US2440277A - Calling line identification system - Google Patents

Calling line identification system Download PDF

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Publication number
US2440277A
US2440277A US486273A US48627343A US2440277A US 2440277 A US2440277 A US 2440277A US 486273 A US486273 A US 486273A US 48627343 A US48627343 A US 48627343A US 2440277 A US2440277 A US 2440277A
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Prior art keywords
relay
selector
group
line
circuit
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US486273A
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Kruithof Jacob
Kozma Ladislas
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International Standard Electric Corp
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International Standard Electric Corp
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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
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
    • C08L1/00—Compositions of cellulose, modified cellulose or cellulose derivatives

Definitions

  • This invention relates to new and useful improvements in arrangements for identifying calling subscribers lines.
  • Identification of this kind may be used to signal the identity of a calling subscriber to an operator, who is reached via an automatic switching train for certain classes of calls, which have to be handled by this operator, so that the operator has to make out a ticket containing all information required for calculating the cost of the call.
  • Certain identification schemes of this kind which have found practical application, have as their common feature that use is made of an alternating currentpotential applied to one wire of the subscribers line equipment at the exchange whenever it is desired to identify the calling line.
  • Switches are provided for this purpose, either of the line finder or the final selector type, which select the particular line in a given group.
  • this common point is provided at the subscribers line circuit by connecting each or lines through a suitable impedance, individual to the line, to a common starting circuit which is associated with an identification control equipment (see, e. g. application of L. A. Cabes, Serial Number 473,271, filed Jan. 22, 1943, and the Netherlands Patent No. 58,889, dated Feb. 15, 1947.).
  • This common point is used to select the final selector switch serving the group of 100 or 200 lines comprising the calling line.
  • the subscribers lines are so commoned that the common point will also indicate the level on the final selector switch on -which the calling line is to be found.
  • This system -permi-ts connecting the subscribers lines in any convenient manner to the line finder or preselector or similar non-numerical switch, because the common points may be in the final selector arcs, which are wired in numerical order to the subscribers lines.
  • the identification control equipment must have access to all final selector groups in the exchange, and it is therefore customary to provide one or more switches which give access to one or two final selectors in each group of, say, or 200 lines.
  • a feature of the present invention is that for identifying subscriber lines use is made of one or more stages of group selectors and of final selectors provided for the completion of regular connections and that the final selector brushes are directed to the line to be identified, access being provided from the identification equipment through the engaged group and final selectors to the wires to which marker potential is connected in the subscribers line circuits.
  • Another feature of the invention is that the final selector switch engaged for identification hunts for the set of subscribers line terminals marked by the presence of marking potential and signals to the identification control equipment the location of this set of terminals with respect to the home position of the switch.
  • the subscribers lines are connected in numerical order in the line finder arcs or in groups of pre-selectors
  • the identification is not limited by the number of the switches specially arranged or provided for this purpose as in one of the two methods described above, but access is given from the identification control circuit to all final selectors in each group of subscribers lines. In order to be able to do this, these finals are reached through regular penultimate selectors and the identification control circuit has associated with it a group selector -or finder by means of which it is possible to reach the regular local group selector equipment of the exchange. For example, it may be possible to provide a finder of Which the contact terminals are multiplied in parallel with the local level of the first group selectors. Alternatively, it is possible to associate directly with the identification control circuit a second group selector, the contact terminals of which are multiplied with the regular second group selectors.
  • means are provided for making a number of selections in one or two group selector stages to reach a final selector having access to the particular group of lines of which one has to be identified.
  • This selection can be made under the control of the identification control circuit because the common point on which the identification tone is placed identifies the particular group of, say, 100 lines in which the calling line has to be found. It is necessary to determine the individual line connected to the group of final selectors selected, by letting the final selector hunt over its terminals until it finds the one having the identification tone placed on the subscribers line connection. Means should,
  • the final selector and group selectors are so arranged that they can transmit this tone to the identification contnol circuit, and that the final selector, through the group selector stages, can be moved under the control of the identification control circuit until it reaches the line to be identified.
  • the subscribers line indicated by the presence of an alternating current marker potential
  • a line finder associated with the identification contnol circuit, and to certain bank terminals of which the common points of all subscribers line groups in the exchange are connected, to hunt for the common point in its bank on which the marker potential is present.
  • the position of this finder is indicated by means of characteristic potentials of current applied to other terminals of its bank from certain sources of current. These sources diifer in at least one of their electrical characteristics to represent the different digits of the subscribers numbers corresponding to the common points, there being as many rows of terminals in the finder as there are digits to be identified to determine the common point.
  • a further feature is that the characteristic potentials, identifying the group of lines from which one is to be identified, are used for the purpose of controlling one or more selections in group selector stages in order to set up from the identification equipment a connection to a final selector in the group to which this subscribers line is connected.
  • Such characteristic potentials can further be used in systems in which group selectors are set by comparing a signaling current ,sent from the selector with a reference current denoting the group to be selected. In such systems the characteristic potentials are used as reference currents for the purpose of setting one or more stages of group selectors to extend a connection from the identification control equipment to a final selector in the group to which this subscribers line is connected.
  • a further feature is that these characteristic potentials are used to govern the sending of numerical impulses denoting one or more digits of the calling subscriber's number from the identification control equipment to the equipment on which the calling subscribers identity should be displayed or recorded.
  • This invention is not limited to the use of the type of group and final selectors shown in this embodiment, but is equally applicable to other switching systems, such as those using forward or directive impulses or revertive impulses sent from group and final selectors to a register circuit.
  • the group and final selectors are so arranged as to be accessible from the identification control circuits.
  • the identification control circuit is connected to one brush of the final selector and causes it to hunt for the identification tone placed on the subscribers line.
  • the position of the final selector in which this tone is found can be determined from the number of forward or revertive impulses sent, after moving the brush carriage from its normal position.
  • Another possibility is to determine the number I lOf steps needed to restore the brush carriage to its normal position from the terminal on which the identification tone was found.
  • the tens group of the calling line can be determined. This depends on the design of the final selectors. With final selectors having two distinct motions, it is necessary to control from the identification control circuit the setting to one particular group of lines during the act of identification. For this purpose, the identity of this group is indicated by the fact that the subscribers lines are commoned in groups of, say, 10 or 20 lines, corresponding to the groups of lines connected to the final selector banks. With final selectors having a single motion for reaching all subscribers lines connected to their banks, it is possible to connect, say, or 200 subscribers lines to one common point, depending on the capacity of the final selector and to use the final selector for signaling the identity of the tens group to the identification control circuit.
  • characteristic potentials are connected in two different. rows or groups ofterminals in the final selector arcs, one.
  • the tens and units digits are directly determined at the identi'fication control circuit when the final selectorarrives on the line to be identified, without any counting action taking place whilst the final selector is moving.
  • the manner which the line is identified depends on the manner in which thefi-nal selector works, as described. in the application U; S. 'Ser. No. 472,624 referred to, but in each. case the same means which are used for setting the final selector under the control of. the register when making a selection to 2. called subscriber line, can. be used for identification. purposes to. signal thepositi'on of the final: selector brush carriage' to the identification control circuit.
  • Fig. 1 is a junction diagram representing the relation between the difierent circuits
  • Fig. 2 shows the universal selector circuit, which is employed as group and as final selector
  • Fig, 3 shows the path; of the alternating cur.- rents used for the purpose of identification; and- Figs. 4 and 5 show the. identification controlcircuit.
  • a telephone exchange of a multi-ofiice area as shown. in Fig, 1, a subscriber's local connection isbui-ltlup over linefinders group. and final selectors in the known way;
  • the connections which require. identification (automatic toll, rapid toll service. (GER), multi-taxed rural connections, etc.) pass. via first. group selectors'towards a tollmain exchange.
  • identification of the calling subscriber may be initiated over the junction from the main ex change at any appropriate moment.
  • the local exchange end of the junction is equipped. with the necessary material required: to start the idea tification process.
  • a part of this equipment, which is either provided per junction or may be separated in common control circuits, is shown in Fig. 4.
  • the junction circuit engages one free i'd'en tifi'cation control circuit (Figs. 4. and 51) out of the group provided, and at the same time tone irequency current is connected by the junction ctr-- cult to the 0 wire of the subscribers line circuit over first group selector and first and second line findercircuits, as shown in Fig. 3-.
  • Theidentification control circuit engaged starts to hunt with its ICF finder for the identification calling tone, and picks it up over a common point representing one group of first line finder circuits, or in other words, 100 subscribers.
  • Thecircuit of this com-- mon point is shown in the lower left-hand part of Fig. 4.
  • the position of ICF now indicates to the identification control circuit the group of final selectors which has access to the 100' subscriber lines, including the line of the callingsubscriber.
  • the identification control circuit engages one free final selector over second and third group selectors, and causes the rotation of the final selector until the calling tone on wire c of the subscribers. line circuit is found.
  • the identity of the subscriber is now determined by the position of ICF, and that of the final. ICF gives the. thousands and hundreds digits of the, sub scribers number, whereas the tens and units 6 digits are fixed by thepositlon of the final selector.
  • the identification control circuit proceeds now to send out these digits towards the junction circuit, and from there they will be retransmitted to that circuit of the main exchange, which called for the subscribersnumber.
  • the scheme makes use of two tones of different frequencies, i. e. T1 and T2 for calling and sending purposes. These frequencies, which are both present on the path at a certain moment, are separated at the ends of this path by tuned filters F1 and F2; 111- Fig; 3 the arrows crossed twice indicate the path of the calling tone T1, which is: picked up first by IGZF and then by a final selector. The arrows crossed once trace the circuit of theimpulse sending for which the tone T2 is: used. Filter F1, a filter which passes the tone Ti and F2, is the toneTa.
  • the idle. condition of' this circuit is characterized by the presence of' a free test potential on are a of I'M.
  • This test potential is provided via a resistance of 500' ohms and is controlled on the home contact of the access finder ICF.
  • Relay Cdr inserted into the low resistance circuit is a marginalrelay and operates only if one such relay is. connected to the test potential.
  • Relay Cdr in turn. operates relay Uhr. Relay Uhr then operates relay Ilr, which disconnects. relay Tooth over its left inner armature; the relays Cir and C117", however, remain operated as long as the test potential is available from. the control circuit.
  • the calling tone T1 is then connected via the filter Fl to. the terminal marked by B.
  • the filter F2 is tuned to the. sending frequency T2 and prevents the calling. tone from reaching the tone detector circuit prepared; for the reception of the over a resistance of I5,000 ohms and. is induced. over the step-up transformer T to terminal D,
  • the tone is tested by the cold cathode tube GT5 and the finder is stopped by the operation of relay Ttr.
  • the principal characteristics of such tubes have been described in the patent specifications referred to above.
  • the control anode b is connected over the secondary winding of transformer ITl to a Variable resistance of 100,000 ohms, branched to the 130 volt positive battery.
  • the potential of the control anode with respect to the cathode c is, under idle conditions, something like 65 volts, thus below the breakdown voltage of 70 volts.
  • the primary winding of transformer ITl is connected to brush a of ICE, and whilst the access finder is rotating, the terminals D are checked for the presence of calling tone.
  • Relay Ttr energizes relay Kcr and the circuit now ensures that the finder is stopped by the tone and not by some potential change on one of the 0 wires, over which usually many other operations are performed.
  • Relay Ctr is energized as soon as the armature of Isr has made front.
  • Relay Ctrl is a slow releasing relay, and now that Kcr operates, it starts to release. During its releasing time the tube CTI is extinguished at least once, and it has to light up again if the tone is still on the tested terminal.
  • Relay Kcr energizes the magnet of switch IS, which is a dial impulse sender switch. The impulses are directed via front of relay Kcr to relay Ipr, which follows these impulses.
  • Relay Ipr opens the circuit of relay Ttr, which releases and at the same time the tube CTI extinguishes. As soon as relay Ipr releases, Ttr has to operate again because the tube is ionized. The brushes of finder ICF are during the release of relay Ttr disconnected by relay Ipr and do not move. Relay Kcr remains operated, being energized alternatively by relay Ttr or Ipr.
  • a double D. 0. test is carried out in order to ensure that only one finder ICF comes to rest in a certain position.
  • the test potential is furnished by the resistance of 500 ohms connected to terminal b on the arc of ICE.
  • the high resistance winding of relay Dcr is connected by relay Kcr to this test potential, and the relay operates.
  • Relay Dcr introduces its low resistance winding and renders the terminal busy in the known way, against other test relays.
  • Relay Dar is the marginal relay, the operation of which indicates successful testing.
  • relay Dcr fails to operate, whereby magnet ICF is energized and the finder leaves this position. If the next position is free, relay Dcr operates and switch ICF stops. If there is no tone, relay Ttr does not operate any more, and relay Kcr release-s. The magnet of ICF is now energized again via back of relay Ttr and hunting continues.
  • Relay Dcr energizes relay Olcr in the following circuit: Ground, Kcr front, Ctrl back, For back, Der front, winding of relay Okr, battery.
  • the first result of the operation of relay Okr is that full ground is connected to brush a of ICE, whereby the testing of other control circuits on the same terminal is prevented.
  • Relay Okr opens the test potential of 500 ohms connected to are a of switch IM, with the result that relays Ctr, Cdr
  • the transformer ITI receives now no tone, so that on the next operation of relay 1111' the tube Ctl extinguishes.
  • Relay Ttr does not operate thereafter and relay Kcr releases.
  • the impulse sender switch stops.
  • relays Dcr and Dzr release the guarding of the position not being necessary any more.
  • Relay Okr locks itself via the back of relay Rlr and will only release at the end of the identification.
  • Relay Olcr energizes the relays Ggr and Ghr; the operating ground is thereby controlled via the normal position of the different step-bystep switches of the circuit. Once operated relay Ggr remains energized as long as relay Okr is operated.
  • Rela'y To-r then closes the following circuit for relay Dtr: Ground, winding of relay Dtr, front of relay Tor, 0 wire, back of relay Ar, resistance of 600 ohms, battery. 7
  • Relay Dtr operates relay Sar, which, whilst energizing magnet SM, locks itself to the interrupter of this switch.
  • relay Ar ground, winding of relay Tr, back of relay Gbr, Ssr front, Tor front, b wire, Br back, Ar back, winding of relay Ar, battery.
  • relay Tr in this circuit is of no importance.
  • Relay Ar operates and locks to the 01 wire to which ground is connected via a front of relay Okr.
  • relay Ar operates, the battery of 600 ohms is disconnected and relay Dtr releases. If magnet SM is already fully energized, relay Sar releases now, and the brushes of SM make one step. Leaving position normal, SM removes the operating ground of relay Tor, which releases before Gbr could operate.
  • Relay Ssr remains operated in position 1 of SM and the selector switch of the second group selector starts to rotate as soon as relay Vrr, which is kept operated by relay Sar, releases.
  • the circuit of the power magnet P is as follows: ground, back contact of relay Vtr, back contact of relay Tor, front contact of relay Ssr, back contact of relay Vrr, a wire, back contact of relay Brlc, front contact of relay Ar, magnet P, battery.
  • the selection is determined by the thousands digit of the calling subscriber, and this is known from the position of ICF.
  • the selec tion process itself has been described in detail in the patent specification already mentioned above.
  • the principle of the selection is the comparison of two A. 0. sources of different ;9 phases.
  • One A. C which is called fsignaling current is available over the d brush of the second group selector and is furnished by the third group selector and this changes its phase for each group of thir group selectors available.
  • the second alternating current, called reference current depends on the position of ICE, These two currents are compared by the receiving equipment (Fig.
  • the circuit of the signaling current is: ground, front con-tact of relay Ggr,
  • the circuit of the reference current is: ground, front contact of relay Gg'r, primary winding of transformer HCZ, brush b and terminal I of SM, brush 0 of ICF, .source of alternating current to ground.
  • the receiving equipment has the necessary means to compare the above two currents and at the moment it detects that the currents are in phase, the tube C'I'Z, becomes ionized and relay Vtr operates.
  • Relay Vtr opens the circuit of the power magnet and the selector stops on the terminals of an outlet in the wanted group.
  • the tube 'CT3 is a voltage stabilizer furnishing '75 volts steady potential for the tube GT2.
  • Relay Vtr energizes relay Fir in the circuit: ground, front contact of relay Vtr, back contact of relay Dsr, back contact of relay Lsr, back contact of relay Fhr, winding'of relay Fir, battery.
  • mlay Etr prepares a locking circuit for .itself over the winding of relay Fhr and opens the circuit of relay Crh. This latter relay removes the .130 volts positive battery from the anode of tube CT-2.
  • Relay Vt'r is caused to release, whereby the short circuiting ground on relay Fhr is removed and this relay operates in series with relay Fir, via the back contact of relay Vrr and the front contact of relay Srr.
  • Relay Ehr closes back the operating circuit of relay Chr,
  • the alternating current test is repeated in the above manner twice, in order to ascertain that the selector switch is standing, after stopping on the terminals of the outlet engaged.
  • Relay Tor closes the following direct current test circuit: ground, winding of 2000 ohms of relay Tr, back contact of relay Gb-r, front contact of relay Ssr, front contact of relay Tor, wire 1)., back contact of relay Br, front contact of relay Ar, winding I of relay Br, brush 0 of second group selector, back contact of relay Ar, resistance of 600w, to battery in the third group selector.
  • relay Tr In this circuit only relay Tr can operate, Whereas relay Br, due to the high resistance of relay Tr, does not operate.
  • the front contact 'of relay Tr connects relay .Dtr and its low resistance winding in parallel to its high resistance winding, thereby rendering the test potential of 600w busy against other calls, and at the same time increasing the current .so that Br can operate.
  • Relay Dir is a marginal relay, and can only operate if it is connected alone to the test potential.
  • Relay Dtr energizes relay Sar in an obvious circuit.
  • Relay Ear energizes the step-by-step switch 'SM and operates at the same time also relay Vrr, I
  • Relay Sar once operated locks itself to the interrupter contact of SM in order to be sure that SM is .fully energized.
  • the seizure relay Ar in the third group selector is energized the 600w test potential is disconnected.
  • Relay Dir releases when the test potential is removed and, if 'SM at this moment is already ii ul'ly energized, relay Sar releases.
  • the brushes of :SM now .make one step and arrive at termi- Relay S ar releases relay VT? and this relay in turn allows the re-operation of relay Chr and now the receiving equipment is ready for the next selection.
  • relay Br in the first group selector starts to operate as soon as the high resistance winding of relay Tr is shunted by relay Dir.
  • Relay Br is a slightly slow operating relay due to its short-circuited second winding; this in order to cover the releasing time of the test relays in case of simultaneous test by two or several circuits.
  • relay Br When relay Br operates it removes first of all the short circuit on its second winding, thereby providing a locking circuit to the battery over 60th] resistance. addition, it short-circuits its operating winding via a front contact, which closes later than the back contact removing the short-circuit mentioned above.
  • relay Tor When relay Tor, after successful alternating current testing, has operated, it disconnects the primary winding of transformer H0! and replaces it by a second low resistance winding of relay Btr. As soon as relay Br energizes, it connects this second winding of relay Dir on its left outer change-over contact to the 0 Wire in parallel with the other winding of relay Dtr. The inner left change-over con-tact connects through he 2) wire towards the third group soiector. The test potential at this moment is guarded by the second Winding of relay Dtr.
  • the low resistance circle-t of relays Tr and Dtr now energ-ize relay Ar oi the third group selector in the following circuit: Ground, front contact of relay Sar, winding 1 of relay Dir, winding of relay Tr, contact of relay Ghr, front contact of relay SS7, fron t contact of relay Tor, b wire, front cohtact of relay Br, b of the second group selector, back contact of relay B1", back contact of relay winding of relay A1, battery in the second group selector.
  • Relay Ar operates in this circuit and looks itself over brush d to the ground available via the front contact of relay Br in the second group selector.
  • the alternating current which was in any case already short-circuited by the above mentioned ground, is now disconnected at the back contact of relay Ar in the second group selector.
  • relay Ar disconnects also the D. C. test potential of 600w, which causes the release of relay Dtr in the way already described.
  • the alternating current test is repeated in order to be sure that the group selector, after stopping, makes contact with terminal d of the group selector of the next stage. Should it happen that the selector stops too far, so that the desired contact is passed, the circuit operation changes in the following respect:
  • relay Vtr On the first operation of relay Vtr, relays Fir and Fhr operate in the manner described. Relay Chr connects back the positive battery to the tube GT2, but now relay Vtr fails to operate and owing to this relay Kir energizes in the circuit: ground. back contact of relay Vtr, back contact of relay Tor, front contact of relay Ssr, front contact of relay Fir, front contact of relay Fhr, winding of relay Kir, battery.
  • Relay Kir energizes relay Vrr, which releases relays Ftr and Fhr.
  • Relay Kzr is bound to release as soon as the armature of relay F 1' leaves the front contact, so that relay Vrr releasing reestablishes the alternating current test conditions as before.
  • the power magnet of the group selector is again energized and the brush carriage continues to hunt for another free outlet in the wanted group.
  • the direct current test cannot be successful if the selector is stopped with some delay, so that the brush is opened, or in case the test potential is kept busy by a circuit, which has just tested the same alternating current, or another reason may be that the fuse of the outlet engaged is missing.
  • relay Tr does not operate, due to which relay Cbr is energized.
  • Relay Cbr disconnects the test relay Tr and directs the 1) wire to the control cathode of the cold cathode tube GT4. At the same time it energizes the power magnet of the selector over the a wire.
  • the brush carriage leaves the position in which the direct current test was not successful and will have to advance until it reaches the-first free test potential of any free outlet.
  • the control anode of tube CT i is permanently connected to about 30 v. positive battery.
  • the tube therefore will not light on busied test potential, because the 30 volts is not sufficient to break down.
  • relay Fsr operates and stops the selector on the terminals of a free outlet which, of course, does not necessarily belong t the same group as the outlet tested before.
  • Relay Fsr energizes relay Vrr, which now in the known manner causes the release of the relays Fhr, Ftr, Tor as well as relays Chr and Vtr.
  • relay Tor The release of relay Tor is followed by that of relay Cbr, whereupon the tube GT4 is extinguished and relay Fsr releases.
  • the circuit is now ready to start again the A. C. test. If, therefore, the group selector is at that moment behind the group indicated by the reference current, the selector switch will have to start rotating its brushes again.
  • the selection in the third group selector is performed in the manner described above.
  • SM is now standing in position 2, and transformer H02 is connected to the brush (1 of ICF over which the reference current of the hundreds digit is reached.
  • the selection terminates again by the operation of relay Sar and the step-by-step switch SM is advanced to position 3.
  • the final selector will have to stop when the calling tone is found on the 0 wire of the subscriber to be identified. This tone is detected by the tube CTI, and relay Ttr consequently has to stop the final selector.
  • the tone is checked in thefollowing circuit: primary winding of transformer ITI, front contact of relay Olcr, the transformer 1T2, front contact of relay For, resistance R, back contact of relayBtr, b wire over second and third group selector, back contact of relay Br (in final), front contact of relay Ar, winding of relay Br, brush 0 of final selector, 0 terminals, sources of alternating current.
  • Transformer 1T2 replaces T on the first tone test.
  • relay Ttr operates, a timed check is introduced in order to ascertain that the final selector has stopped on the calling tone. This check, which consists in the repeated release of the tube CTl, has been described in connection with the test on the common point.
  • Ctr releases Btr operates, since relay For is energized now.
  • Relay Btr opens the tone test circuit, so that relay Kcr is then released on the next opening of the interrupter IS.
  • Magnet SM is energized in the circuit: ground, interrupter, back contact of SM, front contact of relay For, front contact of relay Btr, magnet SM, battery.
  • the step-by-step switch TM registers the number of times the final selector passes over a sub-normal position, this being the indication of the tens digit of the subscribers number. This counting is carried out with the help of the receiving equipment.
  • Transformer H02 is connected via terminal 3 of the SM to the brush 1) of TM.
  • the reference currents connected to this arc b are identical to the currents connected to the sub-normal positions of the final selector.
  • the signaling circuit is completed in the known way, like it was for selection purposes.
  • relay Vtr operates. Relay Lsr being new energized, a circuit is closed for relay Tmr, which looks itself to the interrupter contact of TM.
  • Relay Tmr energizes relay Vrr, whereupon relay Chr releases, tube GT2 extinguishes and relay Vtr releases. If TM is already fully energized, relay Tmr releases and TM takes one step. Relay Vrr releases and when relay Chr re-operates, the final selector switch will have already passed the subnormal position and a record of this will have 13 been made by the one step taken by TM. When the next sub-normal position is reached, the phase of whichcorresponds to the phase connected to terminal -I of the are b of TM, Vtr operates again and one step is taken by TM.
  • Relay Icr locks itself via the back contact of relay Edr. IS starts its rotation and produces impulses.
  • the first closure which may be partial, energizes relay Fir, and during the following opening relay Flr energizes in series with relay Fir.
  • the sending tone T2 is connected as follows: Source T2, front contact of relay Flr, filter F2, back contact of relay Sir, front contact of relay Btr, b'wire over second and third group selector, back contact of relay Br (in the final selector), front contact of relay Ar, winding of relay Br, brush of the final selector, 0 Wire over line finders, etc. to the tone detector in the junction circuit,
  • Relay 'Isr follows the impulses of IS and steps the switch CM.
  • the length of the starting impulse is equal to about the time required for three and .a half impulses.
  • the stepping of CM is stopped by the receiving equipment.
  • the reference current circuit terminates via brush b of SM, position 4, at the alternating current source of "the third phase.
  • the signaling current is changed from phase to phase on arc b of CM, whilst this switch is advanced step-by-step.
  • the identity of the signaling and reference currents causes the operation of relay Vtr. Due to the operated relay Dsr, relay Edr is also energized. This relay Ed?
  • relay Ifr which relay, together with relay Mr, is kept energized, whilst impulse sending takes place.
  • Relay Eclr opens the impulse "circuit and releases relay for.
  • the relays Fir, Flr release instantaneously, whereas the relays Idr and Ifr release slowly.
  • the releasin time of the two latter relays has to cover the inter-digital time separating two consecutive digits.
  • step-by-step switch GM returns to its normal position via its interrupter contact and are a.
  • Relay Edr energizes relay Sar.
  • This relay Sar operates relay Vrr in order to extinguish tube GT2 -and at the same time the magnet SM is energized.
  • relay Edr releases as do the relays S'ar and Vrr.
  • the receiving equipment is ready to control the sending of the first digit. This starts by the re-operation of relay Icr, and is performed in the same way as the sending of the starting impulse.
  • relay Sir is operated via terminal 5 of are d of SM and consequently the short-circuit on the impulse contact of relay Iscr is removed.
  • all the subsequent impulses are reproduced by relay Ixr on the impulse sending path towards the indentification calling circuit.
  • the reference current is changed on the arc in of SM. In position 5 a digit is sent out, the
  • the tens digit is stored by TM,
  • the reference current correspondingly is taken in position 8 via arc c of TM.
  • position 9 the units are sent out.
  • the value of this digit is fixed by the position of the final selector and is signalled by the alternating current available over brush d of the final selector.
  • This alternating current is connected via wire c, via front contact of relay DST and over terminal 9 of are D of SM to the reference transformer I-ICZ.
  • the signalin current is changed on are I) of CM as before, with the only difference that the alternating current source of phase I is changed on relay Usr operated for this sending to the alternating current source corresponding to the sub-normal position, which is eventually occupied by the final selector.
  • SM When the units digit is sent out, SM arrives at position 10 and energizes relay Rlr, which opens the locking ground of relay Old?" and initiates thereby the release of the circuit.
  • the relays engaged release in sequence: Ggr, Ghr, B251", etc.
  • Relay Ghr closes the homing circuit of SM and Tm, whereupon both switches return to their normal position under the control of their interrupter contacts.
  • Relay Olcr closes the homing circuit of ICF, which switch therefore returns to normal.
  • the holding ground of the second group selector is opened, when relay Okr releases.
  • the second group selector releases the third group selector and this in turn liberates the final selector, which circuits have been engaged temporarily for identification purposes.
  • step-by-step switch TM receives more than ten impulses. Arriving in position 10, TM prepares an operating circuit for relay RZr via are (2 position 10. If relay Tmr operates now indicating an 11th impulse, Rlr is energized and the indentification control circuit is released.
  • a plurality of groups of lines each designated by a different number means including non-numerical switches and numerical group and final selectors for establishing a connection between a calling and a called line, equipment for identifying the number of the calling line, different sources of characteristic A.
  • C. potentials means for opcrating at least one of said group selectors and a final selector to connect said equipment with the calling line, means to connect the equipment with the calling line over the non-numerical switch employed in the establishment of said connection, connections from said sources to the last men- 15 tioned means, and means in said equipment responsive to said A. C. potentials.
  • roups of lines each designated by a different number
  • means including non-numerical switches and numerical group and final selectors for connecting'a calling with a called line, said selectors having terminal banks and brushes movable from a home position over the terminals, equipment for identifying the number of the callin line, two groups of different sources of characteristic A.
  • each group representing a different digit of line numbers
  • an access finder having contacts connected with the equipment and cooperating contacts, the latter connected with said non-numerical switches and said two groups of sources, means in said equip ment variably responsive to said sources, circuits controlled by said equipment for operating at least one group selector to select a final selector, means also controlled by said equipment for operatin the last mentioned final selector to hunt for the terminals of the calling line, and means controlled by the last mentioned final selector to signal to said equipment the location of said calling line terminals with respect to the home position of the final selector.
  • a plurality of groups of lines each designated by a different number means including non-numerical switches and numerical group and-final selectors for connecting a calling with a called line, said selectors having terminal banks and brushes movable from a home position over the terminals, equipment for identifying the number of the calling line, sources of characteristic potentials having differences in at least one of their electrical characteristics, said sources representing a digit of a line number, means for applying the potential from each source to a point common to a plurality of lines including the calling line to be iden tified, means for operating at least one group selector in accordance with one digit of the calling line number to select a final selector, means for operating the last mentioned final selector to select the terminals of the calling line to Which the potential has been applied, and means in the identificatio-n equipment for counting the number of terminals passed over by the brushes of the final selector when moving from the home position to the terminals of the line to be identified.
  • a plurality of groups of lines each designated by a different number means including non-numerical switches and numerical group and final selectors for connecting a calling with a called line, said selectors having terminal banks and brushes movable from a home position over the terminals,
  • 16 equipment for identifyin the number of the calling line, sources of characteristic potentials having difierences in at least one of their electrical characteristics, said sources representing a digit of a line number, means for applying the poten tial from each source to a point common to a plurality of lines including the calling line to be identified, means for operating at least one group selector in accordance with one digit of the calling line number to select a final selector, means for operating the last mentioned final selector to select the terminals of the calling line to which the potential has been applied, and means in the identification equipment for counting the numberof terminals passed over by the brushes of the final selector when moving from the terminals'of the line to be identified to the home position.
  • a plurality of groups of numerically designated lines means including a line finder, and a plurality of stages of group selectors, a final selector for connecting a calling with a called line, said finder and said selectors having banks of terminals and cooperating sets of brushes, each line having conductors connected in multiple to terminal banks of final selectors and line finders, identification equipment for identifyin the number of the callin line, an access finder associated with the identification equipment and having terminals and a set of brushes cooperating therewith, two groups of sources of current differing in at least one of their electrical characteristics and representing two digits of line numbers, connections from one group of sources to one and from the other group to other terminals of the access finder, means including a group selector and a final selector for connecting the identification equipment with the calling line, and means including said sources of current for controlling the operations of the last mentioned group selector.
  • a plurality of numerically designated lines means including a line finder, group selectors and a final selector for connecting a calling with a called line, said line finder and selectors having banks of terminal groups and brushes movable over the terminals, magnets for moving said brushes, each line'having conductors connected in multiple to the terminals of final selectors arranged in groups and to the terminals of a line finder, equipment for identifying the number of the calling line, a connection from said equipment to the brushes of one of the selectors, a different source of characteristic A, C.
  • a plurality of numerically designated lines means including a line finder, group selectors and a final selector for connecting a calling with a called line, said line finder and selectors having banks of terminal groups and brushes movable from a home position over the terminals, magnets for moving said brushes, each line having conductors connected in multiple to the terminals of final selectors arranged in groups and to the terminals of the line finder, equipment for identifying the number of the calling line, a connec tion from said equipment to the brushes of one of the group selectors, a different source of characteristic A. C.
  • a control circuit for said access finder including a brush thereof and responsive to said one frequency to move the brushes into engagement with terminals connected with the calling line over the brushes of the line finder, means operative thereupon for actuating the magnet of the group selector connected with the equipment, a circuit for the last mentioned magnet actuated only if a predetermined relationship exists between the signaling current source with which the last mentioned group selector brushes are connected over the terminals thereof and the reference current source representing the corresponding digit with which one of the access finder brushes is connected over a terminal of the latter, a circuit for the magnet of another selector selected by the last mentioned selector actuated only if a predetermined relationship exists between the signaling current source with which said another selector brushes contact and the reference current source with which another access finder brush contacts, a control circuit for the magnet of the final selector including brushes of the latter and of the line finder and said group selector of the connection and the A.
  • ' means including 'b, first and a second line finder
  • group selectors of a first, a second and a third stage, and a final selectorfor connecting a calling with a called line said line finders and sel'etor's fhavirig banks of terminal "groups and brushes movable from a home pos'ition over the terminals, magnets for moving said brushes, each line having conductors connected in multiple to the terminals of final selectors arranged in groups and. to the terminals of a first lin finder, equipment for identifying the number of the calling line, a connection from said equipment to the brushes of one of the second group selectors, a 'difierent source of characteristic A.
  • a control circuit for said access finder including a brush thereof and responsive to said one frequency to move the brushes into engagement with terminals connected with the calling line over the brushes of the first line finder, means operative thereupon for actuating the magnet of said one of the group selectors of the second stage, a circuit for the last mentioned magnet actuated only if a predetermined relationship exists between the thousands signaling current source with which said second stage group selector brushes are connected over the terminals thereof and the reference current source representing the thousands digit with which one of the access finder brushes is connected over a terminal of the latter, a circuit for the magnet.
  • a control circuit for the magnet of the final selector including brushes of the latter and of the first and second line finders and first group selector of the connection and said A.
  • source of one frequency said control circuit being responsive to the latter, means in the identifying equipment for counting the number of terminal groups traversed by the final selector brushes before they encounter the terminal of the calling line, an impulse sender associated With said equipment comprising an A.

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Devices For Supply Of Signal Current (AREA)
  • Testing Of Short-Circuits, Discontinuities, Leakage, Or Incorrect Line Connections (AREA)
US486273A 1941-08-21 1943-05-08 Calling line identification system Expired - Lifetime US2440277A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
NL255843X 1941-08-21

Publications (1)

Publication Number Publication Date
US2440277A true US2440277A (en) 1948-04-27

Family

ID=19781301

Family Applications (1)

Application Number Title Priority Date Filing Date
US486273A Expired - Lifetime US2440277A (en) 1941-08-21 1943-05-08 Calling line identification system

Country Status (6)

Country Link
US (1) US2440277A (fr)
BE (1) BE447417A (fr)
CH (1) CH255843A (fr)
FR (1) FR885486A (fr)
GB (1) GB597688A (fr)
NL (1) NL59752C (fr)

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2535513A (en) * 1946-02-23 1950-12-26 Automatic Elect Lab Testing device for line identifying equipment
US2535446A (en) * 1948-06-16 1950-12-26 Bell Telephone Labor Inc Carrier communication system
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
US2554149A (en) * 1948-07-08 1951-05-22 Bell Telephone Labor Inc Translator for calling line identification
US2570971A (en) * 1947-11-14 1951-10-09 Bell Telephone Labor Inc Vertical line number translator
US2619545A (en) * 1947-06-13 1952-11-25 Bell Telephone Labor Inc Telephone calling line identification and recording system
US2879338A (en) * 1953-02-09 1959-03-24 Bell Telephone Labor Inc Identification system

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1846261A (en) * 1931-04-11 1932-02-23 American Telephone & Telegraph Telephone system
US1846516A (en) * 1931-06-05 1932-02-23 American Telephone & Telegraph Telephone system
US1944244A (en) * 1930-12-06 1934-01-23 Bell Telephone Labor Inc Telephone system
US2222099A (en) * 1938-11-07 1940-11-19 Fides Ges Fur Verwaltung Und V Telephone system
US2244700A (en) * 1939-09-21 1941-06-10 Bell Telephone Labor Inc Telephone system
US2267950A (en) * 1940-09-20 1941-12-30 Bell Telephone Labor Inc Telephone system

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1944244A (en) * 1930-12-06 1934-01-23 Bell Telephone Labor Inc Telephone system
US1846261A (en) * 1931-04-11 1932-02-23 American Telephone & Telegraph Telephone system
US1846516A (en) * 1931-06-05 1932-02-23 American Telephone & Telegraph Telephone system
US2222099A (en) * 1938-11-07 1940-11-19 Fides Ges Fur Verwaltung Und V Telephone system
US2244700A (en) * 1939-09-21 1941-06-10 Bell Telephone Labor Inc Telephone system
US2267950A (en) * 1940-09-20 1941-12-30 Bell Telephone Labor Inc Telephone system

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2535513A (en) * 1946-02-23 1950-12-26 Automatic Elect Lab Testing device for line identifying equipment
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
US2619545A (en) * 1947-06-13 1952-11-25 Bell Telephone Labor Inc Telephone calling line identification and recording system
US2570971A (en) * 1947-11-14 1951-10-09 Bell Telephone Labor Inc Vertical line number translator
US2535446A (en) * 1948-06-16 1950-12-26 Bell Telephone Labor Inc Carrier communication system
US2554149A (en) * 1948-07-08 1951-05-22 Bell Telephone Labor Inc Translator for calling line identification
US2879338A (en) * 1953-02-09 1959-03-24 Bell Telephone Labor Inc Identification system

Also Published As

Publication number Publication date
CH255843A (de) 1948-07-15
BE447417A (fr)
GB597688A (en) 1948-02-02
FR885486A (fr) 1943-09-16
NL59752C (fr)

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