US2317191A - Telephone system - Google Patents

Telephone system Download PDF

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Publication number
US2317191A
US2317191A US375713A US37571341A US2317191A US 2317191 A US2317191 A US 2317191A US 375713 A US375713 A US 375713A US 37571341 A US37571341 A US 37571341A US 2317191 A US2317191 A US 2317191A
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United States
Prior art keywords
relay
relays
channel
operated
digit
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
US375713A
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English (en)
Inventor
Bernard D Holbrook
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.)
AT&T Corp
Original Assignee
Bell Telephone 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
Application filed by Bell Telephone Laboratories Inc filed Critical Bell Telephone Laboratories Inc
Priority to US375713A priority Critical patent/US2317191A/en
Priority to FR887178D priority patent/FR887178A/fr
Priority to DEST61351D priority patent/DE745935C/de
Priority to GB2394/42A priority patent/GB551431A/en
Application granted granted Critical
Publication of US2317191A publication Critical patent/US2317191A/en
Priority to NL70302D priority patent/NL70302C/nl
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04Q—SELECTING
    • H04Q1/00—Details of selecting apparatus or arrangements
    • H04Q1/18—Electrical details
    • H04Q1/30—Signalling arrangements; Manipulation of signalling currents
    • H04Q1/44—Signalling arrangements; Manipulation of signalling currents using alternate current
    • H04Q1/444—Signalling arrangements; Manipulation of signalling currents using alternate current with voice-band signalling frequencies
    • H04Q1/45—Signalling arrangements; Manipulation of signalling currents using alternate current with voice-band signalling frequencies using multi-frequency signalling
    • H04Q1/453—Signalling arrangements; Manipulation of signalling currents using alternate current with voice-band signalling frequencies using multi-frequency signalling in which m-out-of-n signalling frequencies are transmitted
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04Q—SELECTING
    • H04Q3/00—Selecting arrangements
    • H04Q3/42—Circuit arrangements for indirect selecting controlled by common circuits, e.g. register controller, marker

Definitions

  • This invention relates to telephone systems and more particularly to receiving equipment operably connectable with or forming an integral part of a transmission line over which alternating current signals, preferably within Voice frequency range, are transmitted for effecting the operation of said equipment which may be used, in turn, to control the selective positioning of switching apparatus. More particularly, the invention has to do with a code translating circuit for the receiving equipment of a telephone system of the type disclosed, for instance, in the copending application of G. Hecht and A. A. Lundstrom Serial No. 355,712, filed September "I, 1940.
  • a telephone system of the type in which automatic switches are controlled by means responsive to alternating currents of different frequencies generated at a subscribers station and transmitted over a line terminating in a plurality of channel detectors each selectively tuned to a different one of the signal frequencies and responsive thereto to operate a relay which, in combination with a relay operated over another channel detector responsive to a current of another signal frequency in the same signal impulse, serves to function a settable register, or sender, in which is locked-in a record of the digit indicated by the two operated relays; that is, by the two frequencies in the pulse transmitted from the subscribers station.
  • the signal impulses comprise different combinations of frequencies to which the separate channel detectors are respectively tuned to respond and for which a relay or the like is energized for each frequency l" in the impulse to temporarily register the digit or character designated by the impulse, it is often necessary to change such registration into a setting equivalent to that which would be produced, say, by a number of direct current impulses indicated by the original alternating current impulse.
  • the area itself may be enlarged by the incorporation therein of telephone lines which are adapted to transmit wanted designations by alternating current frequency impulses of the kind indicatedv above, and the register senders will have to be modified to receive the new impulses on special registers adapted for the purpose.
  • the direct current impulse registers are then operated to take the same setting they would have taken had they been operated in response to a station dial by the num- CIK ber of direct current impulses indicated by the one alternating current frequency impulse.
  • Line extending switches are then controllably positioned by the direct current impulse registers.
  • Decoding circuits by which a given register code is changed into another code are, of course, old in the signaling arts, such circuits usually comprising auxiliary relay and electronic tube devices intermediate the two registers for effecting the translation. In the present invention, however, no auxiliary devices of any kind are used between the two registers, the translation being effected by the channel vrelays of the alternating current impulse register when operating directly in response to the signal frequencies that activate the corresponding detectors of the register. In this manner considerable economy of apparatus is obtained.
  • one feature of the invention is a relay in each channel which is operatively associated therewith and with one or more corresponding relays in other channels whereby their operation, in the combination required by the frequencies in an alternating current impulse designating a digit or character, activates one or more of a group of conductors intermediate the frequency impulse register and the direct current register by means of which the latter is set to register the digit designated by the frequencies in the impulse which caused the operation of the channel relays of the alternating current impulse register.
  • the decoding circuit is self-proving; that is, will fail to activate the required conductors connecting with the register to be set if the number of channel relays operated is more or less than the precise number called for by any digit or character indicated by the transmitted alternating current impulse and further provides in such an event a suitable alarm that will direct attention to the failure. It is assumed, of course, that each signaling impulse designating a digit or character will always have the same number of frequencies in accordance with whatever signaling code is used, albeit the frequencies themselves will be present in the different combinations required by the code for each different digit or character.
  • Fig. 1 shows schematically certain elements of the telephone system more completely disclosed in Patent 2,237,742, issued to A. A. Lundstrom on April 8, 1941, and in which certain other elements diierent frequencies, preferably in the voice frequency range, in response to the depression of.
  • 02 represents a line extending from the station instrument to the central ofiice whence', through one of a plurality of selectable sender connectors I
  • Each channel includes a band-pass filter (not shown), a detector amplifier tube and a relay such as relay A, for example, in the anode circuit'thereof which operates when the tube is rendered conductive by the ap- -plication thereto of the signal current carried by the frequency in the signal for which the bandpass iilter of the channel is adapted to pass.
  • 30 is operatively associated with all the channels through conductors 2, 4, and Z, each of said conductors connecting, respectively on the channel side, with the channel relays in the manner shown-in the drawing and, on the register side, with a relayor other electromagnetic device (not shown) which is adapted for operative response whenever a potential is applied to its associated conductor.
  • 30 is indicated only in its most generalized form as it is evident that it can' be of any suitable design adapted for setting in response, say, to the setting of another register which responds to a train of direct current impulses transmitted over the subscribers line and connected thereto by a ⁇ group of conductors identical to conductors I--Z shown in Fig. 1 and thus provide an identical setting for completely disclosed in the above-mentioned patent to A.
  • a call is initiated at station X by the removal of the station instrument from the switchhook whereupon the the same digit or character, by the activation of k conductors l-Z in the combination called for by an entirely different code.
  • 30 may, for instance, take the form of the registers of the sender shown and described in Patent 1,862,549 granted to R. Raymond and W. J. Scully on June 14, 1932 in which event it would comprise a group of register relays connectible to conductors I-Z through a plurality of appropriate transfer devices which would be controlled over conductor I
  • any other switching medium settable over conductor I-Z in accordance with a dened code will be equally appropriate, and it is understood thatno limitation is intended for my invention by reference to the above sender or any other form of switching device or devices operable over conductors I-Z and other conductors as explained hereinafter.
  • 09 and the volume limiter III are commercially available circuit units while the channels ja-fe, except for the modification in the use of relays A-E and their interrelated circuits for activating conductors I-Z are line is then extended by any suitable means to the central oice at lwhich an available sender is then connected to said line through the medium of the sender connector I I3, after which key tone is transmitted 4back to the calling station X by circuits not shown, as a signal that the sending device IOI may be operated to transmit lthe number of the wanted station Y, all in the manner described in the above-mentioned Ipatent to A. A. Lundstrom.
  • the current composed of the two frequencies is induced inthe secondary winding of transformer
  • volume limiter III Considering that portion of the signal energy which passes into the volume limiter I
  • the reason for doing this is, of course, to prevent overloading any of the channel detectors which, should such overloading occur inv the event of a heavy input signal due, say, to a very short loop
  • adjusting the volume limiter III to a suitable level of output energy above the operate level of the channel detectcrs, false operation of adjoining channels upon heavy signal currents is avoided.
  • the energy output from the volume limiter I I I ⁇ f is applied, through transformer
  • 355.712 filed September 7, 1940 and comprises a timing circuit the essential function of which is to operate relay IZ a predetermined interval after the arrival of the signal impulse and to keep it operated for a predetermined interval thereafter during which interval ground is applied to conductor H and, therethrough to the cathodes of the channel detectors ,ia-fe in order to sensitize them for response to the incoming signal.
  • the enabler i i@ is no part of the invention except in so iai' as it is an element used tc activate the detector tubes of the channels if they are not normally activated, and for which piu'- pose any other suitable element will do, the enabler is neither shown nor described in detail, reference being had to the above-mentioned ccpending application Serial No. 355,712 for a detailed showing and description thereof.
  • the tubes of the channels involved for the frequencies transmitted operate to cause current to flow through their re- ⁇ spective anode circuits whereby the relays in the group of relays A-E of the activated channels Will operate.
  • the relays in the group of relays A-E of the activated channels Will operate.
  • 30 according to its code as above indicated is that two and only two channels will have been activated and, therefore, that their corresponding relays will have operated.
  • a failure to operate only two channel relays will cause a failure of registration and will further cause an alarm signal to be transmitted to a register to indicate the fact.
  • the capital letter within each rectangle identifies a particular relay, and the small letter alongside a set of contacts identifies a set of contacts on the relay bearing the capital letter designation, while the front and back contacts of the relavs are distinguished by the absence or presence, respectively, of a prime on the identifying letter.
  • a contact marked (e) is a front contact on relay E, one marked (e') a back contact on the same relay.
  • Other circuit elements are shown in usual form. With these few conventions understood, the schematic is followed without difculty.
  • the other two cases are distinguished by the alarm relay W.
  • This is a slow-operate relay with its winding in parallel with a front contact of relay N in the common looking conductor of the ve channel relays.
  • the resistance y in each individual locking conductor may be required to make up for the voltage drop through the electronic detector, if the drop is large enough to warrant it.
  • the front contact of ⁇ relay T being closed as explained hereinafter, any channel relays that operate will lock through the winding of relay W to off-normal ground. If just two channel relays operate (which is thesecond condition), relay N will operate before relay W, will close its front contact and will short out the winding of said relay W. The channel relays will then remain locked through the front contacts of relays N and T.
  • relay N If any other number of channel relays operate (which is the third condition), say, either one or more than two, relay N will not operate inasmuch as it is only possible to close its circuit through the front contacts of two operated channel relays and the back contacts of three unoperated ones as previously explained. In thisv case the winding of relay W will not be short-circuited, and this relay will operate and, with the operated channel relays, will remain locked through the front contact of relay T.
  • the front'contact w of relay W grounds the alarm conductor
  • the timing features are provided by the slow release characteristics of relays T and R. Arranged as shown they will operate fast, but their release will be delayedby 'times which are controlled through the separate condenser-resistance circuit associated with each of them.
  • the releasing time of relay R is made greater vthan thatof relay T by the appropriate choice of the constants of resistance
  • timing action The details of the timing action are most easily explained by following the action of the entire circuit through the seizure of the sender and the reception and registration of one digit.
  • the seizure of the sender causes off-normal ground to be applied in any suitable manner to conductor
  • Relay R then operates through the other back contact of relay N (left outer back contact, see Fig. 1) and the front Contact t of relay T. Since relay T operates before relay R, its back contact t opens the ground path to the transfer conductor IIS before the front contact of relay R closes. If no channel relays operate, the cir- 'cuit will remain in this vcondition until offvent its reapplication immediately after removal.
  • relays T and R operated by off-normal ground on conductor
  • relay N The extension of ground to the point P also operates the relay N as previously explained, When this relay operates, one of its front contacts short-circuits the winding of the slowoperate relay W, which has not yet had time to come up, preventing its subsequent operation but maintaining the locking circuits of the operated channel relays A and C.
  • the other front Contact of relay N connectsrthe secondary winding of relay N to the transfer conductor IIS which is, however, not yet grounded because relay T is operated and, therefore, contact t is open.
  • the channel relays A and C then release, removing groundfrom the register conductors l and 2 and also from the primary winding of relay N.
  • the required overlap of the grounds on the register conductors l-Z and on the transfer conductor H9 is obtained by the release time of the fastest releasing channel relay.
  • relay T Upon the release of relay R (after the release of relay T) ground is removed from the transfer conductor I I9 and from the secondary winding of relay N which accordingly releases in turn.
  • relay T again operates, relay R, then reoperates through the front contact of relay T, and the circuit is restored to its original condition and is ready to respond to further operations of the channel relays.
  • the operation of relay T through a back Contact of relay N insures the complete restoration of the circuit when relay R releases.
  • a sender therefor which is adapted for the registration of wanted designations, comprising a plurality of channel detectors each adapted to pass a specific frequency therethrough cf a plural frequency pulsev designating a digit or character, a relay in each channel detector responsive to the frequency passed through said channel detector, and a plurality of conductors selectively activated singly or in combination by an invariable number of said relays when operated, to indicate the digit or character designated by the number of frequencies in said plural frequency pulse.
  • a sender therefor which is adapted for the registration of wanted designations, comprising a plurality of channel detectors each adapted to pass a specific frequency therethrough of a plural frequency pulse designating a digit or character, a relay in each channel detector responsive to the frequency passed through said channel detector, and a plurality of conductors selectively activated singly or in combination by an invariable number of said relays when operated and an invariable number of other of said relays concurrently unoperated to indicate a digit or character designated by the number of frequencies in said plural frequency pulse.
  • a sender therefor which is adapted for the registration of wanted designations, comprising rive channel detectors each adapted to pass a specific frequency therethrough of a two-frequency pulse designating a digit or character, a relay in each channel detector responsive to the frequency passed through said channel detector, and a plurality of conductors selectively activated vsingly or in combination by two of said relays when operated and three other of said relays concurrently unoperated to indicate a digit or character designated by the two frequencies in said two-frequency pulse.
  • a sender therefor which is adapted for the registration of wanted designations, comprising five channel detectors each adapted to pass a specific frequency therethrough of a two-frequency pulse designating a digit or character, a relay equipped with front and back contacts in each channel detector responsive to the frequency passed through said channel detector, a plurality of conductors selectively activated singly or in combination through the front contacts of two of said relays when operated and the back contacts of-three other of said relays concurrently unoperated to indicate a digit or character designated by the two frequencies in said two-frequency pulse.
  • a sender therefor which is adapted for the registration of a wanted designation, comprising a plurality of channel detectors each adapted to pass a specific fre-- quency therethrough of a plural frequency pulse designating a digit or character, a relay in each channel detector responsive to the frequency passed through said channel detector, a plurality of conductors selectively activated singly or in combination by an invariable number of said relays when operated to indicate the digit or character designated by the number of frequencies in said plural frequency pulse, and an alarm device responsive to the operation of'more than said invariable number of relays.
  • a sender therefor which is adapted for the registration of wanted designations, comprising a plurality of channel detectors each adapted to pass a specific frequency therethrough of a plural frequency pulse designating a digit or character, a relay in each channel detector responsive to the frequency passed through said channel detector, a plurality 0f conductors selectively activated singly or in combination by an invariable number of said relays when operated to indicate the digit or character designated by the number of frequencies in said plural frequency pulse, an alarm device, and means responsive to the operation of said invariable number of relays for disabling designations, comprising a pluralithy of channel detectors each adapted to pass a specific frequency therethrough of a plural frequency pulse designating a digit or character, a relay in each channel detector responsive to the frequency passed through said channel detector, a plurality of conductors selectively activated singly or in combination yby an invariable number of said relays when operated to indicate the digit or character designated by the number of frequencies in said'
  • a sender therefor which is adapted for the registration of wanted designations comprising a plurality of channel detectors each adapted to pass a specific fre,- quency therethrough of a plural frequency pulse designating a digit or character, a relay in each channel detector responsive to the frequency passed through said channel detector, a plurality of conductors selectively activated singly or in combination by an invariable number of said relays when operated to indicate the digit or character designated by the number of frequencies in said plural frequency pulse, and an alarm device operative in response to the operation of a different number of relays from said in variable number for preventing subsequent operation of any of said channel relays on any pulse transmitted Within a predetermined interval after the rst pulse.
  • a sender adapted for the registration of wanted designations, comprising a plurality of channel detectors each adapted to pass a specic frequency therethrough lof a plural frequency pulse designating a digit or character, a relay in each channel detector responsive to the frequency passed through said channel detector, a settable register, and circuits 20 completed between van invariable number of said relays when operated and said register for seti ting the register to indicate the digit or character designated by said plural frequency pulse.
  • a sender therefor which is adapted for the registration of a wanted designation, comprising a plurality of channel detectors each adapted to pass a specic frequency therethrough of a plural frequency pulse designating a digit or character, a relay in each channel detector responsive to the frequency passed through said channel detector, a plurality of conductors selectively activated singly orin combination by an invariable number of said relays when operated to .indicate the digit or character designated by the number of frequencies in said plural frequency pulse, and an alarm device responsive to the operation of less than said invariable number of relays for indicating a received pulse containing less than the required number of frequencies.

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  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Interface Circuits In Exchanges (AREA)
  • Telephonic Communication Services (AREA)
  • Monitoring And Testing Of Exchanges (AREA)
US375713A 1941-01-24 1941-01-24 Telephone system Expired - Lifetime US2317191A (en)

Priority Applications (5)

Application Number Priority Date Filing Date Title
US375713A US2317191A (en) 1941-01-24 1941-01-24 Telephone system
FR887178D FR887178A (fr) 1941-01-24 1941-12-11 Systèmes téléphoniques et analogues
DEST61351D DE745935C (de) 1941-01-24 1941-12-13 Schaltungsanordnung fuer Fernsprechanlagen mit Speicherbetrieb und mit tonfrequenter, in Codeform ausgefuehrter Stromstossgabe
GB2394/42A GB551431A (en) 1941-01-24 1942-02-24 Improvements in or relating to telephone systems
NL70302D NL70302C (xx) 1941-01-24 1947-04-24

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US375713A US2317191A (en) 1941-01-24 1941-01-24 Telephone system

Publications (1)

Publication Number Publication Date
US2317191A true US2317191A (en) 1943-04-20

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ID=23481995

Family Applications (1)

Application Number Title Priority Date Filing Date
US375713A Expired - Lifetime US2317191A (en) 1941-01-24 1941-01-24 Telephone system

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US (1) US2317191A (xx)
DE (1) DE745935C (xx)
FR (1) FR887178A (xx)
GB (1) GB551431A (xx)
NL (1) NL70302C (xx)

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2434898A (en) * 1943-01-13 1948-01-27 Bell Telephone Labor Inc Digit registering means responsive to selective frequencies
US2534822A (en) * 1944-11-17 1950-12-19 Ericsson Telefon Ab L M Connecting device for telephone exchanges using a register
US2549861A (en) * 1939-02-07 1951-04-24 Int Standard Electric Corp Teleprogramme on automatic telephone circuits
US2564378A (en) * 1946-05-06 1951-08-14 Punch Engineering Pty Ltd Carrier system signaling circuits
US2572740A (en) * 1948-05-10 1951-10-23 Bell Telephone Labor Inc Private branch exchange telephone system
US2620401A (en) * 1945-04-04 1952-12-02 Vigren Sten Daniel Automatic telephone system
US2651679A (en) * 1947-02-07 1953-09-08 Int Standard Electric Corp Electric signaling system
US2697749A (en) * 1951-06-20 1954-12-21 Bell Telephone Labor Inc Multifrequency telephone switching system
US2724183A (en) * 1945-12-27 1955-11-22 Calibron Products Inc Remotely controlled precision drive and calculating systems
US2732432A (en) * 1951-07-13 1956-01-24 hullegard
US2930852A (en) * 1954-04-08 1960-03-29 Post Office Alternating current signal receiving apparatus

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2201296A (en) * 1938-10-18 1940-05-21 Bell Telephone Labor Inc Telephone system

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2549861A (en) * 1939-02-07 1951-04-24 Int Standard Electric Corp Teleprogramme on automatic telephone circuits
US2434898A (en) * 1943-01-13 1948-01-27 Bell Telephone Labor Inc Digit registering means responsive to selective frequencies
US2534822A (en) * 1944-11-17 1950-12-19 Ericsson Telefon Ab L M Connecting device for telephone exchanges using a register
US2620401A (en) * 1945-04-04 1952-12-02 Vigren Sten Daniel Automatic telephone system
US2724183A (en) * 1945-12-27 1955-11-22 Calibron Products Inc Remotely controlled precision drive and calculating systems
US2564378A (en) * 1946-05-06 1951-08-14 Punch Engineering Pty Ltd Carrier system signaling circuits
US2651679A (en) * 1947-02-07 1953-09-08 Int Standard Electric Corp Electric signaling system
US2572740A (en) * 1948-05-10 1951-10-23 Bell Telephone Labor Inc Private branch exchange telephone system
US2697749A (en) * 1951-06-20 1954-12-21 Bell Telephone Labor Inc Multifrequency telephone switching system
US2732432A (en) * 1951-07-13 1956-01-24 hullegard
US2930852A (en) * 1954-04-08 1960-03-29 Post Office Alternating current signal receiving apparatus

Also Published As

Publication number Publication date
FR887178A (fr) 1943-11-05
DE745935C (de) 1944-12-19
GB551431A (en) 1943-02-22
NL70302C (xx) 1952-02-15

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