GB1386193A - Ringing trip circuit - Google Patents

Ringing trip circuit

Info

Publication number
GB1386193A
GB1386193A GB507973A GB507973A GB1386193A GB 1386193 A GB1386193 A GB 1386193A GB 507973 A GB507973 A GB 507973A GB 507973 A GB507973 A GB 507973A GB 1386193 A GB1386193 A GB 1386193A
Authority
GB
United Kingdom
Prior art keywords
transistor
resistor
diode
ring trip
feb
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.)
Expired
Application number
GB507973A
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.)
International Standard Electric Corp
Original Assignee
International 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 International Standard Electric Corp filed Critical International Standard Electric Corp
Publication of GB1386193A publication Critical patent/GB1386193A/en
Expired legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04M—TELEPHONIC COMMUNICATION
    • H04M19/00—Current supply arrangements for telephone systems
    • H04M19/02—Current supply arrangements for telephone systems providing ringing current or supervisory tones, e.g. dialling tone or busy tone
    • H04M19/026—Arrangements for interrupting the ringing current

Landscapes

  • Engineering & Computer Science (AREA)
  • Signal Processing (AREA)
  • Interface Circuits In Exchanges (AREA)
  • Devices For Supply Of Signal Current (AREA)

Abstract

1386193 Automatic exchange systems INTERNATIONAL STANDARD ELECTRIC CORP 1 Feb 1973 [8 Feb 1972] 5079/73 Heading H4K A ring trip circuit includes a resistor R1 connected in a wire of a subscriber's line, the potential across the resistor being coupled to the base of a transistor T1 via a low pass filter F, and the arrangement is such that ringing current alone flowing in resistor R1 is prevented from triggering transistor T1 due to the filter F whereas a direct current flowing in resistor R1 causes transistor T1 to turn on, thereby operating ring trip relay O. Diode Di1 is a threshold diode used to protect transistor T1 against excess line voltages and diode Di2 prevents reverse currents in the collector-base junction of transistor T1. More particularly transistor T1 is turned on when the combination of direct current and ringing current in resistor R1 makes terminal A1 negative to charge capactior C3, thereby turning on transistor T2. When terminal A1 positive, transistor T1 turns off, capacitor C3 discharges the keeping transistor T2 conducting and in turn causing transistor T3 to conduct and operate the ring trip relay O.
GB507973A 1972-02-08 1973-02-01 Ringing trip circuit Expired GB1386193A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
FR7204108A FR2171594A5 (en) 1972-02-08 1972-02-08

Publications (1)

Publication Number Publication Date
GB1386193A true GB1386193A (en) 1975-03-05

Family

ID=9093144

Family Applications (1)

Application Number Title Priority Date Filing Date
GB507973A Expired GB1386193A (en) 1972-02-08 1973-02-01 Ringing trip circuit

Country Status (3)

Country Link
DE (1) DE2305594B2 (en)
FR (1) FR2171594A5 (en)
GB (1) GB1386193A (en)

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
SE7512060L (en) * 1974-11-07 1976-05-10 Western Electric Co DEVICE FOR PATRICATING AND DETECTING RING SIGNALS OVER A CALLED LINE IN A TELECOMMUNICATION SYSTEM
DE3001497C2 (en) * 1980-01-17 1981-11-26 Telefonbau Und Normalzeit Gmbh, 6000 Frankfurt Circuit arrangement for recognizing the subscriber message in telephone switching systems
US4447675A (en) * 1982-10-29 1984-05-08 Bell Telephone Laboratories, Incorporated Ring-trip detector

Also Published As

Publication number Publication date
FR2171594A5 (en) 1973-09-21
DE2305594B2 (en) 1976-10-21
DE2305594A1 (en) 1973-08-16

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Legal Events

Date Code Title Description
PS Patent sealed
435 Patent endorsed 'licences of right' on the date specified (sect. 35/1949)
732 Registration of transactions, instruments or events in the register (sect. 32/1977)
PCNP Patent ceased through non-payment of renewal fee