DE1222990B - Circuit arrangement for company lines in telecommunications, in particular telephone systems - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Int. Cl .:

H04m

German class: 21 a3 - 53/01

Number:
File number:
Registration date:
Display day:

S 81451 VIII a / 21 a3
September 14, 1962
August 18, 1966

The invention relates to a circuit arrangement for company lines in telecommunications, in particular Telephone systems. It relates in particular to such arrangements in which the individual Subscriber stations connected to a common main line via individual branch lines and in which rectifiers are inserted in these branch lines, depending on the sign the voltage applied to the common main line in the exchange into the pass-through or Restricted area can be controlled.

Company managements generally want individual fee recording in office. In known arrangements, the connection of the respective billing meter is either by the automatic transmission of characters identifying the calling subscriber - for example a damped oscillation of a certain frequency initiated by the hook switch - initiated or by dialing a code number assigned to the individual subscribers (e.g. a Part of your own phone number). The first-mentioned process is very complex, the other, however unreliable, as the calling party has intentionally or unintentionally chosen a wrong one Code number can debit the billing meter of another participant.

A method has now become known to force the specification of the correct call identifier. This is done by the fact that the subscriber must give his own call identifier in order to to unblock his communication channel. The invention provides a special solution to this problem, namely to force the subscriber to provide his correct subscriber address. This solution is in the case of company lines, whose subscriber units have individual branch lines into which the secret traffic Serving rectifiers are inserted, are in communication with the common main line and in the case of outgoing traffic via the common main line to the exchange to be transmitted current impulse series serve as dialing indicators, while in the incoming traffic the individual subscriber stations are selected by individual identification frequency, thereby characterized in that said rectifiers are forward-biased when the main line is free and thus permit the transmission of dialing codes in the form of series of current impulses, blocked by potential reversal on the main line after selecting a number of series of current impulses and that these series of current impulses in the

Circuit arrangement for company lines
in telecommunications, in particular telephone systems

Applicant:

Siemens & Halske Aktiengesellschaft,

Berlin and Munich,

Munich 2, Witteisbacherplatz 2

Named as inventor:

Dipl.-Ing. Richard Grote, Munich

implementation point in a marking frequency that is applied to the main line and

ao the effective connection of the calling subscriber station with this main line if and only if it matches its subscriber address.

In the drawings, an embodiment of the invention is shown. It is about a Company management, in which individual identification frequencies are assigned to the individual subscriber stations are.

Fi g. 1 represents one of the subscriber stations;

Fig. 2 gives a schematic representation of the Company management transfer, hereinafter referred to as transfer for short, again.

Each subscriber station contains a selective receiver, the sieve means on the individual Identifying frequency are matched and the AC voltage signals of this frequency in switching functions implements. With reference to FIG. 1, the mode of operation of this receiver will first be described in more detail.

A high-pass F1 separates the audio frequency voltage from the simultaneously arriving ringing voltage. This high pass is the same for all participants. Its cutoff frequency is determined by the lowest identification frequency used.

An audio frequency α to the cores and lying b passes through the high-pass filter Fl to the transistor Trl. A corresponding current flows through the base-emitter paths of the two cascade-connected transistors to the input of the filter F 2. This filter is a bandpass filter in the pass band of which the identification frequency to be received is located. For alternating currents of this frequency

609 610/77

3 4

so the input resistance of the filter is high and in the circuit shown he gives z. B. by

its operational damping Idein. You get unrestricted- the choice of the number 2 his desire for her-

Switch to the filter output and load a printout via the equalization of an external connection. Above

richterG3 the capacitor C 4 on. Through the condensate arm dl of the rotary magnet DMl

capacitor voltage, the transistors in the 5 controlled selector, a relay EX is energized, which with

Pass band controlled and cause the other contact lex to start the call seeker AS

train of the receiving relay B. The dimensioning of C 4 causes.

is decisive for the response time of the receiver. The calling subscriber has the second digit

You must be chosen so large that the relay B ordinal number of its own connection within

due to background noises or speech vibrations, the OK of the company management to choose. The corresponding

The number of oscillations of the series of impulses is randomly assigned to the rotary magnet DM2 for a short time.

Receivers have assigned identification frequency leads. The associated voter arm d21 arises

can not get excited. to the identity assigned to the calling subscriber

The frequency of the incoming alternation frequency is included. A second arm d 22 of the same

Current signal outside the pass band of 15 selector switches the charge meter Z of the calling party

Filter F 2, the following conditions arise: Participant to the wire zi, via which the counting pulses

The alternating current signal is amplified at the winding.

treatment I of the relay B, because the now low current impulse series located in the emitter circuit during the second digit corresponding to the transistor Tr 2 becomes a relay via the arm d 02 of the selector, which does not belong to the input resistance of the filter F 2 Q values negative feedback. The amplified signal excites that with its contact 2 q the connection voltage is transformed to the winding II of the relay B of the identification sought by the arm d21 , rectified by the rectifier G 2 to the winding frequency of the calling subscriber, charges the capacitor C. 3 on and controls treatment II of the line transformer LT prepared. This causes the transistors in the blocking range, so 25 connection takes place at the end of the second current that the relay B can not respond. shock series through the contact 3 ν 1 and is during

Let us now consider the overall effect of the third series of current impulses through a contact 2 r

circuit for the various types of traffic be maintained by the relay R , as well as that

seeks. Relay Q is energized via the selector arm dO2 . One

To establish an outgoing connection 30 of the identification frequency of the calling subscriber, the subscriber picks up his handset. By means of the corresponding alternating voltage reaches the suffering contact 2u of the hook-and-loop switch, a line cores α and b and causes the circuit above to be closed, in the manner established by the discharge in the station of the calling part of the capacitor C 5, the relay A via the bridge receiver the pick-up of the audio frequency receiving relay B. rectifier GS is excited. It creates through 35, this creates with his contact 4 b to hold a contact la the latch circle

1. Earth (transmission), / 1 (Π), 2χ, b-wire, GS, 3. + (0B), 5 (1), 4b, 4a, 3 κ, - (0B).

A (l), lu, T2 (l), R2, nsi, lb, la, G6, a-wire, ·· »♦., R. , · _N ,, _{f tU1} . ,

1 ν ffrhprtraormtA 7ΊίΤ> - Furthermore, the relay B opens the contact 1 b and

ix ^ uoenragung ,, x _W,. ^ _sd j _{ßn the contact 2Ö} This is the current

So that the relay ^ is disconnected during the now following circle 1, and takes its place

Digit dialing by opening the raiz contact not circuit

falls during this time by a nsa- _{4 ß} _ _{Ad 2b mi} R} 2, T2 (V, lu, G5, A (l),

Contact eme retaining coil .4 (11) over & -wire

2. - (0B), A (Il), lnsa, 3b, Γ2 (Π), 3u, + (0B) * ⁵ . _J '' _J _,. _Λ

in which, among other things, relay A continued

excited. will.

The low-resistance subscriber loop in the current The third series of current impulses is passed on via the contact circuit 1, the voltage between the wires α 3 r and the call seeker AS . At the end and b of the company line to a value from 50 this series of current impulses, when the relay Vl drops out, which is so low that the charge of the con is through its contact 2 vl in one through the capacitors C 5 in the rest Subscriber stations not contact 1 q prepared circuit a relay X is more sufficient to energize the associated relay A effectively, which holds itself with its own contact Sx , to excite. A flag SZ shows the »busy - via its contact 3 χ the fourth state« of the line in the subscriber stations. 55 chose the corresponding digit and all others

In circuit 1, the pulse relay / 1 series of current impulses is also emitted.

the transmission excited. About his contact IzI is also through two further contacts

an occupancy relay Cl is switched on, its- Ix and 2x the voltage of the central battery on the

on the other hand with IcI a response circuit for the line reversed. As a result, the rectifier

Rotary solenoids DMO 'prepared for a selector. These 60 terG6 in the subscriber stations according to the invention in

This voter makes reversed because of the drop-out delay from the lock state.

Vl only one step with each series of impulses and the first participant wants an internal connection

switches to build up the torque via his arm dOl , he has to select a 3 as the first digit.

DM1, DM2 and DM3 of three other voters. As a result, a relay JN is activated via the voter arm dl

a contact 2 il of the pulse relay / 1. 65 effective, the call signal with its contact Hn

The calling subscriber has to make the decision between the external identification frequency of the called subscriber and the internal connection by selecting and with his contact 2 in the connection of the first digit. prepares. The participant selects how as the second digit

its own ordinal number when the external connection is set up and thus sets the selector arm d21 back to the identification frequency assigned to it. Then he dials the number (or code) of the called subscriber. The third series of impulses corresponding to this selection is fed to the rotary magnet DM3. The associated voter arm d 31 adjusts itself to the identification frequency of the called subscriber. After dialing the third digit, the relay X is switched on as described above. By reversing the polarity of the central battery on the line, this controls, among other things, the rectifier G 6 in the station of the calling subscriber to the blocking state and thereby interrupts the low-resistance subscriber loop in circuit 1. The pulse relay 71 drops out and switches the identification frequency of the with its break contact 6/1 called subscriber via contacts d31, 6/1, 4x,

2 in to winding II of the line transformer LT. Furthermore, the call relay K is via the contacts 5x, ao

3 i 1.1 in on the timer 3 ″ for the call signal. The contact 1 k switches on the call signal machine RSM . A second contact 2 k of the relay switches on a relay M , which is held by its contact Im

5. Earth, 4/1, 3in, Im, M, -.

An alternating voltage with the identification frequency of the called subscriber corresponding to the number of vibrations reaches the cores α and b of the company line via the line transformer LT and brings the receiving relay B in the station of the called subscriber to the address in the manner described above. The alarm clock W is switched on via contact 2 &.

If the called subscriber picks up his handset, the low-resistance loop of circuit 4 is created, in which relay A , among other things, is excited.

In the transmission, the pulse relay / 1 picks up again and interrupts the circuit of the call relay K with contact 3 zl.

4 x, 2 in to the line transformer LT (II). The relay M has a drop-out delay and keeps its contact closed for 2 m long enough to enable the relay B to pick up in the station of the calling subscriber. The internal connection is now established.

With incoming traffic, the line selector LW is brought into the position corresponding to the number of the called subscriber. An occupancy relay C 2 is excited via the d-Aim , which with its contact Ic2 switches on a relay interrupter circuit consisting of the two windings I and II of the relay / 2. The rotary magnet DM 3 is excited via contact 3/2. The associated selector arm d32 starts to move and uses relay P to check the setting of the line selector LW. Meanwhile, a second voter arm d31 searches for the identification frequency of the called subscriber. When the test relay P responds, this frequency is passed on to the line transformer LT via contact 3 p. The relay B in the station of the called subscriber is activated in the manner described above. At the same time, contact 2 p of test relay P switches on call relay K.

Improper use of the system could also result from the fact that the subscriber, after picking up the handset, switches on relay B in his own connection via the circuit created by the attraction of A , by means of an acoustic tone of the respective identification frequency, for example from a whistle hits the microphone, a corresponding alternating current from this reaches the input of the high-pass filter F1 via the transformer T 2 and thus to the selective receiver. According to a further embodiment of the invention, this is prevented in that the winding II of the transformer T 2 is short-circuited by a normally closed contact 3 b of the relay B in this switching state.

If a subscriber finds company management occupied when the handset is picked up, relay A cannot respond to its connection for the reasons mentioned earlier. He recognizes the occupied state by a flag SZ, which is switched on by the hook switch contact 3 u via the break contact 3 α. In this case, however, he must be given the opportunity to send urgent emergency calls. For this purpose, a button with contacts 1Γ and 2 Γ is provided in the subscriber connections. An alternating current connection between the microphone transmitter and the company line is established via 1Γ through the capacitor C 2. The subscriber can speak into the existing connection and request the other subscribers to release the line for an emergency call. At the same time, contact 2 Γ of the button prevents eavesdropping on the call being made via the existing connection by short-circuiting receiver F.

Claims (4)

Patent claims: 1. Circuit arrangement for telecommunications, in particular telephone systems with company lines, in which the participants, their subscriber stations Via individual branch lines into the rectifiers serving the secret traffic are inserted, are in connection with the common main line when building a outgoing connection should be forced to specify their subscriber address which also in outgoing traffic via the common main line to the exchange to be transmitted current impulse series serve as dialing indicators, while in the incoming traffic the individual subscriber locations selected by individual identification frequencies are, characterized in that the said rectifiers, when the main line is free are biased in the forward direction and thus a transmission of dialing numbers in the form of impulse series, at the choice of a number of current impulse series are blocked by potential reversal on the main line and that these current impulse series in the switching center to be converted into an identification frequency that is sent to the main line is created and the effective connection of the calling subscriber station with this Main line then and only if it matches its subscriber address. 2. Circuit arrangement according to claim 1 for systems with receiving devices for converting Conversion of audio frequency signals into switching functions with controllable non-linear elements, the working state of which is controlled by the frequency of the input voltage in such a way that they only carry significant current in a narrow frequency range, characterized in that the control feeds back into the current-permeable state via a bandpass filter (F 2) and the control in the blocking state takes place via a transformer (B) and that the frequency-dependent input resistance of the bandpass filter (F 2) is placed in a negative feedback branch. 3. Circuit arrangement according to claim 2, characterized in that the transformer is formed by two windings (I, II) of a relay (B) . 4. Circuit arrangement according to one of the preceding claims, characterized in that the microphone (M) of the subscriber station is short-circuited by a contact (3 b) of the audio frequency receiver for alternating current. Considered publications:
German patent specifications No. 804 690, 886 020. 1 sheet of drawings 609 610/77 8.66 © Bundesdruckerei Berlin