.
GB2508/38A 1937-01-29 1938-01-26 Improvements in signal receiving apparatus for telephone systems Expired GB487488A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE201132X 1937-01-29

Publications (1)

Publication Number Publication Date
GB487488A true GB487488A (en) 1938-06-21

Family

ID=5764685

Family Applications (1)

Application Number Title Priority Date Filing Date
GB2508/38A Expired GB487488A (en) 1937-01-29 1938-01-26 Improvements in signal receiving apparatus for telephone systems

Country Status (4)

Country Link
US (1) US2251958A (en)
CH (1) CH201132A (en)
FR (1) FR832795A (en)
GB (1) GB487488A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1063220B (en) * 1954-12-16 1959-08-13 Sueddeutsche Telefon App Kabel Tonrufempfaenger or converter for tone selection or tone control purposes for radio systems with selective call systems, in particular for radio networks with mobile radio systems

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR963277A (en) * 1947-02-21 1950-07-05
SG137753A1 (en) * 2006-05-24 2007-12-28 Inventio Ag Elevator with frictional drive

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1063220B (en) * 1954-12-16 1959-08-13 Sueddeutsche Telefon App Kabel Tonrufempfaenger or converter for tone selection or tone control purposes for radio systems with selective call systems, in particular for radio networks with mobile radio systems

Also Published As

Publication number Publication date
US2251958A (en) 1941-08-12
CH201132A (en) 1938-11-15
FR832795A (en) 1938-10-03

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