NO783303L - RECEIVER CONNECTION FOR TELEPHONE FEE PULSE - Google Patents
RECEIVER CONNECTION FOR TELEPHONE FEE PULSEInfo
- Publication number
- NO783303L NO783303L NO783303A NO783303A NO783303L NO 783303 L NO783303 L NO 783303L NO 783303 A NO783303 A NO 783303A NO 783303 A NO783303 A NO 783303A NO 783303 L NO783303 L NO 783303L
- Authority
- NO
- Norway
- Prior art keywords
- receiver
- frequency
- circuit
- receiver circuit
- connection
- Prior art date
Links
- 230000008878 coupling Effects 0.000 claims description 13
- 238000010168 coupling process Methods 0.000 claims description 13
- 238000005859 coupling reaction Methods 0.000 claims description 13
- 239000004020 conductor Substances 0.000 claims description 11
- 238000004804 winding Methods 0.000 claims description 11
- 230000005693 optoelectronics Effects 0.000 claims description 3
- 239000003990 capacitor Substances 0.000 description 4
- 230000000903 blocking effect Effects 0.000 description 2
- 230000003213 activating effect Effects 0.000 description 1
- 230000006978 adaptation Effects 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 238000013016 damping Methods 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04M—TELEPHONIC COMMUNICATION
- H04M15/00—Arrangements for metering, time-control or time indication ; Metering, charging or billing arrangements for voice wireline or wireless communications, e.g. VoIP
- H04M15/28—Arrangements for metering, time-control or time indication ; Metering, charging or billing arrangements for voice wireline or wireless communications, e.g. VoIP with meter at substation or with calculation of charges at terminal
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04M—TELEPHONIC COMMUNICATION
- H04M17/00—Prepayment of wireline communication systems, wireless communication systems or telephone systems
- H04M17/02—Coin-freed or check-freed systems, e.g. mobile- or card-operated phones, public telephones or booths
- H04M17/023—Circuit arrangements
Landscapes
- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Signal Processing (AREA)
- Computer Security & Cryptography (AREA)
- Meter Arrangements (AREA)
- Prepayment Telephone Systems (AREA)
Description
Oppfinnelsen angår en mottakerkopling for telefongebyrpulser, omfattende en til begge ledere i taleledningen ti.1-koplet høyfrekvens-mottakerkrets som er innrettet for høyfrekvens^telling og som oppviser en høyfrekvensveksel. The invention relates to a receiver connection for telephone charge pulses, comprising one to both conductors in the voice line ti.1-coupled high-frequency receiver circuit which is arranged for high-frequency^counting and which exhibits a high-frequency switch.
Sådanne mottakerkoplinger er kjent i telefon-selv-valgf jernt jenesten og tjener til å adski.lle gebyrpulsene, som overføres over sentralledningen eller taleledningen fra sentra- Such receiver connections are known in the telephone self-selecting service and serve to separate the charge pulses, which are transmitted over the central line or voice line from the central
len til abonnenten hhv. til et mynttelefonapparat, fra taleinnretningen, og å tilføre pulsene til et manøverorgan som driver en hos abonnenten innstallert gebyrteller eller, i et offentlig mynttelefonapparat, kassermagneten og eventuelt en gebyrindikator. For at gebyrpulsene skal være minst mulig hørbare, har man i stor utstrekning innført den såkalte høyfrekvenstelling. Frekvensene for gebyrpulsene ligger da over telefonibåndet, og er f.eks. fief to the subscriber or to a coin-operated telephone device, from the voice device, and to supply the pulses to a maneuvering device which operates a fee counter installed at the subscriber or, in a public coin-operated telephone device, the till magnet and possibly a fee indicator. In order for the fee pulses to be as little audible as possible, so-called high-frequency counting has been introduced to a large extent. The frequencies for the fee pulses are then above the telephony band, and are e.g.
12 kHz i Sveits og 16 kHz i Vest-Tyskland. 12 kHz in Switzerland and 16 kHz in West Germany.
Ved siden av disse systemer med høyfrekvenstelling eksisterer imidlertid fremdeles også i enkelte områder systemet med lavfrekvenstelling, som arbeider med 50-Hz-gebyrpulser som overføres fra sentralen over taleledningen og over jord til abonnenten. Alongside these systems with high-frequency counting, however, the system with low-frequency counting still exists in some areas, which works with 50-Hz charge pulses that are transmitted from the exchange over the voice line and over the ground to the subscriber.
Den samtidige eksistens av høyfrekvens- og 50-Hz-tellingen medfører den ulempe at det for installasjon hos abonnenten hhv. i et nyoppført mynttelefonapparat må stå til disposisjon to forskjellige mottakerkoplinger av hvilke den kopling som er tilpasset til det aktuelle, benyttede gebyrpulssystem, må innbygges.. The simultaneous existence of high-frequency and 50-Hz counting entails the disadvantage that for installation at the subscriber's or in a newly erected coin-operated telephone set, two different receiver connections must be available, of which the connection that is adapted to the relevant fee pulse system used must be built in.
Formålet med oppfinnelsen er å eliminere denne ulempe og å tilveiebringe en universell koplingsanordning som er egnet både for høyfrekvens- og for lavfrekvensstilling og som kan instal-leres, uten endringer i begge systemer. The purpose of the invention is to eliminate this disadvantage and to provide a universal coupling device which is suitable for both high-frequency and low-frequency positions and which can be installed without changes in both systems.
Med utgangspunkt i en mottaker-kopling av den inn-ledningsvis angitte type er oppfinnelsen for oppnåelse av oven-nevnte formål kjennetegnet ved at det er anordnet en ytterligere mottakerkrets for lavfrekvente gebyrpulser som "ankommer over taleledningen og jord, og at denne mottakerkrets oppviser en filterkopling som forbinder taleledningens to ledere symmetrisk med jord, og at utgangsledningene fra høyfrekvens-mottakerkretsen og lavfrekvens-mottakerkretsen er koplet til inngangene til en ELLER-kopling over hvis utgang et manøverorgan for en gebyrteller og/eller en kassérmagnet kan aktiveres. Based on a receiver connection of the type indicated in the introduction, the invention for achieving the above-mentioned purpose is characterized by the fact that an additional receiver circuit is arranged for low-frequency charge pulses that "arrive over the voice line and ground, and that this receiver circuit exhibits a filter connection which connects the two conductors of the voice line symmetrically to ground, and that the output lines from the high-frequency receiver circuit and the low-frequency receiver circuit are connected to the inputs of an OR connection over whose output a maneuvering device for a fee counter and/or a cash register magnet can be activated.
Denne mottaker-kopling har den fordel at den kan innbygges valgfritt i systemer med høyfrekvens- eller med 50-Hz-telling uten at det er nødvendig med noen som helst modifiseringer er tilpasninger. This receiver coupling has the advantage that it can optionally be built into systems with high-frequency or 50-Hz counting without any modifications or adaptations being necessary.
Anordningen er fortrinnsvis utformet slik at det foran ELLER-koplingen i begge utgangsledninger fra mottakerkretsene er innkoplet forsterkere. Mens høyfrekvensmottakerkretsen på kjent måte har en transformator som bevirker galvanisk fråkopling av The device is preferably designed so that amplifiers are connected in front of the OR connection in both output lines from the receiver circuits. While the high-frequency receiver circuit in a known manner has a transformer which causes galvanic disconnection of
gebyrpulsbearbeidelsen, kan den galvaniske fråkopling i 50-Hz-mottakerkretsen ifølge den foreliggende oppfinnelse med fordel charge pulse processing, the galvanic disconnection in the 50-Hz receiver circuit according to the present invention can advantageously
gjennomføres ved hjelp av en opto-elektronisk omformer, en såkalt fotokopier, som ligger i likestrøms-utgangskretsen for en likeretterbro hvis vekslespenningsklemmer på den ene side er koplet til filterkoplingens symmetripunkt og på den annen side er koplet til jord. is carried out by means of an opto-electronic converter, a so-called photocopier, which is located in the direct current output circuit of a rectifier bridge whose alternating voltage terminals are connected on one side to the symmetry point of the filter connection and on the other side are connected to ground.
For videre å hindre at 50-Hz-gebyrpulsene blir undertrykket dersom en av taleledningene i bedragerisk hensikt kortsluttes med jord, kan med fordel begge ledere i taleledningen være koplet induktivt over en symmetri-transformator som oppviser to'like, i den ene og den andre leder liggende primærviklinger og en sekundærvikling som over en likeretter er forbundet med lavfrekvens-mottakerkoplingens utgangsledning. På denne måte frembringer en fra sentralen ankommende 50-Hz-begyrpuls, også når en taleledning ligger til jord, som følge av den da i de to tale-léctére opptredende usymmetri en puls i mottakerkretsen, slik at gebyrtelleren eller kassérmagneten aktiveres. In order to further prevent the 50-Hz charge pulses from being suppressed if one of the voice lines is short-circuited to ground with fraudulent intent, both conductors in the voice line can be advantageously connected inductively via a symmetry transformer that exhibits two equals, in one and the other leads horizontal primary windings and a secondary winding which is connected via a rectifier to the output line of the low-frequency receiver coupling. In this way, a 50-Hz fee pulse arriving from the exchange, also when a voice line is grounded, as a result of the asymmetry then occurring in the two speech-lectures, produces a pulse in the receiver circuit, so that the fee counter or cash register magnet is activated.
Oppfinnelsen skal i det følgende beskrives nærmere under henvisning til tegningen som viser et koplingsskjerna av et utførelseseksempel på en mottakerkopling ifølge oppfinnelsen. In the following, the invention will be described in more detail with reference to the drawing which shows a connection core of an embodiment of a receiver connection according to the invention.
Til de to ledere a og b i en tale- hhv. sentral*-ledning, hvor den mot sentralen vendende ende er betegnet med Al, Bl og den med taleinnretningen forbundne abonnentende er betegnet med A2, B2, er det tilkoplet både en 50-Hz-mottakerkrets med en filterkopling 1 og en høyfrekvens-mottakerkrets med en abonnent- hhv. høyfrekvensveksel 2. Mellom denne høyfrekvens-veksel 2 og taleinnretningen er det på kjent måte anordnet enda et høyfrekvens-sperrefilter 3. Høyfre-kvens-mottakerkretsen er innrettet for høyfrekvenstelling av f.eks. 12 kHz- hhv. 16 kHz-gebyrpulser. To the two leaders a and b in a speech - respectively exchange* line, where the end facing the exchange is denoted by Al, Bl and the subscriber end connected to the voice device is denoted by A2, B2, there is connected both a 50-Hz receiver circuit with a filter connection 1 and a high-frequency receiver circuit with a subscriber - respectively high-frequency switch 2. Between this high-frequency switch 2 and the speech device, a further high-frequency blocking filter 3 is arranged in a known manner. The high-frequency receiver circuit is arranged for high-frequency counting of e.g. 12 kHz - respectively 16 kHz charge pulses.
Filterkoplingen 1 består av en mellom de to taleledere a og b beliggende dempningsbane 10 som oppviser en serle-kopling av en kondensator 11, to motstander 12 og 14 samt en kondensator 15, og er dimensjonert slik at i hovedsaken bare 50-Hz-signalene, men imidlertid ingen frekvenser fra telefonibåndet og heller ingen høyfrekvens-gebyrpulser, slippes gjennom. Det mellom de to motstander 12 og 14 beliggende symmetripunkt 13 av filterkoplingen 1 er tilkoplet til den ene vekselspenningsklemme av en likeretterbro 17 hvis andre vekselspenningsklemme er koplet til jord E. I likeretterbroens 17 likestrøms-utgangskrets ligger en opto-elektronisk omformer 5, en såkalt fotokopier, som består av en lysdiode 18 og en fra denne galvanisk adskilt fototransistor 19. På denne måte blir gebyrpuls-bearbeidelsen galvanisk adskilt fra taleledningen. Fototransistorens 19 emitter er koplet til nullpotensial mens dens 1kollektor på den ene side over en motstand er forbundet med et positivt hjelpepotensial og på den annen side over en motstand 20, som over en kondensator er forbundet med nullpotensial, er tilkoplet til en forsterker 6. Denne forsterker 6 består i det viste eksempel av en Schmitt-trigger 21 med en inverterkopling og en etterfølgende inverterkopling 22. For-sterkerens 6 utgangsledning 23 er tilkoplet til den ene inngang til en ELLER-kopling 24 hvis utgang er forbundet med et manøveror-gan 25 for påvirkning eller aktivering av en gebyrteller eller, The filter coupling 1 consists of a damping path 10 located between the two speech conductors a and b, which exhibits a Serle coupling of a capacitor 11, two resistors 12 and 14 and a capacitor 15, and is dimensioned so that essentially only the 50 Hz signals, however, no frequencies from the telephony band and no high-frequency charge pulses are allowed through. The symmetry point 13 of the filter connection 1 located between the two resistors 12 and 14 is connected to one AC voltage terminal of a rectifier bridge 17 whose other AC voltage terminal is connected to ground E. In the DC output circuit of the rectifier bridge 17 is an opto-electronic converter 5, a so-called photocopier , which consists of an LED 18 and a phototransistor 19 galvanically separated from this. In this way, the fee pulse processing is galvanically separated from the voice line. The emitter of the phototransistor 19 is connected to zero potential while its collector 1 is connected on one side via a resistor to a positive auxiliary potential and on the other side via a resistor 20, which via a capacitor is connected to zero potential, is connected to an amplifier 6. This amplifier 6 in the example shown consists of a Schmitt trigger 21 with an inverter connection and a subsequent inverter connection 22. The output line 23 of the amplifier 6 is connected to one input of an OR connection 24 whose output is connected to a control device 25 for influencing or activating a fee counter or,
i tilfelle av et offentlig mynttelefonapparat, en kassérmagnet og eventuelt en gebyrindikator. in the case of a public coin-operated telephone set, a cash register magnet and, where applicable, a fee indicator.
Høyfrekvensvekselen 2 og høyfrekvens-sperrefilteret The high-frequency converter 2 and the high-frequency blocking filter
3 er av kjent konstruksjon. En. transformator 30 i høyfrek.vens^-vekselen 2 sørger for en galvanisk fråkopling av det på basisen i en transistor 31 tilstedeværende utgangssignal. Den over en kondensator med kollektoren forbundne emitter i transistoren 31, som virker som likeretter > er over en motstand forbundet med et positivt hjelpepotensial, mens transistorens kollektor på den ene side over en motstand er forbundet med nullpotensial og på 3 is of known construction. One. transformer 30 in the high-frequency converter 2 ensures a galvanic disconnection of the output signal present at the base of a transistor 31. The emitter of the transistor 31, which acts as a rectifier, connected via a capacitor to the collector, is via a resistor connected to a positive auxiliary potential, while the collector of the transistor is connected to zero potential via a resistor on one side and on
den annen side er forbundet med en forsterker 32 som i det viste eksempel består av en Schmitt-trigger 32 med inverterkopling. Forterkerens 32 utgangsledning 33 er tilkoplet til den andre inngang til ELLER-koplingen 24. the other side is connected to an amplifier 32 which in the example shown consists of a Schmitt trigger 32 with inverter coupling. The amplifier's 32 output line 33 is connected to the second input of the OR connection 24.
Videre er de to taleledere a og b koplet induktivt over en symmetritransformator 4 som oppviser to like primærviklinger 40 hhv. 41 i a- hhv. b-lederen, samt en sekundærvikling 42 Furthermore, the two speech conductors a and b are inductively coupled via a symmetry transformer 4 which exhibits two identical primary windings 40 respectively. 41 in a- respectively the b conductor, as well as a secondary winding 42
som er koplet til vekselspenningsklemmene i. en likeretterbro 43. Likestrømsutgangen fra denne likeretterbro 4 3 styrer en transistor 34 hvis emitter er koplet til riullpotensia kollektor er forbundet med motstanden 20 til hvilken også fototransistorens 19 kollektor er tilkoplet. which is connected to the alternating voltage terminals i. a rectifier bridge 43. The direct current output from this rectifier bridge 4 3 controls a transistor 34 whose emitter is connected to the riull potential collector is connected to the resistor 20 to which the collector of the phototransistor 19 is also connected.
Når den beskrevne mottakerkopling innbygges i en When the described receiver connection is built into a
med 50-Hz-gebyrpulser arbeidende telefonledning, blir de fra sentralen over taleledningen og jord E overførte gebyrpulser over filterkoplingen 1 tilført til likeretterbroen 17 og, likerettet, til fotodioden 18. Ved hjelp av tenningen av fotodioden 18 aktiveres fototransistoren 19, og det derved tilveiebrakte utgangssignal påvirker manøverorganet 25 over forsterkeren 6 og ELLER-koplingen 24. Høyfrekvens-mottakerkretsen blir ikke påvirket av 50-Hz-gebyrpulsene. Når en telefonabonnent i bedragerisk hensikt forbinder en av de to taleledere a eller b med jord E, for på denne måte å kortslutte 50-Hz-gebyrpulsene og derved hindre en reaksjon av gebyrtelleren eller kassérmagneten, sørger symmetritransformato-ren 4 for at denne manipulasjon ikke fører til målet. Normalt oppheves de i sekundærviklingen 4 2 induserte spenninger som forår~sakes av de i de to likt dimensjonerte primærviklinger 40 og 41 sirkulerende strømmer, da disse strømmer til stadighet er like i begge primærviklinger, men er motsatt rettet. Denne symmetri, blir imidlertid forstyrret når en av talelederne a eller b kortsluttes with 50-Hz charge pulses working telephone line, the charge pulses transmitted from the switchboard over the voice line and ground E over the filter connection 1 are supplied to the rectifier bridge 17 and, rectified, to the photodiode 18. By means of the ignition of the photodiode 18, the phototransistor 19 is activated, and the thereby provided output signal affects the actuator 25 across the amplifier 6 and the OR circuit 24. The high frequency receiver circuit is not affected by the 50 Hz charge pulses. When a telephone subscriber fraudulently connects one of the two speech conductors a or b to earth E, in order to short-circuit the 50 Hz charge pulses and thereby prevent a reaction of the charge counter or cash register magnet, the symmetry transformer 4 ensures that this manipulation does not leads to the goal. Normally, the voltages induced in the secondary winding 4 2 which are caused by the currents circulating in the two equally sized primary windings 40 and 41 are cancelled, as these currents are constantly the same in both primary windings, but are oppositely directed. This symmetry, however, is disturbed when one of the speech conductors a or b is short-circuited
med jord E. I dette tilfelle frembringer en ankommende 50-Hz-gebyrpuls som følge av den nå herskende asymmetri i sekundærviklingen 42 en indusert spenning som, likerettet i likeretterbroen 43 og forsterket ved hjelp av transistoren 44, i lavfrekvens-mottakerkretsens utgangsledning 23 resulterer i et signal slik det også uten den nevnte manipulasjon normalt ville bli mottatt av mottakerkretsen med filterkoplingen 1, slik at manøverorganet 25 reagerer på riktig måte. with ground E. In this case, as a result of the now prevailing asymmetry in the secondary winding 42, an arriving 50-Hz charge pulse produces an induced voltage which, rectified in the rectifier bridge 43 and amplified by the transistor 44, in the output line 23 of the low-frequency receiver circuit results in a signal such as would normally be received by the receiver circuit with the filter connection 1, even without the aforementioned manipulation, so that the maneuvering device 25 reacts in the correct way.
Når den beskrevne mottakerkopling innbygges i en med høyfrekvens-telling arbeidende telefonledning, ankommer de opptredende høyfrekvens-gebyrpulser over høyfrekvensvekselen 2, transistoren 31, forsterkeren 32 og ELLER-koplingen 24 til manøverorganet 25, mens 50-Hz-mottakerkoplingen ikke påvirkes. When the described receiver coupling is built into a high-frequency counting working telephone line, the occurring high-frequency charge pulses arrive via the high-frequency converter 2, the transistor 31, the amplifier 32 and the OR coupling 24 to the maneuvering device 25, while the 50-Hz receiver coupling is not affected.
Mottakerkoplingen ifølge oppfinnelsen, som kan The receiver coupling according to the invention, which can
i in
innbygges hos enhver abonnent og^ethvert mynttelefonapparat, be built into every subscriber and every coin-operated telephone device,
er ikke begrenset til den beskrevne oppbygging av lavfrekvens- is not limited to the described structure of low-frequency
og høyfrekvens-mottakerkretsene, men tillater mange forskjellige koplingsvarianter. and the high-frequency receiver circuits, but allow many different connection variants.
Claims (6)
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CH1197177A CH622654A5 (en) | 1977-09-30 | 1977-09-30 |
Publications (1)
Publication Number | Publication Date |
---|---|
NO783303L true NO783303L (en) | 1979-04-02 |
Family
ID=4378612
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
NO783303A NO783303L (en) | 1977-09-30 | 1978-09-29 | RECEIVER CONNECTION FOR TELEPHONE FEE PULSE |
Country Status (9)
Country | Link |
---|---|
AT (1) | AT364392B (en) |
BE (1) | BE870158A (en) |
CH (1) | CH622654A5 (en) |
DE (1) | DE2833322A1 (en) |
DK (1) | DK432578A (en) |
FR (1) | FR2404975A1 (en) |
GB (1) | GB2005111A (en) |
NL (1) | NL7809721A (en) |
NO (1) | NO783303L (en) |
Families Citing this family (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR2551604B1 (en) * | 1983-09-06 | 1985-10-25 | Thomson Csf Mat Tel | TELEXING DEVICE FOR ELECTRONIC TELEPHONE TERMINAL |
JPS62220054A (en) * | 1986-03-20 | 1987-09-28 | Fujitsu Ltd | Receiver for charging signal of central office line trunk circuit |
GB8703066D0 (en) * | 1987-02-11 | 1987-03-18 | Gen Electric Co Plc | Signal converter unit |
FR2648655B1 (en) * | 1989-06-19 | 1995-08-18 | Alcatel Business Systems | SIGNAL DETECTOR, OF TELEPHONE TAX TYPE, PARTICULARLY FOR TELEPHONE TRUNK |
NL8902617A (en) * | 1989-10-23 | 1991-05-16 | Nederland Ptt | METHOD AND APPARATUS FOR CONNECTING ON THE ONE PART A DEVICE CONNECTED WITH AN EARTHED SYSTEM WITH AN EXTENSION OF A SINGLE OR MULTIPHASE ELECTRICITY NETWORK WITH RESPECT TO THE OTHER CONNECTION. CONNECTIONS THE SMALLEST IMPEDANCE TO EARTH. |
GB2266819A (en) * | 1992-05-07 | 1993-11-10 | British Telecomm | Pulse detection |
DE19502448C2 (en) * | 1995-01-26 | 1998-07-30 | Gramespacher Max H | Third-party use detector for connection to a telephone line |
Family Cites Families (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
BE550795A (en) * | 1955-09-20 | |||
DE1563825A1 (en) * | 1966-08-10 | 1970-05-14 | Stotz Kontakt Gmbh | Residual current circuit breaker |
DE1291797B (en) * | 1967-06-07 | 1969-04-03 | Siemens Ag | Circuit arrangement for toll counters trained as roll counters at stations in telecommunications, especially telephone systems |
CH532873A (en) * | 1971-06-21 | 1973-01-15 | Sodeco Compteurs De Geneve | Billing meters for telephone systems with automatic billing |
CH540616A (en) * | 1972-01-10 | 1973-08-15 | Sodeco Compteurs De Geneve | Circuit arrangement for a telephone charge indicator |
DE2337107C2 (en) * | 1973-07-20 | 1975-07-24 | Siemens Ag, 1000 Berlin Und 8000 Muenchen | Receiving device for alternating voltage pulses transmitted via telecommunications, in particular telephone lines, e.g. B. 16 kHz counting pulses |
BR7501017A (en) * | 1974-03-01 | 1975-12-02 | Ite Imperial Corp | CIRCUIT PROTECTIVE DEVICE |
IT1035674B (en) * | 1975-05-09 | 1979-10-20 | Ind Politecnica Meridionale Ip | MEMORIZING DEVICE AND FOR PRINTING THE CALLED TELEPHONE NUMBER AND RELATED SHOTS |
-
1977
- 1977-09-30 CH CH1197177A patent/CH622654A5/de not_active IP Right Cessation
-
1978
- 1978-07-21 AT AT0532078A patent/AT364392B/en not_active IP Right Cessation
- 1978-07-29 DE DE19782833322 patent/DE2833322A1/en not_active Withdrawn
- 1978-08-30 FR FR7825445A patent/FR2404975A1/en active Granted
- 1978-09-01 BE BE190215A patent/BE870158A/en not_active IP Right Cessation
- 1978-09-22 GB GB7837768A patent/GB2005111A/en not_active Withdrawn
- 1978-09-25 NL NL7809721A patent/NL7809721A/en not_active Application Discontinuation
- 1978-09-29 DK DK432578A patent/DK432578A/en not_active Application Discontinuation
- 1978-09-29 NO NO783303A patent/NO783303L/en unknown
Also Published As
Publication number | Publication date |
---|---|
ATA532078A (en) | 1981-03-15 |
FR2404975A1 (en) | 1979-04-27 |
BE870158A (en) | 1979-01-02 |
GB2005111A (en) | 1979-04-11 |
CH622654A5 (en) | 1981-04-15 |
AT364392B (en) | 1981-10-12 |
NL7809721A (en) | 1979-04-03 |
DK432578A (en) | 1979-03-31 |
DE2833322A1 (en) | 1979-04-12 |
FR2404975B1 (en) | 1982-06-25 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US4621170A (en) | Means of transmitting signals along a line while also providing a direct voltage source | |
US5903155A (en) | Method of measurement for fault-distance determination on a HVDC power transmission line having at least two lines connected in parallel | |
US4931893A (en) | Loss of neutral or ground protection circuit | |
NO173076B (en) | PROCEDURE AND DEVICE FOR LOCATING EARTH CIRCULATION OF A THREE PHASE NET WORKER | |
GB2094595A (en) | Power line communication system using the neutral and ground conductors of a residental branch circuit | |
US4622535A (en) | Receiving circuit for a data transmission system | |
GB1409287A (en) | Ground fault indicator device | |
NO783303L (en) | RECEIVER CONNECTION FOR TELEPHONE FEE PULSE | |
US4156884A (en) | Ground fault protection system for industrial power circuits | |
EP0287369B1 (en) | Remote disconnection and shortcircuiting apparatus | |
US3963963A (en) | Ground-fault detection system | |
AU2017206161B2 (en) | An arc fault detection arrangement for a DC electric bus | |
US4776007A (en) | Solid state trunk circuit | |
US5444377A (en) | Electronic trip device comprising a test device | |
SE308333B (en) | ||
US3749857A (en) | Cable testing device for long-distance cables, particularly for occupied cables | |
US5311587A (en) | Sensor circuit for telephone line | |
US4199664A (en) | Telephone line circuit | |
JPH0473827B2 (en) | ||
US2466079A (en) | Fault locator coil | |
SU1742927A1 (en) | Device for protection against one phase short-circuit to ground in a c network | |
JPH04188085A (en) | Discriminating system for ground of ac receptacle | |
JP3065815B2 (en) | Partial discharge detection method | |
US1511756A (en) | Electrical testing system | |
SU1252201A1 (en) | Device for ensuring electric safety in work on contact system |