DE1239367B - Circuit arrangement for subscriber identification in telephone switching systems - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY GERMAN 4057IW PATENT OFFICE Int. Cl .:

H04m

EDITORIAL

H04q
German class: 21 a3 - 59/20

Number: 1 239 367

File number: E 26268 VIII a / 21 a3

Filing date: January 22, 1964

Open date: April 27, 1967

The invention relates to a circuit arrangement for subscriber identification in telephone switching systems with a generator for generating the call number or connection number of a subscriber, consisting of from a ring core evaluation field or translator, which has a group of magnetic ring cores, which correspond to each digit of the subscriber's phone number, from one for each subscriber separate translator line or evaluation loop, which in each group by one or more of the Cores are looped, which represent the value of the digit of a digit in the subscriber number, which corresponds to the group, and from a separate output winding for each core.

In a known arrangement of this type, the evaluation loops are continuously over the subscriber line closed, making the required crosstalk attenuation and signal to noise ratio a problem (German Auslegeschrift 1102 827).

In addition, a circuit arrangement has become known (German patent specification 701 244) at a normally charged capacitor as a pulse current source for a basic identification signal is used. In this arrangement, this seeks to interrupt the rotation of a selector Serving test relays do not have a test potential in an identification multiple. Rather, it becomes the voter advanced until a special circuit for the corresponding test relay is closed. In contrast to this, the basic identification signal is used in the circuit arrangement according to the invention used directly to perform switching operations.

The object of the subject matter of the invention is to provide a basic identification signal that can be used for switching without the problems of crosstalk attenuation and signal-to-noise ratio.

According to the invention, this object is achieved in that there is a capacity for each participant who is represented by a translator manager, is present separately, and by a switch which responds to the call of a subscriber and causes a displacement current in the capacity and flows in the translator ladder as a basic signal.

According to a further development of the invention, the capacitor is normally charged, and the basic signal is triggered by the discharging of the capacitor when the subscriber line relay is in operation. This achieves a pulse that is large enough for switching magnetic ring cores and, as long as the above-mentioned switch is closed, the circuit arrangement can be used
Participant identification in
Telephone exchanges

Applicant:

Ericsson Telephones Limited, London

Representative:

Dr. B. Quarder, patent attorney,
Stuttgart, Richard-Wagner-Str. 16

Named as inventor:
George Arthur Matthews,
Nottingham (Great Britain)

Claimed priority:

Great Britain 7 February 1963 (5112)

is to charge the capacitor with a small charging current.

The basic signal is used twice if the translator has an additional core through which all translator conductors are looped, and if this core has an output winding having an output or Supplies start signal. A start signal can thus be derived from the basic signal.

The signals occurring at the output windings of the magnetic ring cores of the translator can be can be used in any way. The invention can be used for any switching center can be used, for example for an electromechanical or a so-called electronic one System.

The invention is explained with reference to the drawings.

F i g. 1 shows a known toroidal core evaluation field, called a translator, for three-digit call numbers and one of the possibilities for utilizing the output signals of the magnetic ring cores of the translator;

F i g. 2 shows a circuit arrangement according to the invention for generating a basic signal.

The in F i g. 1 illustrated translator has thirty arranged in three lines of ten pieces, in the following magnetic ring cores called cores. Each line corresponds to one digit of the phone number; the cores C10 to C19 thus represent the digits 0

709 577/62

to 9 of the first digit, etc. Each core is used as a transmitter. Input terminals 10 are provided, the number of which corresponds to the number of subscribers supplied with the aid of the translator. A translator conductor can be connected to each of these terminals, of which only two, namely conductors 11 and 12 , are shown for the sake of clarity. Each of these conductors is looped through a core of each row and thus gives the number of the caller to which it is assigned. The conductor III is looped through the cores CIl, C 20 and C 32 and results in the call number 102. The other end of each translator head is connected to a terminal 13 of a further set of terminals. The terminals 10 and 13 are connected so that when a subscriber lifts the handset and the hook switch is released, a short-circuit pulse flows through the corresponding translator conductor. Each of the thirty cores has an output winding which is connected to the input of a separate translator amplifier TA.

The memory matrix consists of three separate memories, each of which has three sets of ten cores with a rectangular hysteresis loop and each of which can store a three-digit telephone number. The cores assigned to a memory are shown arranged in a column in the drawing. Four wires are looped through each core. The output of each translator amplifier is routed onto an input wire that is looped through corresponding cores of each memory. In the same way, a common output wire is used for corresponding cores of each memory and is connected to the input of a separate memory amplifier SA . A common write wire coming from an input control device / PC is looped through all the cores of a memory. In addition, a common read wire from a read control device ROC is looped through all memories.

The input control device is controlled by a »Start« core CS. This core forms part of the translator and every translator manager is looped through it. It is a core of the transformer type.

The writing in any core of the memory matrix is effected in a known manner with the aid of coincident half-current pulses, a half-current pulse generating half the magnetic flux which is required to switch a core. A core is switched by the simultaneous occurrence of a pulse from the input control device IPC and a pulse from the associated translator amplifier TA. A "reading" of a core, however, is effected by the application of a full current pulse by the reading controller ROC , that is, a pulse which generates sufficient magnetic flux to switch a core.

The output of each memory amplifier SA can be connected via suitable switches to any register RG , two of which are shown. An access control arrangement ACE controls the connection of the register RG to the outputs of the memory amplifier SA.

The system works as follows:

The current flow occurring on a subscriber line after the fork switch has been released causes a ringer relay operating cycle L in FIG. 2, thereby indirectly a current pulse to the booster conductor of that subscriber, for example the conductor 12 in Fig. 1. This conductor is looped through the "Start" core SC and through the cores C 12, C 29 and C 32, a telephone number 292 correspond. The current pulse on the translator conductor induces a pulse in the output windings of these four cores and thus supplies an input signal to the four assigned amplifiers. The output of the "Start" amplifier A supplies a trigger pulse to the input control device IPC and causes a current pulse to be passed on through the cores of the first memory. At the same time, pulses are passed over three input wires, and the cores SC 112, SC 129 and 5C132 are switched by the simultaneously occurring pulses. The pulse of the input control device IPC also reaches the reading control device ROC and there indicates that a number has been stored in the first memory of the matrix. The input control device IPC is then prepared to store the next number generated by the translator. Thus, the memories are used one after the other, and the signals reaching the reading control device ROC indicate which of the memories is being used.

As explained below, the connection of the registers RG to the memory outputs is controlled by the access control arrangement ACE. Normally a register is switched so that it is ready to receive any number read from memory. On the other hand, the access control arrangement ACE can be switched in such a way that it only connects a register to the memory outputs when a number is entered into a memory. When a number is to be transferred from a memory to a register, the access control arrangement ACE, after it has determined that there is a connection to a register, causes the reading control device ROC to transmit a full-flow reading pulse to the memory through the cores of the associated memory looped wire. The resulting output signals from the memory cores reach the register via the memory amplifier SA. The register is then switched off. The reading control device ROC is then switched on by the access control arrangement ACE and thus prepared for reading a further memory.

It emerges from the above that the devices IPC and ROC can be switched on and operated quite independently of one another as long as the reading control device ROC always lags behind the input control device IPC.

In the present specification, the term "looped through a core" means that a Head is guided in the axial direction through a magnetic core, but could also mean that this Conductor or wire forms a coil or winding on each core. Looping through is practical of the wire in the limited sense of the word advantageous, since this way the translator wires are very can simply be introduced into and removed from a translator, which in the event of a change in the Call number may be required.

The cores in the translator and in the memory matrix also do not need to be in rows and columns to be arranged as shown in the drawing

represents is. In addition, of course, the number does not have to be limited to three digits. Any number of memories and registers can be provided.

Any type of switch can be used as register access switch, mechanical or electronic.

In certain cases the translator or storage amplifiers TA or SA are not required. Their absence does not affect the operation of the circuit arrangement according to the invention.

As mentioned above, the translator works with a decimal code. In other exemplary embodiments of the circuit arrangement designed according to the invention other codes can be used; for example, the translator cores can be arranged so that they the call number in a Generate "two-out-of-five" code. This can be done in a number of ways known to one of ordinary skill in the art Because of being executed. so

As shown in FIG. 2, a capacitor Q is provided for each telephone line in accordance with the invention. One plate of this capacitor Q is connected to the associated terminal 10 of the translator, from which the translator conductor runs to the corresponding terminal 13, which is connected to earth via a current limiting resistor (not shown). The other plate is connected to a grounded battery via resistors Rl, Rl. A normally open contact L of the usual subscriber line relay or call relay is placed between earth and the junction of the resistors R1, R2 . The other plate of the capacitor Q is connected via a normally closed contact K of the usual subscriber cut-off relay or isolating relay to the normally open contact L , which is normally open, so that the capacitor Q is normally charged.

When the subscriber picks up his receiver, the normally open contact L closes, and the capacitor β discharges directly to earth via the normally closed contact K , thereby causing a relatively large discharge current in the translator line connected to terminal 10. This current is the basic signal. The isolating relay then responds in the normal way and opens the normally closed contact K. At the end of the conversation, the contacts L and K return to their starting position, and the capacitor Q is slowly charged again via the series-connected resistors R 1 and R2 , and the charging current is therefore correspondingly low.

If, after generating a call, a subscriber starts dialing before he hears the exchange signal, the normally open contact L will open and close, while the normally closed contact if remains closed. Each time the normally open contact L is opened , the capacitor Q begins to charge via the resistor R 2 and the normally closed contact K , and the charging current and the extent of charging are relatively low. Each time the normally open contact L is closed, the small amount of stored charge is discharged to earth via the contacts L, K , and the discharge current is again relatively low, since the discharged charge is relatively small.

When a call arrives at the subscriber, the isolating relay is activated first, followed by the call relay. The normally closed contact K opens first and is followed by the closing of the normally open contact L. The capacitor Q then discharges via the resistor R 1 and the normally open contact L, the discharge current again being relatively small. The values for the resistors R 1 and R 2 are chosen so that the output signal arising at the output winding of a translator core as a result of the relatively low charging or discharging currents cannot erroneously actuate any part of the device to which the output windings are connected.

Modifications of the circuit arrangement designed according to the invention are possible. For example, the capacitor Q can normally be discharged and the basic signal generated by the current that flows during the charging process.

Claims (3)

Patent claims: 1. Circuit arrangement for subscriber identification in telephone exchanges with a generator for generating the call or connection number of a subscriber, consisting of a ring core evaluation field or translator, which has a group of magnetic ring cores that correspond to each digit of the subscriber's call number, from a separate translator line for each subscriber or evaluation loop, which is looped in each group through one or more of the cores, which represent the value of the digit of a digit in the subscriber number that corresponds to the group, and from a separate output winding for each core, characterized by a capacitance (Q in Fi g. 2), which is available separately for each subscriber represented by a translator head, and by a switch (L) which responds to a subscriber's call and causes a shift current that is in the capacity and in the translator head as Basic signal flows. 2. System according to claim 1, characterized in that the capacitor (Q) is normally charged and that the basic signal is triggered by the discharging of the capacitor during operation of the subscriber line relay. 3. Installation according to claim 1 and / or 2, characterized in that the translator has an additional core (CS) through which all translator conductors are looped, and that this core has an output winding which has an output for each basic signal occurring on a translator conductor - or provides a start signal. Considered publications: German Patent No. 701244;
German explanatory documents No. 1001 335,
004 676.1102 827.1103 987.1110 246.1110 247. 1 sheet of drawings 709 577/62 4.67 © Bundesdruckerei Berlin