NO742913L - - Google Patents

Info

Publication number
NO742913L
NO742913L NO742913A NO742913A NO742913L NO 742913 L NO742913 L NO 742913L NO 742913 A NO742913 A NO 742913A NO 742913 A NO742913 A NO 742913A NO 742913 L NO742913 L NO 742913L
Authority
NO
Norway
Prior art keywords
signal
frequency
counter
voltage
periods
Prior art date
Application number
NO742913A
Other languages
English (en)
Norwegian (no)
Inventor
H Ball
W Ohl
Original Assignee
Int Standard Electric Corp
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 Int Standard Electric Corp filed Critical Int Standard Electric Corp
Publication of NO742913L publication Critical patent/NO742913L/no

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
    • H04Q1/457—Signalling arrangements; Manipulation of signalling currents using alternate current with voice-band signalling frequencies using multi-frequency signalling with conversion of multifrequency signals into digital signals

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Measuring Frequencies, Analyzing Spectra (AREA)
  • Digital Transmission Methods That Use Modulated Carrier Waves (AREA)
  • Mobile Radio Communication Systems (AREA)
NO742913A 1973-08-16 1974-08-14 NO742913L (it)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE19732341225 DE2341225B2 (de) 1973-08-16 1973-08-16 Selektiver zeichenempfaenger fuer fernmelde-, insbesondere fernsprechanlagen

Publications (1)

Publication Number Publication Date
NO742913L true NO742913L (it) 1975-03-17

Family

ID=5889793

Family Applications (1)

Application Number Title Priority Date Filing Date
NO742913A NO742913L (it) 1973-08-16 1974-08-14

Country Status (14)

Country Link
US (1) US3935395A (it)
BE (1) BE818725A (it)
BR (1) BR7406644D0 (it)
CH (1) CH586986A5 (it)
DE (1) DE2341225B2 (it)
DK (1) DK432374A (it)
ES (1) ES429267A1 (it)
FR (1) FR2241075B1 (it)
GB (1) GB1460996A (it)
HK (1) HK44177A (it)
NL (1) NL7410653A (it)
NO (1) NO742913L (it)
SE (1) SE7410344L (it)
ZA (1) ZA744858B (it)

Families Citing this family (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2540859C2 (de) * 1975-09-13 1984-01-12 Standard Elektrik Lorenz Ag, 7000 Stuttgart Schaltungsanordnung für einen selektiven Zeichenempfänger, insbesondere für Fernsprechanlagen
US4021620A (en) * 1975-12-04 1977-05-03 Rca Corporation Multifrequency signal receiver with digital tone receiver
US4061885A (en) * 1975-12-17 1977-12-06 Motorola, Inc. Digital tone decoder
US4158110A (en) * 1977-08-25 1979-06-12 Tone Commander Systems, Inc. Tone selective key telephone intercom system including digital tone detector
IT1097753B (it) * 1978-07-28 1985-08-31 Chimosa Chimica Organica Spa Compcsti piperidinici, processo per la loro preparazione e loro impiego come stabil izzanti per polimeri sintetici
FR2485843B1 (fr) * 1980-06-25 1986-11-07 Cit Alcatel Recepteur numerique de frequences
DE3115151A1 (de) * 1981-04-15 1982-11-11 Licentia Patent-Verwaltungs-Gmbh, 6000 Frankfurt Schaltungsanordnung zur auswertung von aus mehreren gleichzeitig uebertragenen wechselstroemen unterschiedlicher signalfrequenzen gebildeten wechselstromsignalen, in fernmeldeanlagen
US4675898A (en) * 1984-12-07 1987-06-23 Buscom Systems, Inc. Single tone telephone receiver
US5610978A (en) * 1994-12-30 1997-03-11 Mitel Corporation Ring discriminator

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3537001A (en) * 1968-12-05 1970-10-27 Bell Telephone Labor Inc Multifrequency tone detector
US3760269A (en) * 1972-07-31 1973-09-18 Gte Automatic Electric Lab Inc Multi-frequency tone detector
US3790720A (en) * 1972-10-27 1974-02-05 Northern Electric Co Digital decoder for multiple frequency telephone signalling

Also Published As

Publication number Publication date
DE2341225B2 (de) 1976-10-28
FR2241075B1 (it) 1978-02-17
SE7410344L (it) 1975-02-17
CH586986A5 (it) 1977-04-15
DK432374A (it) 1975-04-28
US3935395A (en) 1976-01-27
ES429267A1 (es) 1976-08-16
BE818725A (nl) 1975-02-12
GB1460996A (en) 1977-01-06
NL7410653A (nl) 1975-02-18
FR2241075A1 (it) 1975-03-14
HK44177A (en) 1977-09-09
ZA744858B (en) 1975-08-27
DE2341225A1 (de) 1975-02-20
BR7406644D0 (pt) 1975-09-09

Similar Documents

Publication Publication Date Title
US3937899A (en) Tone detector using spectrum parameter estimation
US10157603B2 (en) Noise detector and sound signal output device
US3949177A (en) Method for frequency-recognition in selective signal receivers for use in telecommunication, particularly telephone systems
KR960030072A (ko) 현악기/타악기용 피치인식방법
KR970019380A (ko) 칼라 비디오 신호의 노이즈를 검출하는 장치(apparatus for detecting noise in a color video signal)
SE501981C2 (sv) Förfarande och anordning för diskriminering mellan stationära och icke stationära signaler
US20160191390A1 (en) System and Method for Detecting VOIP Traffic
EP0576980B1 (en) A method of improving sensitivity and speech immunity of a multifrequency receiver
Wu et al. Measurement of interstation phase velocity by wavelet transformation
KR900001161A (ko) Dtmf 수신기
US4206775A (en) Coin sorting machine
KR100386485B1 (ko) 개선된음을갖는전송시스템
US3238303A (en) Wave analyzing system
RU2425394C2 (ru) Способ обнаружения искаженных импульсных сигналов
US3935395A (en) Selective signal receiver for use in telecommunication systems
US2593694A (en) Wave analyzer for determining fundamental frequency of a complex wave
EP0988758A1 (en) Tone detection with aliasing bandpass filters
US3544723A (en) Tone detector
Ohno et al. A simple model of cyclostationary power-line noise for communication systems
CA2279264C (en) Speech immunity enhancement in linear prediction based dtmf detector
US3971897A (en) Circuit arrangement for a selective signal receiver, particularly for use in telephone systems
ITTO970626A1 (it) Procedimento e dispositivo per la misurazione dei parametri dell'eco su linee telefoniche.
US3509281A (en) Voicing detection system
SE443240B (sv) Sett och anordning for bestemning av en formodad signals spektrala fordelning
KR940023082A (ko) 디지탈 전송 시스템