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US1723524A - Electric circuit for central telephone offices - Google Patents

Electric circuit for central telephone offices Download PDF

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Publication number
US1723524A
US1723524A US250586A US25058628A US1723524A US 1723524 A US1723524 A US 1723524A US 250586 A US250586 A US 250586A US 25058628 A US25058628 A US 25058628A US 1723524 A US1723524 A US 1723524A
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US
United States
Prior art keywords
relay
electric circuit
contact
subscriber
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.)
Expired - Lifetime
Application number
US250586A
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English (en)
Inventor
Rosa Augusto
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.)
Individual
Original Assignee
Individual
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 Individual filed Critical Individual
Application granted granted Critical
Publication of US1723524A publication Critical patent/US1723524A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04Q—SELECTING
    • H04Q3/00—Selecting arrangements

Definitions

  • This invention relates to a circuit for automatic exchanges having a calling line finder, or for semi-automatic central offices, or for manually operated central offices requiring a preselection by the operator, wherein the line finders are made to work by means of a relay in common to a certain group of suscribers, this relay being connected to the lines of the subscribers of its group by the intermediary of a coil with two windings for each subscriber.
  • One of the windings of the coil has a very high resistance and one of its ends, which coincides with the end of the second winding, is connected to the first contact of the line finders and the connectors of the subscriber, the said common relay being connected to the other end of the high resistance winding, while the free end of the other winding of the coil is connected to the second contact of the line finders and connectors of the subscriber.
  • A indicates the telephonic apparatus of the subscriber and V and LN are respectively the line finders and the connectors of the apparatus.
  • B indicates a resistance and E is the relay belonging to the group of subscribers which comprises the apparatus A.
  • D is' the high resistance winding and C the low resistance winding, the coinciding ends of these two windings being connected to the first contact F of the line finders and connectors W and LW, while the other end of the resistance D is connected to the relay E and the other end of the resistance C is connected to the other contact I of the line finders and connectors.
  • G indicates a relay complex and H a time lag relay.
  • the relay E causes the line finders W belonging to the subscriber A to work and as soon as one of them has found the subscriber who is calling a circuit is set up from the battery through the resistance B, the apparatus A, the winding C, the first contact F on the line finder, the armature g of the relay G to the battery.
  • the relay G starts working, draws the armature 9 down, kills the line finder and remains thus attracted through the following circuit: from the battery through the resistance B, the apparatus A, the second contact I of the line finder, the armature g of the relay G which is down, referring to the diagram, and back to the battery.
  • the contact F and thus all the first contacts on the line finders ⁇ V and on the connectors LW of the apparatus A are directly switched onto the battery by the armature g and the relay E is thus deenergized.
  • the relay G therefore remains connected to the contact I by the time lag relay H.
  • This arrangement ensures the fall of the relay E as this relay will not be traversed by a current until after a second subscriber of the same group has been calling.
  • a second line finder cannot stop on the contact that is engaged, as its relay G would be short-circuited. connectors is connected directly to the battery so that there is no danger of the 9 engaged signal not appearing, and a rotating line finder does not produce any noise when passing over the contacts of a subscriber that is engaged.
  • An electric circuit for central telephonic oflices comprising the subscribers circuit, a common control relay for a group of subscribers and a coil with a high resistance and a low resistance winding arranged between the said circuit and the relay, the coinciding ends of the two windings being connected to the first contact of the line finders and connectors of the subscriber, while the other end of the high resistance winding is connected to the common relay and the other end of the low resistance winding is connected to the second contact of the line finders and connectors.
  • An electric circuit for central telephonic ofiices comprising the subscribers circuit, a common control relay for a group of suhscribers' and a 'coil with two windings arranged between' the said circuit and the f v ...r.. J. p D M relay, the common point-of the two windings being connected directly to the battery when 1 a line finder or connector has stopped on the position of the subscriber to whom the coil corresponds.

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  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Monitoring And Testing Of Exchanges (AREA)
  • Interface Circuits In Exchanges (AREA)
US250586A 1927-01-31 1928-01-30 Electric circuit for central telephone offices Expired - Lifetime US1723524A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
IT1723524X 1927-01-31

Publications (1)

Publication Number Publication Date
US1723524A true US1723524A (en) 1929-08-06

Family

ID=11434533

Family Applications (1)

Application Number Title Priority Date Filing Date
US250586A Expired - Lifetime US1723524A (en) 1927-01-31 1928-01-30 Electric circuit for central telephone offices

Country Status (3)

Country Link
US (1) US1723524A (xx)
GB (1) GB283971A (xx)
NL (1) NL30173C (xx)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2574224A (en) * 1945-09-03 1951-11-06 Roelof M M Oberman Circuit for marking a line as busy
US2657270A (en) * 1948-07-02 1953-10-27 Hartford Nat Bank & Trust Co Line circuit without relays
US2697750A (en) * 1949-01-17 1954-12-21 Hartford Nat Bank & Trust Co Relayless line finder circuit
US3156779A (en) * 1960-11-25 1964-11-10 Automatic Elect Lab Line finding arrangement

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2574224A (en) * 1945-09-03 1951-11-06 Roelof M M Oberman Circuit for marking a line as busy
US2657270A (en) * 1948-07-02 1953-10-27 Hartford Nat Bank & Trust Co Line circuit without relays
US2697750A (en) * 1949-01-17 1954-12-21 Hartford Nat Bank & Trust Co Relayless line finder circuit
US3156779A (en) * 1960-11-25 1964-11-10 Automatic Elect Lab Line finding arrangement

Also Published As

Publication number Publication date
GB283971A (en) 1929-07-22
NL30173C (xx)

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