US2693503A - Electric dialing circuit - Google Patents

Electric dialing circuit Download PDF

Info

Publication number
US2693503A
US2693503A US285408A US28540852A US2693503A US 2693503 A US2693503 A US 2693503A US 285408 A US285408 A US 285408A US 28540852 A US28540852 A US 28540852A US 2693503 A US2693503 A US 2693503A
Authority
US
United States
Prior art keywords
tube
point
ignition
voltage
tubes
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
US285408A
Other languages
English (en)
Inventor
Six Willem
Domburg Jacobus
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.)
Hartford National Bank and Trust Co
Original Assignee
Hartford National Bank and Trust Co
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 Hartford National Bank and Trust Co filed Critical Hartford National Bank and Trust Co
Application granted granted Critical
Publication of US2693503A publication Critical patent/US2693503A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • 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
    • H04Q3/52—Circuit arrangements for indirect selecting controlled by common circuits, e.g. register controller, marker using static devices in switching stages, e.g. electronic switching arrangements
    • H04Q3/525—Circuit arrangements for indirect selecting controlled by common circuits, e.g. register controller, marker using static devices in switching stages, e.g. electronic switching arrangements using tubes in the switching stages

Definitions

  • This invention relates to electronic dialling circuits for automatic signalling systems, for example, telephone systerns, for the numerical establishment of a connection be tween one of a plurality of apparatus of a first kind, for example a connecting circuit, and one of a plurality of apparatus of a second kind, for example a subscribers line circuit or a subsequent dialling stage, each having associated with it a number or a figure.
  • a circuit has been suggested, in which such a connection may be established with the use of gas-filled discharge tubes, for example, cold cathode tubes.
  • a multipled point of each apparatus of the first kind is connected by way of an impedance to a first terminal of a source of supply and also coupled by way of a discharge path of a gaseous tube to a multipled point of each apparatus of the second kind.
  • Each multipled point t is connected by way of an impedance to a second terminal of the source of supply.
  • the difference in potential between the terminals of the source of supply is smaller than the ignition voltage of the discharge paths, but greater than the operating voltage.
  • a marking circuit for receiving dialling signals transmitted by a subscriber, an input control-point of said marking circuit being connected to the multipled point of the apparatus of the first kind, which point may have supplied to it dialling pulses.
  • a plurality of marking output points are coupled to ignition electrodes of the gaseous tubes, which are connected to the multipled point of the apparatus of the first kind.
  • the voltage of the marking point connected to the ignition electrodes of the gaseous tube associated with an apparatus of the second kind corresponding to the number is increased as a function of the number dialled to such extent that the gaseous tube concerned may become conductive if the apparatus is free, that is to say, if none of the other gaseous tubes connected to the multipled point of the said apparatus is conductive.
  • the gaseous tube cannot become conductive if the apparatus is busy, since in this case the voltage of the multipled point differs from the voltage of the second terminal of the source of supply and is active at at least one of the electrodes of the gaseous tube, for
  • the ignition electrode or the cathode in such manner that the ignition voltage cannot be exceeded.
  • an electronic counting circuit for example a counting circuit comprising gaseous tubes or an electron-beam counting tube, as a marking switch.
  • an electronic counting circuit for example a counting circuit comprising gaseous tubes or an electron-beam counting tube.
  • steps must be taken to avoid undesired ignition of a gaseous tube during a series of dialling pulses or upon occurrence of pulses at the multipled point of the apparatus of the first kind due, for example, to the extinction or ignition of a gaseous tube or to a call being answered.
  • the object of the invention is to avoid the above-described drawbacks and to provide an improved elec- Provision is also I) a gas-filled tube to a common point P of each of a plurality of connecting circuits.
  • the figure shows only three subscribers stations AA, AB, AC with the associated line current paths LCA, LCB, LCC and a single connecting circuit VC.
  • the line current paths of lines which are not shown, are exactly similar to the line circuits LCA, LCB, LCC, whilst the coupling of the subscribers station AA, AB, AC with connecting circuits which are not shown is eifected in a manner exactly similar to the coupling with the connecting circuit VC.
  • Each subscribers station AA, AB, AC is connected across two primary windings of a transformer TA, TB, TC, respectively, the junction between the two primary windings of a transformer being by way of a source of supply V2.
  • One of the extremities of a secondary winding of TA, TB, TC is connected to earth by way of a parallel combination of a resistor Rm, R11), R10 and a capacitor Cm, C11,, Cm, respectively.
  • the otherextremity of the secondary winding is connected to the cathode k of the gaseous tube BA, BB, BC, through which the line is coupled to the connecting circuit VC.
  • the cathodes of gaseous tubes (not shown) by which the lines are coupled to the other connecting circuits, are connected in a similar manner to the multipled points A, B, C of the line circuits.
  • the anode a of the tube BA, BB, BC is connected to the common point P in the connecting circuit VC, which point is connected by way of an inductor L1 and the parallel combination of resistor R1 and capacitor C1 to the point of supply V1, the potential of which is higher than the operating voltage of the gas-filled tube BA, BB, BC, but lower than the ignition voltage between cathode k and anode a.
  • the ignition voltage is for example, 170 volts and the operating voltage is 60 volts.
  • the voltage V1 may then, for example, be 140 volts.
  • Each gas-filled tube BA, BB, BC comprises two ignition electrodes f1 and f2.
  • the ignition voltage between the ignition electrodes f1 or f2 and the cathode of a tube is 70 volts.
  • the ignition electrodes f1 are connected to tappings on high-ohmic voltage dividers R421, R5a, and R41), R b and R46, Rsc, respectively, which are included between a junction point Q, between inductor L1 and resistor R1, and supply source V7, such that the difference in potential between each ignition electrode f1 and the associated cathode k is slightly lower than the ignition voltage, if none of the tubes BA, BB, BC connected to point P is conductive.
  • the normal voltage of the ignition electrodes fl is, for example, 80 volts.
  • the normal voltage of the ignition electrodes f2 is equal to earth ,potential and hence much lower than the normal voltage of the ignition electrodes f1.
  • the tubes BA, BB, BC may serve to establish a connection between a calling line and a connecting circuit and also for the numerical establishment of a connection between the connecting circuit and a calling line.
  • the ignition electrodes h of tubes BA which couple the multipled point A to busy connecting circuits VC, have a lower potential, since the potential of the points Q of the said connecting circuits is lower than that of V1, which prevents the tubes from being ignited.
  • the main discharge path between the cathode k and the anode a of this tube BA also ignites, so that current starts to flow from the supply point V1 by way of resistor R1, inductor L1, common point P, discharge path between anode a and cathode k of the tube BA, multipled point A, secondary winding of transformer TA, and resistor Rm to earth.
  • the increase in the potential of point A results in the difference in potential between the cathode k and the ignition electrode f1 of the tubes BA becoming smaller than the ignition voltage, so that the said other tubes cannot ignite. Consequently, one tube BA only is ignited.
  • the potential of the ignition electrode f1 of the tubes which couple the connecting circuits to other subscribers lines also decreases. Consequently, it is avoided that upon a subsequent call by one of the other subscribers, one of the said tubes could ignite and this subscriber could also engage the connecting circuit VC, in other words the connecting circuit is marked busy by the decrease in the potential of point Q.
  • the subscriber AA subsequently dials the desired number, in this case the figure 3.
  • the subscribers dial is shunted by an impedance (not shown).
  • the line loop is interrupted incompletely, so that the pulses which occur, during dialling, across the primary winding of transformer TA are smaller than the pulses which occur across the primary winding by closing or opening the line loop when the telephone is removed or replaced.
  • a positive pulse occurs at the beginning of each dialling pulse and a negative pulse occurs at point A at the end of each dialling pulse.
  • the amplitude of said pulses is approximately volts.
  • the pulses are transferred by way of the discharge path between cathode k and anode a of tube BA and inductor L1 to the point Q and thence transferred by way of a capacitor C9 to the control grid of a vacuum amplifying tube B1, by which said pulses are amplified and supplied with opposite polarity to a point U.
  • the cathode of tube B1 is connected to earth by way of a resistor R3, the anode being supplied by way of resistor R2 from the source of supply V1.
  • the positive pulse is supplied by way of capacitor C2 to the ignition electrode 1 of a gasfilled discharge tube B4, which electrode is connected by way of resistor R4 to a source of supply V3, the voltage of which is such that the gaseous tube B4 becomes conductive if a small positive pulse is supplied to the point U.
  • the positive pulse at the point U is furthermore supplied by way of capacitor C3 and resistor R5 to the ignition electrode 7 of a gas-filled discharge tube B5, which ignition electrode is coupled by way of resistor R6 to a source of supply V4, the voltage of which is so much lower than that of the source of supply V3 that the tube B5 can ignite only with a much stronger positive pulse at the point U. Consequently, tube Bs does not ignite upon reception of dialling pulses.
  • the anode a of tube B4 is connected to the source of supply V1.
  • the gaseous tube B4 becomes conductive with the first dialling pulse.
  • the cathode of this tube is connected to earth by way of an impedance Z4, constituted by an inductor in series with a resistor shunted by a capacitor.
  • the elements of said impedance are chosen to be such that the gaseous tube B4 cannot operate in a stable manner, but extinguishes again immediately after ignition.
  • Similar impedances Z2, Z3, Z5 are included for the same purpose in the cathode leads of the gas-filled discharge tubes B2, B3, B5.
  • the anodes a of the tubes B11, B12, B13, Bln are connected to the source of supply V1, the cathodes It being connected by way of resistors R11, R12, R13, R1 to a common point W, which is connected to earth by way of a resistor R33.
  • the ignition electrode 1 of tubes B11 is connected to a tapping point on a voltage divider R31, R32, included between earth and the source of supply V1.
  • the cathodes k of the tubes B11, B12, B13, Bin are coupled by capacitors C21, C22 etc.
  • the ignition electrodes 1 of the tubes B12, B13 etc. are connected by way of resistors R21, R22 etc. to the cathode of the preceding tube.
  • the gaseous tubes are cut off in the normal condition of the circuit, the control electrode f of tube B11 having a potential higher than that of the ignition electrodes of the other tubes.
  • the tube B11 After the first dialling pulse, the tube B11 only has become conductive and tube B12 is prepared for subsequent ignition.
  • the tube B12 does not ignite with the first dialling pulse, since upon an increase in the potential of the cathode of tube B11 a positive voltage pulse is supplied to both the cathode of tube B12 by way of capacitor C21 and to the ignition electrode of tube E12 by way of resistor R21, said pulsess counteracting one another.
  • the tube B4 With the second dialling pulse, the tube B4 becomes conductive for the second time and supplies a second positive pulse by way of capacitors C11, C12, C13 etc. to the ignition electrodes 7 of all gaseous tubes of the counting circuit MS. Since the ignition electrode of tube B12, as a result of the increase in potential of the cathode of tube B11, now has the highest potential of the ignition electrodes of the counting tubes, the gaseous tube B12 becomes conducting with the second counting pulse, with the result that the potential of the cathode k of tube B12 increases. Now, a positive voltage pulse is transferred by way of capacitor C21 to the cathode k of tube 811, so that this tube extinguishes.
  • the ignition electrode f of tube B12 has the highest potential of the ignition electrodes, since this ignition electrode is coupled by way of resistor R22 to the cathode of tube B12, so that tube B13 is now prepared for subsequent ignition. Similarly, with the third dialling pulse, tube B13 is ignited and tube B12 extinguishes.
  • tube B11 is conductive after one dialing pulse
  • tube B12 is conductive after two dialling pulses
  • tube B12 is conductive after two dialling pulses
  • tube B13 after three dialling pulses, etc.
  • Each tube thus corresponds to a determined figure.
  • Each ignition electrode f2 of the tubes BA, BB, etc. is coupled by way of an integrating network constituted by resistors Rza, R32 and capacitors C22, C321 and resistors R21), R31: and capacitors C211, Cab etc. respectively, to the cathode of the tube of the counting circuit MS which numerically corresponds to the number of the line with which the tube BA or BB is associated.
  • the ignition electrode 2 of tube BB which corresponds to the subscribers station AB and which has associated with it the number 3 is coupled to the oathode of tube B13, which is ignited after three dialling pulses.
  • the ignition electrodes f2 of the tubes BC and BA which correspond to subscribers stations having associated with them, the numbers 1 and 2 are coupled to the cathodes of the tubes B11 and B12 respectively.
  • the voltage of the point W and hence the voltage of the cathodes of the other tubes is 40 volts. This voltage is lower than the ignition voltage between ignition electrodes 1 and cathode k of the tubes BA, BB, BC.
  • the voltage of the cathode of the conductive tube is 80 volts and hence higher than the said ignition voltage.
  • Tube BC does not ignite, however, since the voltage of the ignition electrode f2 cannot suddenly change to 80 volts, but can increase only comparatively slowly as a result of the integrating action of the network RZc,
  • the station AB is busy.
  • One of the tubes (not shown), of which the cathodes are connected to the point B, is then in a conductive condition, so that the voltage 01' point B is either 40 volts or 27 volts, according to whether the subscriber at station AB is dialling or is otherwise busy.
  • the voltage of the ignition electrode f2 of tube BB has increased to 80 volts, only a voltage of 40 volts or 53 volts, i. e. a voltage lower than the ignition voltage, is set up between the ignition electrode f2 and the cathode k, so that tube BB cannot ignite.
  • the subscriber at station AA then receives busy tone.
  • 'A tapping point S on the inductor L1 is connected by way of capacitor C8 and a rectifier g1 to one extremity of a winding of a transformer TG, the other extremity of which is connected to a source of supply Vs, the voltage of whichis 20 volts.
  • Another winding of transformer TG is connected to a common busy-tone generator GB.
  • the junction between capacitor C3 and rectifier g1 is connected bywayof resistor R34 to the point W. So long as the counting circuit MS is in its normal position, the voltage of the point W is equal to earth potential and rectifier g1 is cut off. However, if one of the tubes ofthe counting circuit MS is conductive, the voltage of point W is 40 volts and rectifier g is conductive.
  • the generator GB then supplies busy tone to subscriber AA by way of rectifier g1, capacitor C8, inductor L1, tube BA and transformer TA.
  • a strong positive pulse is produced in the secondary winding of the transformer TA due to the line loop being opened.
  • this closing pulse is of such strength that the tube BA extinguishes, so that a strong positive pulse occurs at points Q. If, for example, as a result of a high resistance of the line, the pulses at point A were not sufiiciently strong to extinguish the tube immediately, the tube transfers the pulse to point Q, so that even in this case a strong positive pulse occurs at point Q.
  • the closing pulse is transferred by tube B1 with opposite polarity to the point U and thence transferred by way of a capacitor C5 and a rectifier g2 to the oathode of tube B3.
  • the ignition electrode f of tube B3 is connected to a source V5 of a voltage such that tube B3 ignites if a strong negative pulse such, for example, as occurs when the receiver is replaced, is supplied to the cathode, but cannot become conductive with a comparatively weak pulse such, for example, as occurs with a dialling signal.
  • tube B4 due to the ignition of tube 133, a strong positive pulse is supplied by way of rectifier g2 and capacitor C5 to the point U and thence transferred by way of capacitor C2, to the ignition electrode 1 of tube B4 and by way of capacitor C3 and resistor R5 to the ignition electrode 1 of tube B5.
  • the tubes B4 and B5 are thus ignited.
  • Tube B4 ignites somewhat later than tube B5, since the pulse to the ignition electrode of tube B5 is somewhat retarded by the presence of the network R5, C4.
  • the ignition of tube B41 causes a subsequent tube in the counting circuit MS to become conductive in the manner which has already been described.
  • a tube which couples point P to another subscribers line cannot thus ignite, since tube B5 also becomes conductive a short time after tube B4.
  • tube B5 results in a strong positive pulse at point W, by which the voltage of the cathode of the conductive tube in the counting circuit is suddenly increased to such extent that this tube ex tinguishes and the counting circuit MS is returned to its normal position.
  • the tubes B2, B3, B4, B5 re-extingalish automatically after their ignition due to the presence of the impedances Z2, Z3, Z4, Z5 in their cathode leads. All gas-filled tubes are thus extinguished and the circuit is returned to its normal position.
  • the closure of the line loop results in a negative voltage pulse at the point P, which is transferred by way of inductor L1 to the point Q and is further transferred by tube B1 with opposite polarity to the point U.
  • the positive pulse at the point U causes ignition of the tubes B2 and B3 in the manner already described, so that tube B11 becomes conductive and immediately extinguishes again due to the ignition of tube B5.
  • the desired connection betwen the subscribers at stations AA and AB is thus established and intelligence currents may be transmitted in either direction by way of transformer TA, the main discharge paths of tubes BA, BB and transformer TB.
  • An electronic dialing circuit in automatic signaling system for numerically establishing a connection between one of a plurality of apparatus of a first kind and one of a plurality of apparatus of a second kind comprising a first multipled point coupled with each apparatus of said first kind, a first impedance interposed between said first multipled point and a first terminal of a source of supply, a second multipled point coupled with each apparatus of said second kind, a plurality of gas-filled tubes having ignition electrodes, said tubes being parallelly connected and interposed between said second multipled point and said first multipled point, a second impedance interposed between said second multipled point and a second terminal of said source of supply, the difference in potential between said first and second tenninals of said source of supply being lower than the ignition voltage and higher than the operating voltage of said gas-filled tube, a calling line providing intelligence currents and dialing pulses coupled to said first multipled point, said apparatus of the first kind including an electronic counting circuit having a plurality of output marking points and means coupled to said first multipled point for
  • An electronic dialing circuit as set forth in claim 1, wherein said means for applying impulses includes an amplifier and a pulse limiting circuit coupled thereto.
  • An electronic dialing circuit as set forth in claim 1, further including means for restoring said counting circuit to its normal condition, said means responding when a pulse of a strength exceeding a predetermined threshold value occurs at said first multipled point, said threshold value being higher than the maximum value of said dialing pulses.
  • said counting circuit comprises a plurality of additional gas-filled tubes and a common impedance coupled to the outputs of said additional tubes and a further gas-filled tube having a control electrode coupled to said first multipled point and an output electrode coupled to said common impedance.
  • said means for restoring said counting circuit to its normal condition responds to a pulse which occurs at the first multipled point upon ignition of one of said plurality of gas-filled tubes.
  • An electronic dialing circuit as set forth in claim 1, further including a busy tone generator and a circuit element coupling said generator to said first multipled point, said circuit element being controlled by said counting circuit to provide busy tone to said first multipled point only when said counting circuit has a condition other than the normal condition.
  • An electronic dialing circuit as set forth in claim 2, further including means coupled to said first multipled point and responsive to a first pulse of opposite polarity to that to which said counting circuit responds, said latter means supplying a second pulse to said first multipled point for extinguishing one of said plurality of gas-filled tubes, said second pulse having the same polarity as that to which said counting circiut responds and having a strength exceeding a predetermined threshold value, said threshold value being higher than the maximum value of said dialing pulses.
  • said latter means includes said amplifier coupled to said first multipled point, a first auxiliary gasfilled tube having a first cathode, a rectifier interposed between said amplifier and said cathode, a second auxiliary gas-filled tube having a second cathode, an ignition electrode coupled to said first cathode and an anode coupled to said first multipled point, and an impedance coupled to the cathodes of each of said auxiliary tubes whereby said auxiliary tubes operate in an unstable manner.

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Telephonic Communication Services (AREA)
  • Devices For Supply Of Signal Current (AREA)
US285408A 1951-05-23 1952-05-01 Electric dialing circuit Expired - Lifetime US2693503A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
NL302754X 1951-05-23

Publications (1)

Publication Number Publication Date
US2693503A true US2693503A (en) 1954-11-02

Family

ID=19783370

Family Applications (1)

Application Number Title Priority Date Filing Date
US285408A Expired - Lifetime US2693503A (en) 1951-05-23 1952-05-01 Electric dialing circuit

Country Status (7)

Country Link
US (1) US2693503A (it)
BE (1) BE511611A (it)
CH (1) CH302754A (it)
DE (1) DE912824C (it)
FR (1) FR1063848A (it)
GB (1) GB707504A (it)
NL (1) NL80837C (it)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB967252A (en) * 1960-05-25 1964-08-19 Pye Ltd Automatic telephone systems

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2434989A (en) * 1943-08-13 1948-01-27 Siemans Brothers & Co Ltd High-speed searcher using gas discharge tubes
US2562100A (en) * 1948-11-17 1951-07-24 Bell Telephone Labor Inc Coordinate selecting and lock-out circuit
US2598392A (en) * 1947-01-03 1952-05-27 Ericsson Telefon Ab L M Gaseous tube selecting switch for use in automatic telephony

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2434989A (en) * 1943-08-13 1948-01-27 Siemans Brothers & Co Ltd High-speed searcher using gas discharge tubes
US2598392A (en) * 1947-01-03 1952-05-27 Ericsson Telefon Ab L M Gaseous tube selecting switch for use in automatic telephony
US2562100A (en) * 1948-11-17 1951-07-24 Bell Telephone Labor Inc Coordinate selecting and lock-out circuit

Also Published As

Publication number Publication date
CH302754A (de) 1954-10-31
DE912824C (de) 1954-06-03
BE511611A (it)
GB707504A (en) 1954-04-21
FR1063848A (fr) 1954-05-07
NL80837C (it)

Similar Documents

Publication Publication Date Title
US2224677A (en) Signaling system
US2684405A (en) Telephone selecting system employing combined selecting and talking path gas-discharge tube and selective disconnection
GB656693A (en) Improvements in or relating to automatic telephone apparatus
US2951911A (en) Arrangement for automatic signalling system intended for transmitting voice-frequency calling signals
GB707760A (en) Improvements in or relating to selector circuits for use in automatic telephone-exchange and like systems
US2719250A (en) Electronic register circuit
US3133994A (en) Conference circuit for telephone switching systems
US2870261A (en) Arrangement of subscribers' circuits in electronic telephone exchanges
US2693503A (en) Electric dialing circuit
US2763722A (en) Busy tone circuit for automatic telephone systems
US2876285A (en) Transistor switching network for communication system
US2195317A (en) Telephone system
US2668931A (en) Electronic register for telephone switching systems
US2576097A (en) Automatic telephone selective switching system
US2739265A (en) Circuit-arrangement for use in automatic telephone system
US2288251A (en) Automatic toll switching telephone system
US2812384A (en) Automatic telephone system
US2697140A (en) Electronic testing system
US2790030A (en) Circuit-arrangement for use in automatic telephone systems
US2944114A (en) Communication switching system employing gas tubes
US2022030A (en) Signaling system
US2801369A (en) Circuit arrangement for use in automatic telephone system
US2846511A (en) Circuit-arrangement for use in an electronic automatic telephone exchange
US2004244A (en) Selective signaling system
US2208924A (en) Telephone system