JPS5679594A - Receiver for multifrequency signal - Google Patents

Receiver for multifrequency signal

Info

Publication number
JPS5679594A
JPS5679594A JP15638779A JP15638779A JPS5679594A JP S5679594 A JPS5679594 A JP S5679594A JP 15638779 A JP15638779 A JP 15638779A JP 15638779 A JP15638779 A JP 15638779A JP S5679594 A JPS5679594 A JP S5679594A
Authority
JP
Japan
Prior art keywords
circuit
signal
threshold value
output
input
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.)
Granted
Application number
JP15638779A
Other languages
Japanese (ja)
Other versions
JPS5915238B2 (en
Inventor
Harutomo Narita
Masanori Nakamura
Shogo Usuda
Seiji Hagino
Akira Ito
Shinji Goto
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.)
Fujitsu Ltd
Hitachi Ltd
NEC Corp
Nippon Telegraph and Telephone Corp
Oki Electric Industry Co Ltd
Original Assignee
Fujitsu Ltd
Hitachi Ltd
NEC Corp
Nippon Telegraph and Telephone Corp
Oki Electric Industry Co Ltd
Nippon Electric Co Ltd
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 Fujitsu Ltd, Hitachi Ltd, NEC Corp, Nippon Telegraph and Telephone Corp, Oki Electric Industry Co Ltd, Nippon Electric Co Ltd filed Critical Fujitsu Ltd
Priority to JP54156387A priority Critical patent/JPS5915238B2/en
Publication of JPS5679594A publication Critical patent/JPS5679594A/en
Publication of JPS5915238B2 publication Critical patent/JPS5915238B2/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
    • H04Q1/46—Signalling arrangements; Manipulation of signalling currents using alternate current with voice-band signalling frequencies comprising means for distinguishing between a signalling current of predetermined frequency and a complex current containing that frequency, e.g. speech current

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Digital Transmission Methods That Use Modulated Carrier Waves (AREA)

Abstract

PURPOSE:To surely suppress a spurious signal such as an echo, by making stable the operation of a variable threshold value control circuit with a simple circuit, through the use of a variable threshold value control system and addition of the fixed threshold value to an input signal itself in a control circuit. CONSTITUTION:The signal K passing through a band block filter is input to a variable threshold value circuit 32' via a signal amplifier 31' and a capacitor C1, this input is half-wave-rectified at a differential input operational amplifier IC2 and a diode D1, and the maximum voltage is charged in a capacitor C2 and stored. The output of a fixed threshold value circuit 33' and the input signal of said circuit 32' are compared at the 1st comparison circuit 34' and output (l) and an output (m) of the circuit 32' are compared at the 2nd comparison circuit 35'. Further, the tail edge of the input signal is detected by the output signal (o) rectifying the output (n) at the rectifying circuit 36', to discriminate the input signal and the spurious signal.
JP54156387A 1979-12-04 1979-12-04 multifrequency signal receiver Expired JPS5915238B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP54156387A JPS5915238B2 (en) 1979-12-04 1979-12-04 multifrequency signal receiver

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP54156387A JPS5915238B2 (en) 1979-12-04 1979-12-04 multifrequency signal receiver

Publications (2)

Publication Number Publication Date
JPS5679594A true JPS5679594A (en) 1981-06-30
JPS5915238B2 JPS5915238B2 (en) 1984-04-07

Family

ID=15626627

Family Applications (1)

Application Number Title Priority Date Filing Date
JP54156387A Expired JPS5915238B2 (en) 1979-12-04 1979-12-04 multifrequency signal receiver

Country Status (1)

Country Link
JP (1) JPS5915238B2 (en)

Also Published As

Publication number Publication date
JPS5915238B2 (en) 1984-04-07

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