BE861001A - FILTERING DEVICE FOR DETECTION OF MULTIPLE FREQUENCIES - Google Patents

FILTERING DEVICE FOR DETECTION OF MULTIPLE FREQUENCIES

Info

Publication number
BE861001A
BE861001A BE1008528A BE1008528A BE861001A BE 861001 A BE861001 A BE 861001A BE 1008528 A BE1008528 A BE 1008528A BE 1008528 A BE1008528 A BE 1008528A BE 861001 A BE861001 A BE 861001A
Authority
BE
Belgium
Prior art keywords
detection
filtering device
multiple frequencies
frequencies
filtering
Prior art date
Application number
BE1008528A
Other languages
French (fr)
Original Assignee
Cit Alcatel
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 Cit Alcatel filed Critical Cit Alcatel
Publication of BE861001A publication Critical patent/BE861001A/en

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
    • H04Q1/45—Signalling arrangements; Manipulation of signalling currents using alternate current with voice-band signalling frequencies using multi-frequency signalling
    • H04Q1/453—Signalling arrangements; Manipulation of signalling currents using alternate current with voice-band signalling frequencies using multi-frequency signalling in which m-out-of-n signalling frequencies are transmitted

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Networks Using Active Elements (AREA)
BE1008528A 1976-12-10 1977-11-21 FILTERING DEVICE FOR DETECTION OF MULTIPLE FREQUENCIES BE861001A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
FR7637276A FR2373934A1 (en) 1976-12-10 1976-12-10 Telephone system tuned filter circuit - has several tuned sections each preceded by operational amplifier receiving output of adjacent section

Publications (1)

Publication Number Publication Date
BE861001A true BE861001A (en) 1978-05-22

Family

ID=9180912

Family Applications (1)

Application Number Title Priority Date Filing Date
BE1008528A BE861001A (en) 1976-12-10 1977-11-21 FILTERING DEVICE FOR DETECTION OF MULTIPLE FREQUENCIES

Country Status (9)

Country Link
BE (1) BE861001A (en)
BR (1) BR7708213A (en)
DE (1) DE2754026A1 (en)
FR (1) FR2373934A1 (en)
IT (1) IT1088733B (en)
LU (1) LU78661A1 (en)
NL (1) NL7713443A (en)
PL (1) PL202703A1 (en)
SE (1) SE7714018L (en)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3831047A1 (en) * 1988-09-12 1990-03-22 Nixdorf Computer Ag CIRCUIT ARRANGEMENT FOR FREQUENCY SELECTIVE DETECTION OF SOUND SIGNALS

Also Published As

Publication number Publication date
DE2754026A1 (en) 1978-06-15
LU78661A1 (en) 1978-07-12
NL7713443A (en) 1978-06-13
PL202703A1 (en) 1978-08-28
FR2373934A1 (en) 1978-07-07
BR7708213A (en) 1978-09-05
SE7714018L (en) 1978-06-11
IT1088733B (en) 1985-06-10

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