WO1987000717A1 - Commutateur de lignes telephoniques - Google Patents

Commutateur de lignes telephoniques Download PDF

Info

Publication number
WO1987000717A1
WO1987000717A1 PCT/AU1986/000182 AU8600182W WO8700717A1 WO 1987000717 A1 WO1987000717 A1 WO 1987000717A1 AU 8600182 W AU8600182 W AU 8600182W WO 8700717 A1 WO8700717 A1 WO 8700717A1
Authority
WO
WIPO (PCT)
Prior art keywords
switch
line
circuit
control
input
Prior art date
Application number
PCT/AU1986/000182
Other languages
English (en)
Inventor
Peter Anton Goode
David Russell Stevenson
Original Assignee
International Standard Electric Corporation
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 International Standard Electric Corporation filed Critical International Standard Electric Corporation
Priority to DE3689653T priority Critical patent/DE3689653T2/de
Priority to KR1019870700234A priority patent/KR940011757B1/ko
Priority to JP61503791A priority patent/JPH0795773B2/ja
Priority to BR8606792A priority patent/BR8606792A/pt
Priority to GB8705311A priority patent/GB2187363B/en
Priority to AT86904037T priority patent/ATE101773T1/de
Priority claimed from AU59803/86A external-priority patent/AU580679B2/en
Publication of WO1987000717A1 publication Critical patent/WO1987000717A1/fr

Links

Classifications

    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03K—PULSE TECHNIQUE
    • H03K17/00—Electronic switching or gating, i.e. not by contact-making and –breaking
    • H03K17/08—Modifications for protecting switching circuit against overcurrent or overvoltage
    • H03K17/082—Modifications for protecting switching circuit against overcurrent or overvoltage by feedback from the output to the control circuit
    • H03K17/0826—Modifications for protecting switching circuit against overcurrent or overvoltage by feedback from the output to the control circuit in bipolar transistor switches
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04M—TELEPHONIC COMMUNICATION
    • H04M1/00—Substation equipment, e.g. for use by subscribers
    • H04M1/26—Devices for calling a subscriber
    • H04M1/30—Devices which can set up and transmit only one digit at a time
    • H04M1/31—Devices which can set up and transmit only one digit at a time by interrupting current to generate trains of pulses; by periodically opening and closing contacts to generate trains of pulses
    • H04M1/312—Devices which can set up and transmit only one digit at a time by interrupting current to generate trains of pulses; by periodically opening and closing contacts to generate trains of pulses pulses produced by electronic circuits
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04M—TELEPHONIC COMMUNICATION
    • H04M19/00—Current supply arrangements for telephone systems
    • H04M19/08—Current supply arrangements for telephone systems with current supply sources at the substations
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04Q—SELECTING
    • H04Q1/00—Details of selecting apparatus or arrangements
    • H04Q1/18—Electrical details
    • H04Q1/30—Signalling arrangements; Manipulation of signalling currents
    • H04Q1/38—Signalling arrangements; Manipulation of signalling currents using combinations of direct currents of different amplitudes or polarities over line conductors or combination of line conductors

Definitions

  • This invention relates to a telephone subset line switch sometimes known as a 'Line Interface Circui ' , which Incorporates an electronic hook- switch usually in integrated circuit form.
  • Line switches of the aforementioned type are known and described in detail in, for example, the specification of Australian Patent Application No. 21.775/83.
  • This specification describes a solid state switch for use as a hook-switch, comprising a field effect transistor whose gate/source potential is controlled by a bipolar transistor.
  • Such a solid state hook- switch has an advantage over conventional mechanical hook-switches when "on hook dialling" is required, in that, expensive mechanically interlocked switches can be avoided.
  • This specification discloses a solid state line switch for a telephone subset which may be controlled by one or more of the subset functions.
  • a telephone subset line switch comprising input terminal means for coupling to the line terminals of a telephone subset circuit, and output terminal means for connection to the transmission circuit of said telephone subset circuit, a first semiconduc- tor switch means having a controllable conductive path thereof serially connected between a first terminal of the said input terminal means and a first output of said output terminal means, a second semiconductor device having a controllable conductive path connected between the control element of the first semiconductor switch means and a second terminal of the Input terminal means, said second input and second output terminals being c ⁇ timon, and whose control element forms a first control input for coupling to con ⁇ trol means associated with said transmission circuit for controllably switching said telephone subsets loop current circuit.
  • Pig. 1 is a circuit diagram of one form of a line switch of the pres ⁇ ent invention
  • Pig. 2 shows a circuit diagram of another form of a line switch of the present invention
  • Pig. 3 shows a circuit diagram of a telephone subset incorporating a line switch of the present invention.
  • Pig. - shows a polarity guard incorporating the line switch.
  • a line switch circuit comprising output terminals 1 and 2 for connection to a telephone subset's line termi ⁇ nals via a polarity guard device (not shown) which ensures correct polarity irrespective of line polarity.
  • the circuit further comprises input termi ⁇ nals 3 and connected to the telephone subset's transmission circuit TX. Between terminals 1 and 3 is connected the collector/emitter path of a PNP transistor TR1 which is the main switching transistor. A resistor Rl is serially connected between terminal 1 and the collector element. The base element of transistor TR1 is coupled via resistor R2 to the collector ele ment of an NPN transistor TR3 which is the control transistor.
  • the emitter of transistor TR3 is connected to terminal 2 and the base element is cou ⁇ pled to control means (not shown) associated with transmission circuit TX.
  • the base element of TR3 is also connected to the collector element of an NPN transistor TR2 which is the protection transistor.
  • the base element of transistor TR2 is coupled to terminal 1 via resistor R3 and zener diode Zl.
  • the conductive path of transistor TR1 is in series with the loop circuit of telephone transmission circuit TX and may be controllably switched by con- trol transistor TR3 with signals applied to the latter transistor base ele ⁇ ment by the control means.
  • Over current protection for elements of the transmission circuit TX is provided by resistor Rl, typically 4.7 ohms, and diodes Dl and D2.
  • Diode D2 compensates the emitter/base voltage drop of transistor TR1 so that the voltage drop across resistor Rl is equal to the voltage drop across diode Dl.
  • the base current of transistor TR1 is reduced, causing the conductance of the emitter/collector junction to decrease thereby limiting the loop current.
  • Over voltage pro ⁇ tection for the main switching transistor TR1 is provided by protection transistor TR2. Should the voltage across terminals 1 and 2 rise above a predetermined level typically 150V, zener diode Zl begins to conduct and switches on transistor TR2 which in turn switches off control transistor TR3 and consequently transistor TR1. Transistor TR1 is thereby prevented from operating outside its safe operating area (SOA) .
  • SOA safe operating area
  • the line switch comprises a main switching tran ⁇ sistor arrangement consisting of a complementary pair of transistors TR1 and TR4 whose switching is controlled by a control transistor TR3.
  • the line switch includes overcurrent protection elements identical to those shown in Pig. 1, but omits the over voltage protection elements.
  • Such a line switch may be used where overvoltage protection is provided by a clamping device across terminals LI and L2, or where a suitable high volt ⁇ age transistor is used for transistor TR1, such as, for example a high- voltage DMOS device, or a high voltage bipolar device.
  • the telephone subset circuit comprises line terminals LI and L2 connected across the AC points of a polarity guard de ⁇ vice in the form of a diode bridge PG comprising diodes D3, D4, D5 and D6; It will be understood, however, that transistors, particularly field effect transistors, could substitute some or all of the diodes in the bridge, in which case it would be necessary to incorporate a polarity sensing control means.
  • a tone ringer (not shown) is also connected across the line termi ⁇ nals.
  • Across the DC points of bridge PG is a telephone transmission cir ⁇ cuit TX having a load impedance resistor R6.
  • a conventional ten number repetory tone/pulse dialler chip such as for exam ⁇ ple, a SHARP LR4806 designated RD, although a microprocessor could be uti ⁇ lized.
  • Dialler RD includes a dial pulse output A, a mute signal output B, a power terminal C, common voltage rail terminal D, dual tone multifre- quency (DTMP) output E, an earth recall/ground star output P, a DC charac ⁇ teristic adjustment signal or "kick-start" output G, a plurality of inputs 1-28 from the key-pad (not shown) associated with the subset, and inputs X and Y from the associated hook-switch HS. Also connected across the DC points of bridge PG and in parallel with repetory dialler RD is a storage capacitor Cl which provides power for repetory dialler RD during decadic dialling. A current bleed path is provided by resistor R2 and diode D7 connected between the DC positive point of the polarity guard PG and output C of dialler RD to provide power for the dialler when the subset is in the- on-hook mode.
  • DTMP dual tone multifre- quency
  • E earth recall/ground star output
  • P DC
  • a shunt circuit for "kick start" comprising a main switch in the form of a complementary configuration of transistors TR7 and TR8, and a control tran ⁇ sistor TR9 whose control element is connected to output G of dialler RD.
  • the shunt circuit Viewed from the line terminals Ll and L2, the shunt circuit is connected behind the line switch and before the transmission circuit TX. It will be understood, however, that the shunt circuit can be connected across the loop between the polarity guard PG and the line switch.
  • the main switching path of the earth recall/ground start switching circuit comprising a main switch in the form of a complementary configuration of transistors TR4 and TR5, and a control transistor TR6 whose base element is connected to output P of dialler RD.
  • a mute signal is applied to output B which mutes the transmission circuit TX; a signal Is applied to output G which turns on the control transistor TR9 of the shunt circuit which in turn switches on transistors TR8 and TR7; and a signal is applied to output A which turns on the control transistor TR3 of the line switch which In turn switches on transistors TR2 and TR1.
  • a current loop is provided via line terminal Ll, positive point of polarity guard PG, resistor Rl, collector/emitter junction of transistor TR1, collector/emitter junction of the shunt circuit transistor TR7, negative point of polarity guard PG to L2.
  • the shunt circuit which effectively shunts the transmission circuit TX reduces the voltage drop of the loop circuit thereby providing a higher loop current to ensure exchange line relay operation on long line conditions.
  • the signal applied to output G of dialler RD is changed and control transistor TR9 of the shunt circuit is switched off which in turn switches off transistor TR8 and transistor TR7 whereupon the shunt circuit is removed and transmission circuit TX substitutes the shunt circuit in the current loop.
  • the signal applied to output B of dialler RD is changed and the muting is removed from the transmission circuit TX.
  • TLB timed loop break
  • dialler RD If the dialler RD has been set in the DTMF mode, signals from the keypad cause dialler RD to generate a coded VF signal representing the dig ⁇ its keyed.
  • the coded VF signal is applied to output E of dialler RD which is coupled to the line terminals Ll and L2 by a current source means (not shown) In the transmission circuit TX. 7
  • the recall system associated with the exchange line equipment is ⁇ ___.
  • earth recall system upon actuation of a designated recall key its opera ⁇ tion is sensed by dialler RD which thereupon applies a signal to output P for at least 100 m/s.
  • This signal switches on the control transistor TR6 of the earth recall/ground stand switching circuit, which in turn switches on transistors TR5 and TR4.
  • Earth extended from the positive pole of the exchange battery to terminal E is thereby connected via the collector/emitter junction of transistor TR4 to the negative point of po ⁇ larity guard PG and line terminal L2, and is sensed by the exchange equip- ment, whereupon the exchange equipment is prepared for further dialling signals.
  • a timed loop break as described above will also be applied during earth recall. Under certain circumstances the additional TLB signal actu ⁇ ally assists the earth recall operation.
  • ground start is required to sieze the ex ⁇ change equipment prior to dialling. This is accomplished by momentarily applying an earth, extended from the earthed pole of the exchange battery, to a line terminal having the opposite pole potential, thereby unbalancing the line.
  • the ground start sig ⁇ nal may be provided in a manner similar to the provision of the earth re- call described above with a key designated for earth start.
  • the dialler RD could be programed to provide the earth start signal at output P upon closing the contacts of the hook switch.
  • Fig. 4 shows an embodiment of the line switch incorporating the polar ⁇ ity guard function.
  • This arrangement is similar to a bridge diode in which one diode in each DC circuit has been replaced by a controllable switch (5,6) each of which may perform any or all of the functions previously de-- scribed.
  • the output of the bridge is fed to terminals 3 and 4 across which is a polarity sensing circuit which switches the switches 5 and 6 on and off such that when terminal 1 is positive switch 5 is on and 6 is off and conversely if 2 is positive 6 is on and 5 is off.
  • the polarity guard may Incorporate a time delay to allow fleeting test reversals of the line volt ⁇ age by the exchange test and supervisory equipment.
  • An additional terminal 10 is provided to give the desired telephone signalling controls. This may be done through polarity sensor 9 as shown or by further connections to switches 5 ad 6, not shown.
  • diodes 7 and 8 may be replaced by further switches and controlled so the switch replacing 7 is switched synchronously with 6, and 5 with 8.
  • Polarity sensor 9 may be applied across the output of the bridge as an alternative arrangement.
  • An arrangement such as shown in Pig. 4 may be used to replace the bridge rectifier of Pig. 3.
  • the afore described invention may be advantageously applied in the manufacture of telephone subset apparatus.

Landscapes

  • Engineering & Computer Science (AREA)
  • Signal Processing (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Interface Circuits In Exchanges (AREA)

Abstract

Un commutateur de lignes de postes de téléphone d'abonnés (Fig. 1) comprend un dispositif de bornes d'entrée (3, 4) de couplage aux bornes de ligne du circuit du poste d'abonné et un dispositif de bornes de sortie (1, 2) pour connexion au circuit de transmission du circuit du poste d'abonné. Un premier dispositif commutateur (TR 1) à semi-conducteurs comprend un trajet conducteur réglable connecté en série entre une première borne (3) du dispositif de bornes d'entrée et une première sortie (1) du dispositif de bornes de sortie. Un deuxième dispositif semi-conducteurs (TR 3) comprend un trajet conducteur réglable connecté entre l'élément de réglage du premier commutateur à semi-conducteurs (TR 1) et une deuxième borne (4) du dispositif de bornes d'entrée, la deuxième borne d'entrée et la deuxième borne de sortie étant branchées ensemble. L'élément de réglage forme une première entrée de réglage du couplage à un dispositif de commande associé au circuit de transmission afin d'effectuer de manière réglable la commutation du courant de circuit du poste de téléphone d'abonné.
PCT/AU1986/000182 1985-07-18 1986-07-07 Commutateur de lignes telephoniques WO1987000717A1 (fr)

Priority Applications (6)

Application Number Priority Date Filing Date Title
DE3689653T DE3689653T2 (de) 1985-07-18 1986-07-07 Schalter für fernsprecherlinie.
KR1019870700234A KR940011757B1 (ko) 1985-07-18 1986-07-07 전화 라인 스위치
JP61503791A JPH0795773B2 (ja) 1985-07-18 1986-07-07 電話機ラインスイッチ
BR8606792A BR8606792A (pt) 1985-07-18 1986-07-07 Comutador de linha telefonica
GB8705311A GB2187363B (en) 1985-07-18 1986-07-07 A telephone line switch
AT86904037T ATE101773T1 (de) 1985-07-18 1986-07-07 Schalter fuer fernsprecherlinie.

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
AUPH1533 1985-07-18
AUPH153385 1985-07-18
AU59803/86A AU580679B2 (en) 1985-07-18 1986-07-07 A telephone line switch

Publications (1)

Publication Number Publication Date
WO1987000717A1 true WO1987000717A1 (fr) 1987-01-29

Family

ID=25632594

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/AU1986/000182 WO1987000717A1 (fr) 1985-07-18 1986-07-07 Commutateur de lignes telephoniques

Country Status (1)

Country Link
WO (1) WO1987000717A1 (fr)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0254405A2 (fr) * 1986-07-14 1988-01-27 Siliconix Limited Appareil téléphonique
WO1988008234A1 (fr) * 1987-04-09 1988-10-20 Standard Telephones And Cables Pty. Ltd. Ensemble de circuits telephoniques d'abonne
WO1990007835A1 (fr) * 1988-12-23 1990-07-12 Standard Telephones And Cables Pty. Limited Agencement de poste telephonique d'abonne
FR2655500A1 (fr) * 1989-12-01 1991-06-07 Horlogerie Photograph Fse Interface d'entree electronique de poste telephonique.
EP0535352A1 (fr) * 1991-09-04 1993-04-07 Alcatel Australia Limited Circuit de commande pour le commutateur de ligne d'un poste téléphonique
EP0593115A2 (fr) * 1992-10-14 1994-04-20 N.V. Philips' Gloeilampenfabrieken Commutateur à crochet électronique pour un poste téléphonique

Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2774888A (en) * 1955-08-23 1956-12-18 Gen Dynamics Corp Electronic switch
US2876366A (en) * 1953-12-28 1959-03-03 Bell Telephone Labor Inc Semiconductor switching devices
GB839567A (en) * 1956-10-24 1960-06-29 Automatic Telephone & Elect Improvements in or relating to telephone systems
US2972683A (en) * 1957-07-24 1961-02-21 Bell Telephone Labor Inc Electrical circuits for communication networks
US4163159A (en) * 1976-12-18 1979-07-31 Licentia Patent-Verwaltungs G.M.B.H. Attenuation-free electronic switch
EP0009293A1 (fr) * 1978-09-21 1980-04-02 Staat der Nederlanden (Staatsbedrijf der Posterijen, Telegrafie en Telefonie) Circuit pour connecter un seul à la fois d'un nombre de postes téléphoniques à une ligne d'abonné
GB1574078A (en) * 1976-12-01 1980-09-03 Telefonbau & Normalzeit Gmbh Voltage-limiting circuit
US4341991A (en) * 1979-10-01 1982-07-27 U.S. Philips Corporation Voltage stabilizer suitable for a telephone set
US4388499A (en) * 1980-02-26 1983-06-14 U.S. Philips Corporation Line interruption circuit for use in a telephone set
US4390753A (en) * 1980-02-26 1983-06-28 U.S. Philips Corporation Line interruption arrangement

Patent Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2876366A (en) * 1953-12-28 1959-03-03 Bell Telephone Labor Inc Semiconductor switching devices
US2774888A (en) * 1955-08-23 1956-12-18 Gen Dynamics Corp Electronic switch
GB839567A (en) * 1956-10-24 1960-06-29 Automatic Telephone & Elect Improvements in or relating to telephone systems
US2972683A (en) * 1957-07-24 1961-02-21 Bell Telephone Labor Inc Electrical circuits for communication networks
GB1574078A (en) * 1976-12-01 1980-09-03 Telefonbau & Normalzeit Gmbh Voltage-limiting circuit
US4163159A (en) * 1976-12-18 1979-07-31 Licentia Patent-Verwaltungs G.M.B.H. Attenuation-free electronic switch
EP0009293A1 (fr) * 1978-09-21 1980-04-02 Staat der Nederlanden (Staatsbedrijf der Posterijen, Telegrafie en Telefonie) Circuit pour connecter un seul à la fois d'un nombre de postes téléphoniques à une ligne d'abonné
US4341991A (en) * 1979-10-01 1982-07-27 U.S. Philips Corporation Voltage stabilizer suitable for a telephone set
US4388499A (en) * 1980-02-26 1983-06-14 U.S. Philips Corporation Line interruption circuit for use in a telephone set
US4390753A (en) * 1980-02-26 1983-06-28 U.S. Philips Corporation Line interruption arrangement

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See also references of EP0233892A4 *

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0254405A2 (fr) * 1986-07-14 1988-01-27 Siliconix Limited Appareil téléphonique
EP0254405A3 (en) * 1986-07-14 1989-04-26 Siliconix Limited Telephone instrument
US4887295A (en) * 1986-07-14 1989-12-12 Siliconix Limited Telephone instrument
WO1988008234A1 (fr) * 1987-04-09 1988-10-20 Standard Telephones And Cables Pty. Ltd. Ensemble de circuits telephoniques d'abonne
WO1990007835A1 (fr) * 1988-12-23 1990-07-12 Standard Telephones And Cables Pty. Limited Agencement de poste telephonique d'abonne
US5317634A (en) * 1988-12-23 1994-05-31 Alcatel N.V. Telephone subset arrangement
FR2655500A1 (fr) * 1989-12-01 1991-06-07 Horlogerie Photograph Fse Interface d'entree electronique de poste telephonique.
EP0436445A1 (fr) * 1989-12-01 1991-07-10 HORLOGERIE PHOTOGRAPHIQUE FRANCAISE (société anonyme) Interface d'entrée électronique de poste télephonique
EP0535352A1 (fr) * 1991-09-04 1993-04-07 Alcatel Australia Limited Circuit de commande pour le commutateur de ligne d'un poste téléphonique
US5384837A (en) * 1991-09-04 1995-01-24 Alcatel Australia Limited Line switch control circuit arrangement for telephone subset
EP0593115A2 (fr) * 1992-10-14 1994-04-20 N.V. Philips' Gloeilampenfabrieken Commutateur à crochet électronique pour un poste téléphonique
EP0593115A3 (fr) * 1992-10-14 1999-02-17 Koninklijke Philips Electronics N.V. Commutateur à crochet électronique pour un poste téléphonique

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