JPS5628587A - Multifrequency signal detection system - Google Patents

Multifrequency signal detection system

Info

Publication number
JPS5628587A
JPS5628587A JP10465779A JP10465779A JPS5628587A JP S5628587 A JPS5628587 A JP S5628587A JP 10465779 A JP10465779 A JP 10465779A JP 10465779 A JP10465779 A JP 10465779A JP S5628587 A JPS5628587 A JP S5628587A
Authority
JP
Japan
Prior art keywords
output
signal
circuits
noise
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.)
Granted
Application number
JP10465779A
Other languages
Japanese (ja)
Other versions
JPS6230556B2 (en
Inventor
Hirotsugu Ishikawa
Shinji Yorihiro
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.)
NEC Corp
Original Assignee
NEC Corp
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 NEC Corp, Nippon Electric Co Ltd filed Critical NEC Corp
Priority to JP10465779A priority Critical patent/JPS5628587A/en
Publication of JPS5628587A publication Critical patent/JPS5628587A/en
Publication of JPS6230556B2 publication Critical patent/JPS6230556B2/ja
Granted 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)
  • Digital Transmission Methods That Use Modulated Carrier Waves (AREA)

Abstract

PURPOSE:To prevent the output from being generated even if noise is received, by differentiating the output of a rectifying circuit to distinguish the signal, which has a small level change in respect to time, and noise, which has a large level change in respect to time, from each other. CONSTITUTION:The signal of each frequency included in the multifrequency signal is supplied to comparators 4-1 and 4-2 through filters 2-1 and 2-2 and rectifying circuits 3-1 and 3-2, and the output is output if it is a fixed level or more. Meanwhile, outputs of respective rectifying circuits are added by adder 8 and are differentiated by differentiating circuit 5, and the output is generated from comparator 7 to inhibit AND circuits 6-1 and 6-2 if the differentiated signal is a fixed level or more. That is, if the signal is input, AND circuits 6-1 and 6-2 are not inhibited, and the output of NAND circuit 9 is 0, and the output of delay circuit 10 is 0; and if noise is input, AND circuits are inhibited, and the output of NAND circuit 9 becomes 1, and 1 is output from delay circuit 10. Thus, the signal and noise can be distinguished from each other.
JP10465779A 1979-08-17 1979-08-17 Multifrequency signal detection system Granted JPS5628587A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP10465779A JPS5628587A (en) 1979-08-17 1979-08-17 Multifrequency signal detection system

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP10465779A JPS5628587A (en) 1979-08-17 1979-08-17 Multifrequency signal detection system

Publications (2)

Publication Number Publication Date
JPS5628587A true JPS5628587A (en) 1981-03-20
JPS6230556B2 JPS6230556B2 (en) 1987-07-02

Family

ID=14386527

Family Applications (1)

Application Number Title Priority Date Filing Date
JP10465779A Granted JPS5628587A (en) 1979-08-17 1979-08-17 Multifrequency signal detection system

Country Status (1)

Country Link
JP (1) JPS5628587A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH03202166A (en) * 1989-12-27 1991-09-03 Alloy Koki Kk Atomizing apparatus and painting apparatus

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH03202166A (en) * 1989-12-27 1991-09-03 Alloy Koki Kk Atomizing apparatus and painting apparatus

Also Published As

Publication number Publication date
JPS6230556B2 (en) 1987-07-02

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