FR2373934A1 - Telephone system tuned filter circuit - has several tuned sections each preceded by operational amplifier receiving output of adjacent section - Google Patents

Telephone system tuned filter circuit - has several tuned sections each preceded by operational amplifier receiving output of adjacent section

Info

Publication number
FR2373934A1
FR2373934A1 FR7637276A FR7637276A FR2373934A1 FR 2373934 A1 FR2373934 A1 FR 2373934A1 FR 7637276 A FR7637276 A FR 7637276A FR 7637276 A FR7637276 A FR 7637276A FR 2373934 A1 FR2373934 A1 FR 2373934A1
Authority
FR
France
Prior art keywords
tuned
preceded
operational amplifier
sections
filter circuit
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.)
Withdrawn
Application number
FR7637276A
Other languages
French (fr)
Inventor
Claude Boulanger
Philippe Regent
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.)
Alcatel CIT SA
Original Assignee
Alcatel CIT SA
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 Alcatel CIT SA filed Critical Alcatel CIT SA
Priority to FR7637276A priority Critical patent/FR2373934A1/en
Priority to BE1008528A priority patent/BE861001A/en
Priority to IT30300/77A priority patent/IT1088733B/en
Priority to DE19772754026 priority patent/DE2754026A1/en
Priority to NL7713443A priority patent/NL7713443A/en
Priority to PL20270377A priority patent/PL202703A1/en
Priority to BR7708213A priority patent/BR7708213A/en
Priority to SE7714018A priority patent/SE7714018L/en
Priority to LU78661A priority patent/LU78661A1/xx
Publication of FR2373934A1 publication Critical patent/FR2373934A1/en
Withdrawn legal-status Critical Current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
    • H04Q1/45—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)

Abstract

The filter circuit is designed to detect frequencies in the range 700-1700 Hertz. The circuit consists of several filter sections. Each section is tuned to a particular frequency and is preceded by an operational amplifier. For a multifrequency system fi (i = 1, 2--K..) the filter sections (2-5), which are tuned to frequencies f2-fK-1, are each preceded by an operational amplifier (10-13). In addition to the input signal each operational amplifier receives signals from the neighbouring filter sections, i.e. fi+1 and fi-1. The filter sections (1 and 6) tuned to the lowest and highest frequencies (f, and fk) are also preceded by operational amplifiers (9 and 14). The amplifiers receive, in addition to the input signal, the output signal of the neighbouring section i.e. f2 and fk-1.
FR7637276A 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 Withdrawn FR2373934A1 (en)

Priority Applications (9)

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
BE1008528A BE861001A (en) 1976-12-10 1977-11-21 FILTERING DEVICE FOR DETECTION OF MULTIPLE FREQUENCIES
IT30300/77A IT1088733B (en) 1976-12-10 1977-12-02 FILTERING DEVICE FOR THE DETECTION OF MORE FREQUENCIES
DE19772754026 DE2754026A1 (en) 1976-12-10 1977-12-05 FILTER DEVICE FOR DETERMINING SEVERAL FREQUENCIES IN AN ELECTRICAL SIGNAL
NL7713443A NL7713443A (en) 1976-12-10 1977-12-05 FILTER CHAIN FOR DETECTING SOME FREQUENCIES.
PL20270377A PL202703A1 (en) 1976-12-10 1977-12-07 ELECTRICAL SIGNAL FILTERING DEVICE FOR SEVERAL FREQUENCY DETECTION
BR7708213A BR7708213A (en) 1976-12-10 1977-12-09 ELECTRIC SIGNAL FILTERING DEVICE
SE7714018A SE7714018L (en) 1976-12-10 1977-12-09 DEVICE FOR FILTERING AN ELECTRICAL SIGNAL
LU78661A LU78661A1 (en) 1976-12-10 1977-12-09

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
FR2373934A1 true FR2373934A1 (en) 1978-07-07

Family

ID=9180912

Family Applications (1)

Application Number Title Priority Date Filing Date
FR7637276A Withdrawn 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

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
BR7708213A (en) 1978-09-05
BE861001A (en) 1978-05-22
DE2754026A1 (en) 1978-06-15
IT1088733B (en) 1985-06-10
PL202703A1 (en) 1978-08-28
NL7713443A (en) 1978-06-13
SE7714018L (en) 1978-06-11
LU78661A1 (en) 1978-07-12

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Legal Events

Date Code Title Description
ST Notification of lapse