DE762436C - Circuit arrangement for telephone systems with main and sub-exchanges - Google Patents

Description

Circuit arrangement for telephone systems with main and sub-exchanges It is known that in telephone systems, especially in those with dialer operation, the relay and selector contacts switched on in the speech lines cause malfunctions tend, mostly temporarily, an understanding of the two speaking participants to make impossible. These disorders are generally not related to combustion or Contamination of the contacts can be attributed, but they arise from the fact that a very thin, non-conductive layer forms between the contact points, which interrupts the circuits.

It is known that these disorders primarily occur when the contacts are subjected to vibrations and it is further known that the disruption can for the most part be eliminated if care is taken to ensure that that the contacts are constantly or temporarily from a direct or alternating current are flowed through, the voltage of which is at least i volts.

These disturbances are particularly unpleasant when in the connection amplifier devices are switched on, for their actuation line replicas are required, which must be matched as precisely as possible to the lines. if now through the contacts in the voice lines constant Changes occurring in the lines are an exact replica of the same not possible, as a result of which the efficiency of the amplifier devices deteriorates will.

Experience and research have shown that in particular the contacts tend to the mentioned disorders, which are in an unstable situation located, such as B. Normally closed contacts (isolating contacts) of the relay. With these contacts Both contact springs are free to move, and the contact pressure is created by the mutual Generated bias without one of the two springs having a fixed stop. It is generally customary for the actuating spring not to be on the normally closed contacts Support anchor, once to have the guarantee that the prescribed Contact pressure really depends on the preload of the springs, and moreover should a small air gap between the armature and the actuating springs of the individual contacts insist to an even actuation of all contacts and also an even To secure loading of the anchor. This air gap also makes the setting of the relay and its contacts. For working contacts, i.e. those which are actuated when the relay is activated, the malfunctions mentioned occur less or not at all, as the actuating spring is firmly supported on the armature, the position of the contact becomes more stable and it reacts much less to vibrations reacts as the unstable, closed break contact.

Confirmation of what has been said is also given in patent 448702, according to which Isolating contacts (normally closed contacts) in the speech lines for the reasons mentioned above are avoided and short-circuit contacts (working contacts) to avoid the isolating contacts are provided. The patent mentioned protects an arrangement, the purpose of which is to Avoid isolating contacts in the continuous line branch.

On the basis of the previously known material and the experiences and investigations made, it would now be obvious to avoid idle contacts in the speech lines at all, which, however, is not possible with the known systems. So it is z. B. in the first surge receiving device (I. GW) required to separate these backwards during the usual transfer of incoming current surges over a voice line in order to avoid influencing the existing feed relay and the emitted current surges themselves. In the line selector, when the ringing current is sent, unless special separation points are provided in the speech lines, the speech line must be disconnected backwards by the contacts that switch on the ringing current in order to prevent the sending of ringing current to the calling subscriber.

For connecting lines operated with alternating or audio frequency current must in the same way and for the same purpose the voice lines during the transmission of alternating or audio-frequency currents «-earth.

The invention now shows a system in which to avoid it completely of break contacts (isolating contacts) in the speech lines one over several selectors running connection switching means are provided, which only when reporting the called subscriber to a switching criterion sent by the line selector (posting message) the equipment required for the transmission of calls (capacitors, transmitters), which can interfere with the setting processes into the speech lines switch on and switch through the speech lines for the call status.

There are known circuit arrangements in which a through-connection the voice lines only on one of a downstream connection device transmitted signal (e.g. busy tone, dial tone or voice) are switched through, however, these arrangements are limited to only a part of those in the course of a connection lying connecting devices. In addition, in these known arrangements a temporary disconnection of the speech lines during the transmission of alternating or audio frequency surges required in order to affect the reception the signals given by the subsequent connection devices To prevent receiving facilities. To this temporary separation of the speech lines it is necessary to switch on these isolating contacts (break contacts) so that the purpose sought by the invention is not achieved with this known arrangement can be.

To explain the invention, Figs. Z to B.

Fig. Z shows the basic structure of a connection, Fig. 2 a Subscriber connection, Fig. 3 a call finder dialing set, Fig. Q. a first Group selector, Fig. 5 a second group selector, Fig. 6 and 7 the transmission equipment at the two ends of a connecting line operated with alternating or audio frequency current and Fig. 8 a line selector.

According to Fig. R, the calling subscriber T is connected to the first group selector I. GW via a call finder ..S and a front-end selector T% TI ', and via this reaches a second group selector 1I. GW and also a connecting line VL, which is sealed off by the transmission facilities UG and UK at both ends. The calling subscriber reaches a line selector OFLW via the connecting line, which is set to the called subscriber T in a known manner.

Figs. 2 to 8 are based on a system in which the feed current the participant is taken from their connecting body. The invention, however, is also readily applicable to systems in which the two participants are fed from the first group selector or from the line selector.

The signals, signs and signs intended for the calling subscriber and dial tone, are switched on in the first group selector and when the line is busy the connection is released to the call finder dialing set, whereby the subscriber from this receives the busy signal.

The processes from hanging up the calling party to hiring of the AS-V147 set on this and a free first group selector are for the The essence of the invention is irrelevant and will therefore not be described in detail.

In the first group selector (Fig. Q), relay C is activated via line c and relay A via line d . The lines a, b and d are switched through to the calling subscriber (Fig. Z) via the call finder prefix set (Fig. 2), and the relay A is dependent on the contact t 6 of the subscriber T.

Through the contact e z is in the circuit. with the rotary magnet of the group selector, the relay X is energized, whereby D is not influenced, and the contact x5 switches on the external code AZ for the calling party.

Through the first series of dialing current impulses sent by the calling subscriber, the relay A of the first group selector (Fig.q) is de-energized through the opening contact 16 (Fig 2 and 7v 2 the solenoid H of the group selector is controlled. The head contact k2, which opens at the first step of the voter, causes X to be de-energized, so that x5 switches off the official signal. k2 prepares the circuit for the rotary magnet D of the group selector, which is initially interrupted by v3. After the end of the selection process, V drops, and the rotary magnet D is switched on via v3, p 2 and k 2 , the armature contact d V of which is again excited, so that v 3 interrupts D's circuit again. V and D work in an interplay, whereby the rotary magnet lets the switch arms of the group selector turn in gradually. If the group selector has found a free second group selector IL GW, relay P speaks via ei and line c and stops the selector with p 2. Via c 6 and P q, P is connected via a second winding, while P3 plus connects directly to line c and thus blocks the occupied line.

The series of current pulses sent by the calling subscriber to set up the connection are transmitted to line a via P7, mq, y6, c2, gr, ar and pz.

The setting and allocation processes for the second group selector (Fig. 5) are irrelevant to the essence of the invention and are therefore not described in detail explained.

For example, the outgoing transmission of a connecting line VZ (Fig. 6) is occupied by the second group selector. In this case, the relay C responds when the line c is assigned. P is excited via cr and u 2, which is via P q. and h 6 closes a hold circuit across the resistor; T is switched on via c 5 and P 5, and p 6 interrupts the circuit of G. Now the relay U connects via ei and t2 , joins a holding circuit with u 2 and interrupts the connection circuit of P. made the line a A , which it with its contacts a 2 and a q. with alternating current via the connecting line VL.

In the incoming transmission (Fig. 7), the incoming alternating current surges energize relay J, which with its contact i q. an auxiliary relay H controls. The relay C is excited by hz at the first pulse via ez, which closes a holding circuit with c 3 and with c q. The short-circuit of relay E cancels so that it also responds, with e2 the short-circuit circuit is finally stopped and with ez the connection circuit of C is interrupted and C is short-circuited. However, as a result of this short circuit, C has so much dropout delay that it does not drop out for the duration of typical dialing current surges. The contact h 2 results in e q. P switched on, which closes a holding circuit with p 6 via s 6 and the resistor H. The contact p 2 switches - T on, while the circuit of the relay G is interrupted.

The following switching element is assigned with the first current surge via e6 and h6 and is maintained by c 5. The incoming elective current surges are passed on via h5, g2 and line a.

For example, a local long-distance line selector according to Fig. 8 is connected to the incoming transmission of the connecting line V'L, which is energized via the line c, the relay C responding. The dialing current impulses coming in over the line a. operate the relay <4. The relay 1 'is brought through the contact a2 during each series of impulses and the solenoid H of the line selector is controlled with a 6 via 2c 6 and zr-i. 'When the first series of impulses is over, V drops and above positive. q4, z, 2, k2, 6 ", wi and H respond to 6 ', but H is not influenced. 2r 6 switches the lifting magnet H off and the rotary magnet D on, so that the second series of impulses reaches the latter.

While the head contacts k were actuated in the first step of the lifting of the selector, the shaft contacts u are turned over in the first step of rotation , 5; c6, 14 and the wave contact holds zr 2. When the Mrahl ends, 1; ' and when the desired subscriber is free, the test relay P connects via w2, 2t4, e6 and v 5. P connects to relay C via a second winding and its contact P 4 and blocks the occupied subscriber with p 3 by directly applying plus to line C. The relay L £, which was de-energized by z-5, has a drop-out delay of about 60 ms, so that a corresponding current surge via the line via plus, w2,114, P i and y4 b is sent backwards, which indicates that the desired participant is free.

As soon as L- has dropped out, the relay Q responds via 114 and p 6, which prepares the ringing circuit with q i and q2. Q3 de-energizes C and prepares a circuit for a second winding of 1E '. A second winding of .4 is switched on via the shaft contact u- 2, c 5, V i, v 2 and p 5, so that A responds and is in this circuit with c24. binds so that A remains excited when C drops and c5 is opened. Through contact a5, ringing current is sent to the desired subscriber via q2. The contact ai applies the second winding of 1- to the line RK, via which I 'receives power after about 1 second, responds and binds itself via V3. The subscriber receives the first call until V is answered. After I 'has responded, relay A is connected to the 10-second switch via c3 through z = i, so that the subscriber is now called rhythmically.

That of the local long-distance line, counter when the desired participant is free Free pulse sent backwards via line b excited in the incoming transmission (Fig. 7) the relay S, which it with alternating current through its contacts s i and s 2 resends.

Through the contact s6 the holding circuit of P interrupted, which, however, does not drop, since via s6 or p 6 in the circuit with P the capacitor EC 2 charges and this charging current prevents P from falling.

In the outgoing transmission (Fig. 6) the relay J is made to respond by the incoming free pulse with alternating current, "- which with its contact i 4. switches on the auxiliary relay H. The free pulse with plus is now passed on via line b via c 5 and k 5. In this transmission, too, there is temporarily no current due to approx. 6 P, but kept by the charging current of the capacitor EC 2.

In the first group selector (Fig. 4) the relay 3I responds with the free pulse and switches on Y via P7, 232.4, x6 and a3, and as soon as the pulse has ended and 3I drops out, P7 ,; 11 4, y6, cI , Winding II held by Y and IY and X energized. At the same time, via the plus,; ni and v 2 I- lying on the line d from the subscriber, temporarily switched on, so that during the excitation time of I 'via v 6, Y5,; 11 5, x 5 and g 4 the calling subscriber the distant signal is transmitted, while the rhythmically given dial tone is switched on after 1 'falls above 7.6. By contact mi A was temporarily de-energized, and rc by the contact 4 C has been short-circuited, but the cüährend the pulse duration does not drop.

If the called subscriber answers, his relay T (Fig. I) responds and puts plus on line d, so that relay Y and L respond at the same time in the local long-distance line selector (Fig. 8). Contact vi closes a holding circuit for 1-, y2 switches: I off and thus interrupts the transmission of calls, y5 and v6 switch the speech line through, and via 1V4. and qi is placed plus on line b. Contact y3 closes a holding circuit for L ", so that it remains energized even after Q has dropped. Q is de-energized by tr4 and drops off with a delay of about 300 ms, so that when qi is opened, the current impulse emitted via line b is limited to this time.

The contact q3 switches 1; "off, which with v i the call control circuit for .d finally interrupts. Relay C can no longer respond via q3 because both the head contact k i and c 2 are open.

The hanging message given with plus via line b with a duration of 300 ms excites the relay S in the incoming transmission (Fig.7), which it forwards through si and s2 with alternating current. The contact s 6 again interrupts the holding circuit of P, which, however, now drops because the current interruption by s 6 outlasts the charging current of the capacitor EC 2. P 6 interrupts the holding circuit for P, and P2 is de-energized, which, however, has a dropout delay of about 500 rns and does not drop out during the unhooking message. If the current surge is ended, then G is switched on via c3, t2, s4, P4 and h4, which switches through the speech line with its contacts g2 and g6 and closes a new circuit for T with 94 so that it remains energized.

In the outgoing transmission (Fig. 6), the unhooking message J excited, which turns on with i 4 H, so that over c 5 and h 5 plus again for the duration of 3oo ms is applied to line b.

In the outgoing transmission, too, P is switched off by h 6, and P 5 de-energizes T, which, however, survives the unhooking message. After the end of the current impulse, G speaks via c 5, t 6, h 4, p 6 and a 6 and switches the speech lines through with g2 and g6, while .T is held by 94.

In the first group selector (Fig. 4) the relay M is energized by the unhooking message, and m 4 switches Y off, while X remains energized via m 4 and x 6 for the duration of the current surge. After M, X drops off with a slight delay, so that via P 7, m4, y6, e g-, xi and z; 2 G responds and holds up with g 5 via a second winding. The speech line is switched through by the contacts 94 and g6. The contacts 94, x5 and y5 interrupt the circuit of the dial character FZ. This establishes the local connection from the calling subscriber to the called subscriber.

The processes involved in breaking the connection are essential to the essence of the Invention without meaning and are therefore not explained.

If the called subscriber is busy, the relay P in the local long-distance line selector (Fig.8) cannot respond and U drops out after V, so that via ze) 2, u4, pi: and y 4 plus is permanently connected to line b.

In the incoming transmission (Fig. 7) o thereby speaks to U and sends alternating current with s i and s2 via the connecting line VZ. By s 6 becomes P is switched off and drops after the end of the charging current surge of the capacitor EC 2 and interrupts the circuit of T with p #z, which also drops out. By the contact 14 S is switched off and thus the further emission of alternating current prevented via the connecting line VL.

In the outgoing transmission (Fig. 6), J is excited by the alternating current surge and thus H is switched on, which applies plus to line b via c2 and h5. Due to h 6, P also drops here and then, when P 5 is de-energized, also T, whereby the drop-out time of the relay T is shorter than that in the incoming transformer according to Fig. 6, in order to ensure the process. After the end of the current surge, plus remains connected to line b via c2, u3, 14 and g6.

In the first group selector (Fig. 4) M is excited by the busy message, and mi switches off A, which short-circuits with a ¢ C, which now drops out and interrupts the receipt circuit with c3. As a result, the relay P in the AS-VW set (Fig. 3) drops out and sends the busy signal to the line leading to the subscriber with P 2 via a7. The relay C remains until the calling subscriber hangs up on the line d, c 4, P 3, a 6, C, c 6 and DA.

When relay C in the first group selector drops out (Fig. 4) the release of the established connection initiated as it is for the essence of the invention is of no importance, is not described in detail.

As can be seen from the above description, are during the Adjustment processes the speech lines in the first group selector (Fig. 4) and in the Transmission devices (Fig. 6 and 7) the speech lines through the contacts relay G and in the line selector (Fig. 8) are interrupted by the contacts of relay Y. and are only switched through when the called subscriber answers.

After the conversation and also with flak in long-distance traffic, which here, since it is irrelevant to the essence of the invention, will not be described the voice lines disconnected immediately. Through this separation of the speech lines In the aforementioned connecting organs, it is possible to have break contacts in the speech lines to be avoided entirely.

As mentioned at the beginning, the arrangement is not just based on systems limited in which the subscribers are fed from their connecting body, it also relates to systems in which the two participants are fed is created in the first group selector or in the line selector.

Claims (1)

PATENT CLAIM: Circuit arrangement for telephone systems with dialer operation and main and sub-exchanges, characterized in that for complete Avoidance of break contacts (isolating contacts) in the speech lines of an over multiple selectors running connection switching means (relay G in the first group selector, Fig. 4, relay G in the outgoing transmission, Fig. 6, relay G in the incoming Transmission, Fig. 7 and relay Y in the line selector, Fig.8) are provided which only when the called subscriber reports to one sent by the line selector . Switching criterion (posting message) those required for transferring calls Facilities (capacitors, Transformer), which the setting processes can interfere, turn on the speech lines and the speech lines switch through for the call status. To delimit the subject matter of the invention From the state of the art, the following publication is to be considered in the granting procedure drawn: German patent specification No. 643 0z5.