FR2434529A1 - Electronic circuit connected in telephone line - prevents fraudulent use of line by monitoring line current and shorting line in preset circumstances - Google Patents

Electronic circuit connected in telephone line - prevents fraudulent use of line by monitoring line current and shorting line in preset circumstances

Info

Publication number
FR2434529A1
FR2434529A1 FR7824258A FR7824258A FR2434529A1 FR 2434529 A1 FR2434529 A1 FR 2434529A1 FR 7824258 A FR7824258 A FR 7824258A FR 7824258 A FR7824258 A FR 7824258A FR 2434529 A1 FR2434529 A1 FR 2434529A1
Authority
FR
France
Prior art keywords
line
telephone
electronic circuit
circumstances
preset
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
FR7824258A
Other languages
French (fr)
Other versions
FR2434529B3 (en
Inventor
Pierre Le Buhan
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.)
APP AUTOMATIQUES STE FSE
Original Assignee
APP AUTOMATIQUES STE FSE
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 APP AUTOMATIQUES STE FSE filed Critical APP AUTOMATIQUES STE FSE
Priority to FR7824258A priority Critical patent/FR2434529A1/en
Publication of FR2434529A1 publication Critical patent/FR2434529A1/en
Application granted granted Critical
Publication of FR2434529B3 publication Critical patent/FR2434529B3/fr
Granted legal-status Critical Current

Links

Classifications

    • 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)
  • Computer Security & Cryptography (AREA)
  • Signal Processing (AREA)
  • Prepayment Telephone Systems (AREA)

Abstract

A telephone set (2) is coupled through two conductors (11, 10) through payment recorded devices (12, 20, 21) to a central station. A fraud prevention electronic circuit (1) is connected in the second line, at earth potential, between the set (1) and recorded device (21) while the first line, at for example -48v, includes a line switch (13). When a call is connected, line current flow, through a diode (CR1) in the second line the voltage drop across which inhibits a transistor detection circuit (DI) in the electronic circuit (1). The detection circuit maintains non-conductive through a Darlington amplifier (AP), a thyristor (Th1) connected across the conductors. An attempt to use the telephone fraudulently by earthing its microphone terminal (6, 7, 8) turns off the diode (CR1) which triggers the thyristor (Th1) to short-circuit the telephone time.
FR7824258A 1978-08-21 1978-08-21 Electronic circuit connected in telephone line - prevents fraudulent use of line by monitoring line current and shorting line in preset circumstances Granted FR2434529A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
FR7824258A FR2434529A1 (en) 1978-08-21 1978-08-21 Electronic circuit connected in telephone line - prevents fraudulent use of line by monitoring line current and shorting line in preset circumstances

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
FR7824258A FR2434529A1 (en) 1978-08-21 1978-08-21 Electronic circuit connected in telephone line - prevents fraudulent use of line by monitoring line current and shorting line in preset circumstances

Publications (2)

Publication Number Publication Date
FR2434529A1 true FR2434529A1 (en) 1980-03-21
FR2434529B3 FR2434529B3 (en) 1981-05-22

Family

ID=9211965

Family Applications (1)

Application Number Title Priority Date Filing Date
FR7824258A Granted FR2434529A1 (en) 1978-08-21 1978-08-21 Electronic circuit connected in telephone line - prevents fraudulent use of line by monitoring line current and shorting line in preset circumstances

Country Status (1)

Country Link
FR (1) FR2434529A1 (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0417979A2 (en) * 1989-09-15 1991-03-20 Mars Incorporated Method and apparatus for preventing pay telephone fraud and reducing handset vandalism
EP0727898A1 (en) * 1995-02-10 1996-08-21 Landis & Gyr Technology Innovation AG Telephone station
US5864618A (en) * 1995-02-10 1999-01-26 Electrowatt Technology Innovation Ag Telephone set having an anti-fraud arrangement which prevents any fraudulent attempt to the telephone
NL1006183C2 (en) * 1996-05-31 1999-07-13 Lucent Technologies Inc Method and device for preventing pen fraud in coin telephones using voltage reversal pulses to measure the costs.

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0417979A2 (en) * 1989-09-15 1991-03-20 Mars Incorporated Method and apparatus for preventing pay telephone fraud and reducing handset vandalism
EP0417979A3 (en) * 1989-09-15 1992-05-13 Mars Incorporated Method and apparatus for preventing pay telephone fraud and reducing handset vandalism
EP0727898A1 (en) * 1995-02-10 1996-08-21 Landis & Gyr Technology Innovation AG Telephone station
US5864618A (en) * 1995-02-10 1999-01-26 Electrowatt Technology Innovation Ag Telephone set having an anti-fraud arrangement which prevents any fraudulent attempt to the telephone
NL1006183C2 (en) * 1996-05-31 1999-07-13 Lucent Technologies Inc Method and device for preventing pen fraud in coin telephones using voltage reversal pulses to measure the costs.

Also Published As

Publication number Publication date
FR2434529B3 (en) 1981-05-22

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