US2292977A - Electrical signaling system - Google Patents

Electrical signaling system Download PDF

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US2292977A
US2292977A US380226A US38022641A US2292977A US 2292977 A US2292977 A US 2292977A US 380226 A US380226 A US 380226A US 38022641 A US38022641 A US 38022641A US 2292977 A US2292977 A US 2292977A
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lines
line
marking
group
subscribers
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English (en)
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Taylor Reginald
Baker George Thomas
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Associated Telephone and Telegraph Co
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Associated Telephone and Telegraph Co
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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04M—TELEPHONIC COMMUNICATION
    • H04M15/00—Arrangements for metering, time-control or time indication ; Metering, charging or billing arrangements for voice wireline or wireless communications, e.g. VoIP
    • H04M15/08—Metering calls to called party, i.e. B-party charged for the communication

Definitions

  • the present invention concerns improvements in or relating to means for signaling the identity of lines or points over connections of which they form part and while particularly applicable to the identification of calling lines in telephone systems, it will, of course, be understood that it has other applications.
  • Identification of calling lines is required for a number of purposes, one of which is for the automatic recording of calls which are set up, and one application is described for instance in our co-pending application No. 329,608.
  • the system is of the type in which each line or point requiring identification over a connection of which it forms part is marked in accordance with a code, as described for instance in our co-pending application No. 321,783.
  • a code as described for instance in our co-pending application No. 321,783.
  • an individual lead was provided from each private wire to one or more bank contacts of a switch which applied the necessary marking to the line for identification purposes.
  • the invention consists of dividing the lines or pointsv of which the identity may be required into a number of different groupings in such a way that no line or point belongs to exactly the same set of groupings as another. For instance in a 10,000 line exchange the lines or points may be divided into different groupings according to those which have the same thousands digit, those which have the same hundreds digit, those which have the same tens digit and those which have the same units digit.
  • one of the groupings at least is provided with a common lead for each of the groups constituting the grouping, from which common lead connections extend to the individual lines or points of the group and to which common lead momentary connections are made characteristic of the group, such connections to the individual lines or points of the group including means for isolating the individual lines or points from each other during the establishment of the momentary connections by which the individual lines or points of the group are distinguished from each other.
  • a relay device is provided for one at least of said groupings for each of the groups constituting a grouping, which relay device is operated to make a momentary connection characteristic of the group to each line or point of the group.
  • the static devices may take the form of condensers or nonlinear resistance devices, such as being formed of a material consisting of a mixture of silicon carbide and carbon and/or tungsten or molybdenum which is agglomerated under pressure and subsequently baked.
  • This latter device has the advantage of having normally a high resistance and therefor serving to substantially insulate a line while when a high voltage is applied thereto the resistance falls sufficiently to allow signaling currents to flow to the line.
  • two such static devices are provided per line, one connected between the line and a common leadto which similar devices connected to other lines having the same thousands and the same tens digit are connected, while the other impedance device is connected to a common lead to which other devices associated with lines having the same hundreds and units digits are connected.
  • a relay device is provided for connecting to all common leads associated with lines having the same thousand digit marking potentials at particular instants of time in the cycle determined by a rotary switching device or its equivalent.
  • a similar relay device is provided to connect up to all the common leads associated with lines having the same hundreds digit marking potentials at particular instants of time in the cycle determined as before mentioned. There are therefore ten relay devices provided for each grouping.
  • relay devices in operating serve to isolate the common leads from other common leads to which potentials are applied corresponding to the various tens digits and units digits respectively.
  • By allocating five contacts of a uni-selector switch for each digit it is possible to so control the pulses applied to the whole of the 10,000 lines that to each line there are two impulses for each digit selected out of a possible five pulses to characterise the particular digit to be transmitted.
  • the receiving switch which operates in synchronism with the marking control switch is then able to select various relay combinations corresponding to the number of the line to be identified, provided of course that it operates in synchronism in the manner described in our prior application No. 321,783.
  • Thirty-five code signals will be received by the ably of the well-known five unit type in which outgoing relay set and pairs of regenerator pins every digit consists of five parts and by sending corresponding to the various marking pulses for special signals in one or more of these parts the each digit are displaced in an arc of thirty-five various digits are indicated; parts or units withconsecutive pins thereon, and in this manner the out a special signal are known as spacing pulse, subscribers number can be stored in code by and those with a special signal, marking pulses.
  • the special signal characteristic of marking signals on to the test conductors of the a marking pulse comprises a pulse which is transvarious subscribers on a 10,000 line exchange and mitted along the private lead to an outgoing refor this purpose reference should be had to the lay set at the originating exchange where the line marking equipment of Figs. 1 and 2 in which calling number is usually stored.
  • both marking and spacing pulses involve the transmission of synchronising pulses which are supplied independently of the talking train and over a common lead from the marking control equipment to the outgoing relay set.
  • a total of four groups of five pulses each will be transmitted to the outgoing relay set and if storage is required this may be effected on an impulse storage and regenerative device of the type described in United States Patent No. 2,188,451, and in the manner disclosed in our co-pending application, No. 329,608, in which the outgoing relay set described is adapted to operate with identification equipment of the type according to the present invention.
  • the four digit number is thereupon stored in the same five unit code as received, a set of five pins in sequence on the regenerator forming each digit, and two selected pins in each of these groups of five being displaced in accordance with the particular digit involved.
  • static connecting device is employed to cover any device which is normally an insulator or substantially so and is adapted to become conducting with appropriate changes applied thereto such as changes of voltage without necessitating the movement of any external member asso iated therewith.
  • the exchange is assumed to be of the rotary line switch type and it will be understood that the test wire of each subscriber is connected via static connecting devices such as SCD'I and SCD2 to two common leads extending from the line marking equipment, the connections for subscriber No. 1185 being showninthe drawings.
  • the devices SCDI of each subscriber having the same tens digit in each 100 line group are commoned together so-that the 1 00 devices such as SCDI are connected to ten common leads.
  • These common leads from each 100 line group having the same thousands digit are in turn commoned together so that for each of the different thousands digits in the exchange there willbe ten common leads (corresponding to the various tens digits 14)), which respectively extend to ten armatures of a thousands group switching relay such as yl MA, (relays IMA, ZMA bein provided for the various 1,000 line groups) Over operated armatures of reach of these re-- lays marking signals characteristic of the various thousands groups are communicated via the devices suchasSQDl to the subscribers test conductors.
  • relays ICA, ZCA are provided and to the ten armatures of each of these relays extend ten common leads from the subscribers in the groups having the relevant hundreds digit.
  • Alternating current code signals are employed in order that connection of the signal receiving device at, for instance, the outgoing relay set,
  • the test conductors may be made to the test conductor without interfering with the direct current guarding, holding and signaling potentials which may be present thereon.
  • the two connections from the line marking equipment toieach test lead are made via the connecting devices SCDI and SCDZ which may each comprise a condenser which would allow alternating current to pass therethrough and which would at the same time isolate the circuit against a flow of direct current to or from the P conductor.
  • the connecting devices SCDI and SCDZ which may each comprise a condenser which would allow alternating current to pass therethrough and which would at the same time isolate the circuit against a flow of direct current to or from the P conductor.
  • use might be made of a multi-electrode neon tube which would have one central common electrode surrounded by say ten individual electrodes all of which would break down when a marking signal was applied to provide a common connection to ten P conductors.
  • a cheap, efiicient, and generally preferred form of connecting device which is assumed to be utilised in Fig. 1 consists of a unit of non-linear resistance material which is substantially an insulator when the voltage across it is the normal exchange battery potential of fifty volts, but the resistance of which decreases considerably with an applied signal voltage having a value greater than fifty volts.
  • a preferred example of this material is a mixture of silicon carbide with carbon and/or tungsten or molybdenum which is agglomerated under pressure and subsequently baked.
  • the material is conveniently made up in the form of discs about the size of a shilling, and the flat surfaces sufliciently to give a satisfactory contact.
  • connecting devices SCDI and SCDZ comprise, non-linear resistance discs
  • the various common leads to which the discs are connected asshown in Figs. 1 and 2 are normally connected to the negative side of the exchange battery in order to prevent possible back feed trouble in the case where for example the majority of the private conductors are earthed and the minority are not earthed, in which case it might be possible to hold operated the cut-off relays connected to the latter P conductors were it not for the negative battery connected to the common lead which provides an effective short circuit for said relays; Owing to the non-linear characteristic of the discs, the current drain on busy lines, the test conductors of which are earthed, will be almost negligible, while the current drain on free lines will be zero.
  • Signaling the identification of calling lines is performed by injecting an AC signaling voltage into the battery connected common.
  • non-linear resistance units instead of condensers as static connecting means gives an advantage as regards the amount of operating power which can be delivered to line.
  • non-linear resistance units only those units in circuit between the common signaling point and the P conductors will be caused to lower their resistances when the A. C. signaling voltage is applied while the other unit of the pair in each case maintains its normal high resistance and so do not offer any serious leakage shunt path as is the case with condensers, the impedance of which does not alter with variation in voltage.
  • the use of non-linear resistance units therefore enables a given power output to be delivered to line with a minimum wastage of power in shunt paths.
  • the outgoing relay set at the originating exchange is adapted on being taken into use to set in operation identification equipment which thereupon communicates details of the calling number thereto. This number is stored until information as to the identification of the calling party is required by the exchange at which the toll recording equipment is situated.
  • relay IGR The operation of relay IGR, is dependent on the open condition of impulse springs IPB which are continuously operated in synchronism with springs IPA at a rate of about ten impulses per second, and as soon as these springs open after having been closed, relay IGR operates and at armature z'grl connects springs IPB up to magnet MSM of the switch MS while at armature i913 earth is extended to springs IPA which connect up with the pulse lead PU extending to the outgoing junction relay set, over which lead the synchronizing pulses are extended.
  • Contacts 2I6 of the MS switch bank MS] are allocated for this purpose, these contacts being divided up into three groups of five contacts each, and being strapped to relay ECR in accordance with the particular marking signals to be transmitted for the code 405. For this code it will be remembered that pulses Nos. I and 5, 9 and It], I2 and I3, will have to be marking pulses so that corresponding contacts 2, 6, I8, ll, I3 and M on bank MS! will be strapped to relay ECR.
  • wiper MSI will extend an earth to operate relay ECR which thereupon at armature ecrl (Fig. 4) connects a commercial 50 cycle frequency alternating current source via transformer TRA on to the exchange code common lead EC extending to the outgoing relay set; lead EC is common to the various outgoing relay sets in the same way as the already mentioned common leads ST-Z.
  • Marking and spacing signals are transmitted in this manner to set up the code indicative of the prefix portion of the calling number on the outgoing relay set regenerator.
  • the marking switch wipers on reaching position I! commence to signal the numerical portion H85 of the calling subscribers number.
  • the spacing signals simply comprise pulses delivered directly to the outgoing relay set regenerator over the PU lead, but now the marking pulses comprise pulses delivered simultaneously over the PU lead and via the line marking equipment of Figs. 1 and, 2 to the private leads of the various subscribers on the exchange, from whence they may extend via connections already set up to outgoing relay sets.
  • Marking signals characteristic of these four digits are distributed from the banks MSl-MSB (Figs. 3 and 4) of switch MS, which banks are wired up as shown to four groups of leads extending to the linemarking equipment (Figs. 1 and 2) the groups TH, HU, TE and UN, serving the thousands, hundreds, tens and units digits respectively.
  • 1185 in breaking down will allow the marking signal to extend to the out.- going relay set where it operates the signal respending relay to cause the regenerator marking magnet to operate and by displacing a pin to store the signal on the regenerator. This will apply to all the above-mentioned subscribers lines from which calls have been set up to outgoing relay sets while in the case of other lines having the thousands digit 1 and from which such calls have not been setup the signals will not be made use of.
  • the leads 2, 3, 4 of the thousands group TH are also earthed over wipers and banks M85, M83 and MS! respectively, and the respective group switching relays ZMA, 3MA and 4MA are operated to extend a marking signal on to the test conductors of all subscribers on the exchange having the thousands digit 2, 3 or 4' as. all. these digits have in their code designations. the same initial pulse.
  • wiper and bank M38 For the purpose of extending marking signals to line indicative of the tens and units digits of the subscribers numbers, wiper and bank M38 is utilized which connects up with five coding leads V, W, X, Y, Z'in turn in the tens'and units groups TE and UN so as differentiall-y'to operate the tens and units coding relays VT--,ZT, VU-- ZU and so effect the markings;
  • a non-linear resistance disc NLRI of the same type as is used for connecting devices SCDI and SCDZ is connected in series with the primary winding of the transformer TRB and the 50 cycle source is connected up as shown.
  • the output in the secondary winding of this transformer will contain a. large third harmonic component, i. e. 150 cycles, and the combined 50 plus 150 cycle output obtained in the secondary winding is thereupon supplied over a common lead to the various out-1 going relay sets.
  • the relative strengths of the 50 cycle and 150 cycle frequencies in the output circuit are adjustto start up the identification in response to a signal from the toll recording exchange, the marking signals received over either the P conductor and the PU lead or the EC lead and the PU lead from the identification equipment will be converted at the outgoing relay set into 150 plus 50 cycle signals before being extended out on to the junction line to the toll recording exchange, while spacing signals which will be received from the identification equipment over lead PU only will be transmitted to line as 50 cycle signals.
  • a. 50 cycle supply is made available to the various outgoing relay sets from the marking control relay set.
  • the invention is not limited to the precise line marking arrangement described, and the equipment could be made almost completely static in operation by using say four static connecting devices per line in the case of a 10,000 line exchange.
  • each of these lines will be dealt with as a separate line, and will be provided with two static connecting devices.
  • the centre tapped sides of these devices will be Wired out to the various P conductor of the P. B. X group, while the other sides thereof may be wired out to the same common points, so as to receive the same markings. Further consideration of this feature is given in British application No. 9886/40.
  • the invention provides an extremely eificient method of line or point identification owing to the use of so few moving parts, while at the same time the cost per line is small.
  • a plurality of subscriber lines arbitrarily divided into a plurality of primary groups and a plurality of secondary groups so that each line belongs to a particular primary group and also to a particular secondary group and so that none of th lines belonging to the same primary group belong to the same secondary group and none of the lines belOnging to the same secondary group belong to the same primary group, a different signal input for each of said groups, means permanently connecting each of said lines to the signal input for the primary group to which that line belongs, means also permanently connecting each of said lines to the signal input for the secondary group to which that line belongs, and mean associated with each input for impressing upon all lines connected thereto a signal characteristic of the group corresponding to that input, whereby each of said lines has impressed upon it signals characteristic of both groups to which it belongs.
  • a plurality of subscribers lines arbitrarily divided into a plurality of primary groups and a plurality of secondary groups so that each line belongs to a particular primary group and also to a particular secondary group and so that none of the lines belonging to the same primary group belong to the same secondary group and none of the lines belonging to the same secondary group belong to the same primary group, a different signal input for each of said primary groups, means permanently connecting each of said lines to the signal input for the primary group to which that line belongs, means associated with each signal input for impressing upon all lines connected thereto a signal characteristic of the primary group corresponding to that input, and means for also impressing up each of said lines a signal characteristic of the secondary group to which that line belongs.
  • each of said subscribers lines has different values of direct current potential impressed upon it at difierent times
  • the means connecting each of said lines to a signal input includes a device for preventing the directicurrent potential present on that line from manifesting itself at said signal input.
  • a plurality of subscribers lines arbitrarily divided into a plurality of primary groups and a plurality of secondary groups so that each line belongs to a particular primary group and also to aparticular secondary group and so that none of the lines belonging to the same primary group belong to the same secondary group and none ofthe lines belonging to .the sam secondary group belong to the same primary group, a different signal input for each of said primary groups, a permanent connection extending from each of said lines to the signal input for the primary group to which that line belongs, means associated with each signal input for impressing upon all of said lines connected thereto a signal characteristic of the primary group corresponding to that input, means for also impressing upon each of said lines a signal characteristic of the secondary group to which that line belongs, and means in each said permanent connection between a signal input and a subscribers line for preventing the signal characteristic of the secondary group to which that line belongs, when impressed upon said line, from passing over said connection to said signal input, whereby no line can receive over its connection to a particular signal input the signal characteristic of
  • a system as claimed in claim 5, wherein said last means comprises a non-linear resistance having a high resistance when a low voltage is impressed upon it and a lower resistance when a higher voltage is impressed upon it.
  • a plurality of subscribers lines arbitrarily divided into a plurality of primary groups and a plurality of secondary groups so that each line, belongs to a particular primary group and also to a particular secondary group and so that none of the lines belonging to the same primary group belong to the same secondary group and none of the lines belonging to the same secondary group belong to the same primary group
  • a static resistor associated with each of said subscribers lines means permanently connecting each of said lines via its associated resistor to the signal input for the primary group to which that line belongs, said resistors having a non-linear resistance characteristic and, in the absence of a signal in the sign-a1 input to which they are connected, being of such resistance as to substantially insulate irom one another the subscribers lines connected to that signal input
  • a plurality of subscribers lines arbitrarily divided into a plurality of primary groups and a plurality of secondary groups so that each line belongs to a particular primary group and also to a particular secondary group and so that none of the lines belonging to the same primary group belong to the same secondary group and none of the lines belonging to the same secondary group belong to the same primary group, two static resistors associated with each of said subscribers lines, a different signal input for each of said groups, means permanently connecting each of said lines via one of its associated resistors to the signal input for the primary groups to which that line belongs, means permanently connecting each of said lines via the other of its associated resistors to the signal input for the secondary group to which that line belongs, said resistors having a nonlinear resistance characteristic and, in the absence of a signal in the signal input to which they are connected, being of such resistance as to substantially insulate from one another the subscribers lines connected to that signal input, means for generating in each signal input a signal characteristic of the group corresponding to that input, said signal effective to render the static resist
  • a plurality of subscribers lines arbitrarily divided into a plurality of primary groups and a plurality of secondary groups so that each line belongs to a particular primary group and also to a particular secondary group and so that none of the lines belonging to the same primary group belong to the same secondary group and none of the lines belonging to the same secondary group belong to the same primary group, means associated with each primary group effective normally to connect in multiple all subscribers lines belonging to that group whether those lines individually are idle or engaged in calls, means for at times impressing upon the lines of each primary group over the multiple connection to those lines a signal characteristic of that primary group, means for at other times impressing upon each of said lines a sign-a1 characteristic of the secondary group to which that line belongs, and means operated to interrupt said multiple connections at said other times to prevent any line from receiving over said multiple connection the signal impressed at said other times upon any other line belonging to the same primary group as that line.
  • said network including a permanent connection from each of said lines to every other one of said lines, and means in the connection between each pair of lines for preventing the direct current potential present upon one line of said pair from manifesting itself upon the other line of said pair.
  • a static resistor in the connection between each pair of lines, said resistor having an inverse non-linear resistance characteristic and acting substantially as an insulator in the presence of said potential difference sometimes existing between said pair of lines, and means for at times impressing another potential upon said resistor to cause it to become conductive.
  • a plurality of subscribers lines terminate in the same exchange, and wherein each of said lines has different values of direct current potential impressed upon it at different times, whereby a difference 14.
  • a plurality of subscribers lines each characterized in one Way when it is idle and in a different way when it is engaged in a call, means normally connecting said lines in multiple regardless of whether said lines individually are idle or engaged in calls, and means in said multiple connection for preventing the way in which any line is characterized from being manifest, over said multiple connection, at any other line.
  • a static device for each of said lines for each of said lines, a junction point common to all of said lines, means normally connecting each of said lines via its static device to said common point regardless of whether that line is idle or engaged in a call, each of said devices effective to prevent the way in which its associated line is characterized from being manifest at said common point.
  • a static device for each of said lines for each of said lines, a junction point common to all of said lines, means normally connecting each of said lines via its static device to said common point regardless of Whether that line is idle or engaged in a call, each of said devices effective to prevent the way in which its associated line is characterized from being manifest at said common point, means for impressing a signal upon said common point, each of said devices effective to conduct said signal to its associated subscribers line.
  • a plurality of groups of subscribers lines a common lead for each said group, means permanently connecting each of said lines to the common lead for the group to which that line belongs, means effective to divide said common leads into groups in different ways at different times so that common leads belonging to the same group at one time will belong to difierent groups at another time, and means for impressing upon said common leads at each of said times a signal characteristic of the group to which that lead belongs at that time.

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  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Devices For Supply Of Signal Current (AREA)
  • Interface Circuits In Exchanges (AREA)
  • Monitoring And Testing Of Exchanges (AREA)
US380226A 1940-03-23 1941-02-24 Electrical signaling system Expired - Lifetime US2292977A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB5349/40A GB539823A (en) 1940-03-23 1940-03-23 Improvements in electrical signalling systems

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US2292977A true US2292977A (en) 1942-08-11

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US380226A Expired - Lifetime US2292977A (en) 1940-03-23 1941-02-24 Electrical signaling system

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US (1) US2292977A (en(2012))
BE (1) BE468235A (en(2012))
DE (1) DE826019C (en(2012))
FR (1) FR933091A (en(2012))
GB (1) GB539823A (en(2012))
NL (1) NL63940C (en(2012))

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2547804A (en) * 1946-07-25 1951-04-03 Automatic Telephone & Elect Telephone line identification system
US2550181A (en) * 1946-05-25 1951-04-24 Automatic Telephone & Elect Line identification system
US2550208A (en) * 1945-03-23 1951-04-24 Automatic Elect Lab Circuit for the transmission of identification and metering signals of calling lines
US2591909A (en) * 1945-06-13 1952-04-08 Automatic Elect Lab Multiple office voice-frequency line identification system
US2598097A (en) * 1945-06-13 1952-05-27 Automatic Elect Lab Assembling and connecting nonlinear resistance elements
US2600502A (en) * 1948-04-24 1952-06-17 Bell Telephone Labor Inc Calling line and private branch exchange line identifier
US2884489A (en) * 1950-06-02 1959-04-28 Int Standard Electric Corp Electrical identification or selection equipment

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2550208A (en) * 1945-03-23 1951-04-24 Automatic Elect Lab Circuit for the transmission of identification and metering signals of calling lines
US2591909A (en) * 1945-06-13 1952-04-08 Automatic Elect Lab Multiple office voice-frequency line identification system
US2598097A (en) * 1945-06-13 1952-05-27 Automatic Elect Lab Assembling and connecting nonlinear resistance elements
US2550181A (en) * 1946-05-25 1951-04-24 Automatic Telephone & Elect Line identification system
US2547804A (en) * 1946-07-25 1951-04-03 Automatic Telephone & Elect Telephone line identification system
US2600502A (en) * 1948-04-24 1952-06-17 Bell Telephone Labor Inc Calling line and private branch exchange line identifier
US2884489A (en) * 1950-06-02 1959-04-28 Int Standard Electric Corp Electrical identification or selection equipment

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Publication number Publication date
BE468235A (en(2012))
GB539823A (en) 1941-09-25
NL63940C (en(2012))
DE826019C (de) 1951-12-27
FR933091A (fr) 1948-04-09

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