US2345046A - Intercommunicating system - Google Patents

Intercommunicating system Download PDF

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Publication number
US2345046A
US2345046A US434339A US43433942A US2345046A US 2345046 A US2345046 A US 2345046A US 434339 A US434339 A US 434339A US 43433942 A US43433942 A US 43433942A US 2345046 A US2345046 A US 2345046A
Authority
US
United States
Prior art keywords
stations
station
line
conductors
transmitter
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
US434339A
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English (en)
Inventor
Roswell H Herrick
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.)
Automatic Electric Laboratories Inc
Original Assignee
Automatic Electric Laboratories Inc
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
Priority to NL66226D priority Critical patent/NL66226C/xx
Priority to BE467440D priority patent/BE467440A/xx
Application filed by Automatic Electric Laboratories Inc filed Critical Automatic Electric Laboratories Inc
Priority to US434339A priority patent/US2345046A/en
Application granted granted Critical
Publication of US2345046A publication Critical patent/US2345046A/en
Priority to FR938320D priority patent/FR938320A/fr
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04M—TELEPHONIC COMMUNICATION
    • H04M11/00—Telephonic communication systems specially adapted for combination with other electrical systems
    • H04M11/02—Telephonic communication systems specially adapted for combination with other electrical systems with bell or annunciator systems
    • H04M11/025—Door telephones
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04M—TELEPHONIC COMMUNICATION
    • H04M9/00—Arrangements for interconnection not involving centralised switching
    • H04M9/001—Two-way communication systems between a limited number of parties
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04M—TELEPHONIC COMMUNICATION
    • H04M9/00—Arrangements for interconnection not involving centralised switching
    • H04M9/002—Arrangements for interconnection not involving centralised switching with subscriber controlled access to a line, i.e. key telephone systems

Definitions

  • the present invention relates to telephone systems and more particularly to improvements in intercommunicating telephone and signaling systems of the type in which a loudspeaker is employed at a main or master station, and the usual telephone instrument is used at each subordinate station.
  • a separate and direct battery feed circuit to the master station transmitter which utilizes one of the voice transmission conductors and one of the signaling conductors of the line interconnecting the stations.
  • an improved. arrangement is provided for separating the battery feed circuits from the voice current transmission circuits in order to reduce the losses in the voice current transmission circuits.
  • the transmission of the return signal to the master station is dependent upon the operation of the signal device provided at the station being signaled from the master station.
  • the intercommunicating system there illustrated comprises a 3 master station A and two subordinate stations 3 and C, the three stations being interconnected by a four conductor line 22.
  • the system may, if desired, be used to provide communication facilities between the lobby and the several apartments of an apartment building, in which case the equipment of the master station A is located in the lobby of the building and the stations B and C are located in two different apartments of the building.
  • the system may be used to provide communication iacilities between the oiilce of a business executive and the desks of his assistants.
  • the equipment provided at the master station A comprises a transmitter II. a loudspeaker 15, a pair of coupling condensers l6 and H, a pair of coupling transformers l2 and IS, a current limiting resistor l0. and a call switch ll.
  • Each of the subordinate stations comprises a handset including a transmitter and a receiver 3
  • the system further comprises a transformer which is common to the subordinate stations, and a battery 34 which is connected to supply energizing current to the transmitters provided at the several stations- Separate channels are used for transmitting voice currents to and from the master station A. More p ifi ly.
  • the first and second conductors 24 and 25 of the line 22 define a channel for transmitting voice currents to the master station from a called subordinate station, and the second and third conductors 25 and 26 define a second channel for transmitting voice currents to a called subordinate station from the master station.
  • the first conductor 24 is also used in conjunction with the fourth conductor 23 to provide a circuit for controlling the buzzers 33b, 33c, etc.. from the master station.
  • the fourth conductor 23 is also used in combination with the second conductor 25 to provide a circuit for energizing the transmitter l8 provided at the master station.
  • a call intended for the subordinate station B is initiated at the master station A.
  • code signaling is utilized selectively to signal the different subordinate stations.
  • a circuit is completed for energizing the signal buzzers33a, 331), etc., in multiple, this circuit extending from the positive terminal of the battery 34 by way 'of the winding 31, the conductor 24, the contacts of the switch II, the conductor 23, the contacts 38b, 380, etc.. and the windings of the buzzers 33b, 330, etc.. in multiple to the negative terminal of the battery 34.
  • the buzzers operate to signal the subordinates at the stations B, C, etc. Since, however, the switch II is operated in accordance with the code designating the station B, only this station will answer the call.
  • the buzzers l2 operate, the contacts 38 thereof are intermittently opened to interrupt the current flow through the winding 31 of the transformer 35.
  • the pulsating current thus caused to fiow through the winding 21 of the transformer 25 causes a corresponding alternating voltage to be developed by induction in the winding 30 of the transformer 35.
  • the voltages appearing across the windings 36 and 31 are impressed across the transformer winding IS over a circuit which includes the battery 34, the transmitters 30 in parallel, the first and second line conductors 24 and 25 and the condenser IS.
  • the resulting alternating current fiow through the winding l3 causes a corresponding alternating voltage to be induced in the winding ll which is reproduced by the loudspeaker as an audible return signal tone.
  • circuits are completed for energizing the transmitters 30 and it, that for energizing the transmitter l8 extending from. the positive terminal of the battery 34, by way of the contacts 32b, the second line conductor 25, the transmitter l8, the winding 20, the current limiting resistor ID, the fourth line conductor 23, the contacts 38 and the windings of the buzzers 23 in parallel to the negative terminal of battery, and that for energizing the transmitter 30b including the transformer winding 38 and the contacts of the switch 32b.
  • the signal current transmission channels as described above do not include amplifiers, the greatest possible efliciency is required to obtain an adequate loudspeaker volume from the signal currents supplied by the transmitters provided at the subordinate stations, and also to obtain adequate handset receiver volume from the master station transmitter l 8 when it is required that this transmitter shall respond to sound waves originating at points two or three feet removed therefrom.
  • the impedances between the various connected elements are carefully matched and the line losses are held to a minimum. I
  • the purpose of-providing the line conductor 23 separate from the voice current transmission channels is not alone to provide a simple signaling circuit, but also to keep direct current from traversing the handset receivers 3
  • the voice frequency currents produced by the transmitter l8 may be confined within the closed low impedance circuit including the primary winding of the transformer I9 and the condenser II.
  • the voice frequency currents developed incident to operation of the transmitter l8 are not dissipated as direct current line losses, as would be the case if the battery feed and voice current transmission circuits were not separated. In this regard.
  • the resistor It has the function of reducing the magnitude of the current supplied to the transmitter l8 from the battery 34 to a value which is substantially less than that of the current supplied to the transmitter 30b, for example, as provided at the subordinate station B.
  • the latter transmitter may require a normal operating current of approximately 150 milliamperes to provide the requisite output for satisfactory operation of the loudspeaker l5, whereas the optimum current for the remote pickup transmitter l8 provided at the master station A is about '75 milliamperes.
  • a pair of stations each including transmitter and receiver elements, a four conductor line extending between said stations, the first and second conductors of said line defining a signal channel for transmitting signal currents between said stations in one direction, the second and third conductors of said line defining a second signal channel for transmitting signal currents between said stations in the other direction, and the second and fourth conductors of said line defining a circuit for energizing the transmitter provided at one of said stations.
  • a pair of stations each including transmitter and receiver elements, a four conductor line extending between said stations, the first and second conductors of said line defining a signal channel for transmitting signal currents between said stations in one direction, the second and third conductors of said line defining a sec-' ond signal channel for transmitting signal currents between said stations in the other direction, and the second and fourth conductors of said line defining a normally incomplete circuit for energizing the transmitter provided at one of said stations, and means at the other of said stations for completing said circuit.
  • a pair of stations each including transmitter and receiver elements, a 1ine connecting said stations and including at least four conductors, the first and second conductors of said line defining a channel for transmitting signal currents between said stations in one direction, the second and third conductor of said line defining a channel for transmitting signal currents between said stations in the oppostie direction, a signal device at one of said stations controllable over the first and fourth conductors from the other of said stations to produce a signal indication and to produce a return signal voltage, means including the first and second conductors of said line for impressing said voltage across the terminals of the receiving element provided at said other station, a normally incomplete circuit including the second and fourth conductors of said line for energizing the transmitter provided at said other station, and means at said one station for completing said circuit.
  • a pair of stations each including transmitter and receiver elements, a line connecting said stations and including at least four conductors, the first and second conductors of said line defining a channel for transmitting signal currents between said stations in one direction, the second and third conductors of said line defining a channel for transmitting "signal currents between said stations in the opposite direction, a signal device at one of said stations controllable over the first and fourth conductors from the other of said stations to produce a signal indication and to produce a return signal voltage, means including the first and second conductors of said line of the receiving element provided at said other station, a normally incomplete circuit including the second and fourth conductors of said line for energizing the transmitter provided at said other station, a normally incomplete circuit for energizing the transmitter provided at said one station, and a switch at said one station operative to complete both of said circuits.
  • a pair of stations each including transmitter and receiver elements, a line connecting said stations and including at least four conductors, the first and second conductors of said line defining a channel for transmitting signal currents between said stations in one direction, the second and third conductors of said line defining a second channel for transmitting signal currents between said stations in the opposite direction, a buzzer provided at one of said stations and controllable over the first and fourth conductors of said line from the other of said stations to produce an audible signal and to produce a return signal voltage, and means including the first and second conductors of said line for impressing said return signal voltage across the terminals of the receiving element provided at said other station.
  • a pair of station each including transmitter and receiver elements, a line connecting said stations to provide two separate signaling channels one of which couples the transmitter element at one of said stations to the receiver element at the other of said-stations and the other of which couples the transmitter element at the other of said stations to the receiver element at said one station, a buzzer at said one station controllable over said line from said other station to produce an audible signal and to produce a return signal voltage, and means for impressing said return signal voltage on said one channel.
  • a pair of stations a line connecting said stations to provide a signaling channel therebetween, a buzzer at one of said stations controllable over said line from the other of said stations to produce an audible signal and to produce a return alternating current signal voltage, and means for impressing said return alternating current signal voltage on said channel.
  • a pair of stations 9. line connecting said stations to provide a signaling channel therebetween, a signal device at one of said stations controllable over said line from the other of said stations to produce a signal indication and to produce a return alternating current signal voltage, and means for impressing said return alternating current signa1 voltage on said signaling channel.

Landscapes

  • Engineering & Computer Science (AREA)
  • Signal Processing (AREA)
  • Interconnected Communication Systems, Intercoms, And Interphones (AREA)
US434339A 1942-03-12 1942-03-12 Intercommunicating system Expired - Lifetime US2345046A (en)

Priority Applications (4)

Application Number Priority Date Filing Date Title
NL66226D NL66226C (enrdf_load_stackoverflow) 1942-03-12
BE467440D BE467440A (enrdf_load_stackoverflow) 1942-03-12
US434339A US2345046A (en) 1942-03-12 1942-03-12 Intercommunicating system
FR938320D FR938320A (fr) 1942-03-12 1946-08-19 Dispositif d'intercommunication

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US434339A US2345046A (en) 1942-03-12 1942-03-12 Intercommunicating system

Publications (1)

Publication Number Publication Date
US2345046A true US2345046A (en) 1944-03-28

Family

ID=23723823

Family Applications (1)

Application Number Title Priority Date Filing Date
US434339A Expired - Lifetime US2345046A (en) 1942-03-12 1942-03-12 Intercommunicating system

Country Status (4)

Country Link
US (1) US2345046A (enrdf_load_stackoverflow)
BE (1) BE467440A (enrdf_load_stackoverflow)
FR (1) FR938320A (enrdf_load_stackoverflow)
NL (1) NL66226C (enrdf_load_stackoverflow)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2606252A (en) * 1945-03-29 1952-08-05 Hartford Nat Bank & Trust Co Loud-speaking telephone arrangement

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2606252A (en) * 1945-03-29 1952-08-05 Hartford Nat Bank & Trust Co Loud-speaking telephone arrangement

Also Published As

Publication number Publication date
BE467440A (enrdf_load_stackoverflow)
FR938320A (fr) 1948-09-10
NL66226C (enrdf_load_stackoverflow)

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