DE702945C - Circuit arrangement for telephone systems with Wae - Google Patents

Description

Circuit arrangement for telephone systems with dialer operation and sealed off Connecting lines The invention relates to a circuit arrangement for Telephone systems with dialer operation, in which the switching operations are sealed off Connecting cables through inductively generated direct current surges or alternating current surges be transmitted. If in such systems during a connection in both Direction switching operations have to be transmitted, it is difficult ensure release at every stage of the connection. It can happen, that the tripping does not come through as a result of the opposing current surges. This danger exists especially if the transmission of the trip happens by chance coincides in time with a switching process arriving from the opposite direction. It is now already for connecting lines operated exclusively with alternating current became known, the penetration of the triggering by one opposite the return signals to secure particularly long power surges. Only this type of release can be Do not use with the so-called inductive selection, as a single one is particularly long Induction surge cannot be generated or when a long alternating current surge for the tripping is used, this is not ensured because the tripping current surge can end with any half-wave (positive or negative) and thus the polarized receiving relays no different characteristics compared to the dialing pulses receives. Ensuring tripping in the still known way by a so. large number of power surges, that they are through the dial the participant cannot be generated requires a relatively large amount of time and In addition, special switching means (followers) at the incoming line end for tapping the power surges.

It is finite for connecting cables operated with inductive direct current surges an arrangement has already become known, in which the penetration of the triggering a larger number of pulses compared to the return pulses is ensured. This arrangement always requires that the last impulse be a definite one Direction is. Accordingly, in the one known form of solution, a number only positive induction pulses are sent out for triggering, while at the other known embodiment, although induction shocks of alternating direction be sent out, but care must be taken that the last impulse is always such a positive direction is. The first-mentioned type of solution has the disadvantage that the successive impulses of induction in the same direction as a result of the increasing Bias of the ring transformer always in the same sense in its amplitude decrease rapidly and therefore the final absorption of the fundamental trigger impulse but is not secured. This error can even occur with the first trigger pulse occur when, as is particularly the case with the transmission of return signals by alternating current can happen, the ring transformer is already in an unfavorable state due to the return signals Sense was pre-magnetized. In order to rule out this error, the invention also wants use induction pulses in alternating directions to trigger. Compared to the known solution with several induction surges in alternating direction has the invention the advantage that the aggravating and not with the known arrangement Safety condition to be met by an end pulse entirely. certain direction, also an unnecessary recruitment of voters as a result of equality the dialing and tripping currents occurs when the caller is already tripping initiates before the end of the number dialing, is avoided. According to the invention this is achieved in that the triggering until the arrival of the subscriber message pulse by a single impulse of induction in a certain direction, after this point in time on the other hand by a sequence of induction shocks in changing direction or an alternating current train, which can end with a half-wave in any direction, is transmitted and Switching means in the incoming transmitter after the called subscriber has reported tripping after recording a single half-wave for tripping secure the intended direction regardless of the direction of subsequent half-waves.

The accompanying figures show two exemplary embodiments of the invention. Fig. I shows an embodiment in which all switching operations in the direction from the outgoing to the incoming end of the connection line by inductive direct current surges be transmitted. In particular, the tripping is after the by reporting the called Subscriber's given characteristic of the start of the conversation by a series of induction surges in changing direction, separated by short pauses.

In contrast, Figure 2 shows an embodiment in which the Triggering after the called party has reported, not by inductive direct current surges, but is transmitted by an alternating current train.

In the opposite direction, the switching operations are carried out in both exemplary embodiments transmitted by alternating current surges. Instead of the alternating current surges could of course the switching processes are also transmitted in the opposite direction by means of inductive direct current surges without changing anything in the essence of the invention.

In order to ensure the penetration of the tripping current surges, their frequency is in a known manner a higher frequency than the frequency of that transmitted in the opposite direction Power surges. In addition, the duration of the tripping current surges extends at least over the duration of one of the current impulses arriving from the opposite direction.

The exemplary embodiments show an arrangement with a connecting line for directed traffic. The invention can of course also be used in double apply directed connection traffic.

The mode of operation of the arrangement shown in Fig. I is as follows: When the transformer Ue is occupied at the outgoing end of the connecting line VL by an upstream group selector, the occupancy relay Cl is excited via the c wire: earth, test relay, test arm of the upstream group selector, wire c , Contacts 11 x "12 hl, 13 b1, 15 cl, winding II of relay Cl, battery, earth. Relay C, switches its high-resistance winding I in series with winding II into the occupancy circuit via contact iq.c and remains independent of relays X1, Hl and B, via this contact. Relay C, closes the following circuit for relay A,: earth, contact 21 il, winding II of relay A "contact igxl, winding III of relay C" contact 26 cl, battery, earth. Except for relay AI, relay Cl closes the following circuit via winding I of transformer Tr: earth, contacts 9 bi, 30 x1, 32 c1, winding I of transformer Tr, battery, earth in winding II of the T ransformators Tr induces a current surge, but this has no effect since the contact 35 a1 is not yet closed. Relay A1 closes the following circuit for relay Bi: earth, contacts 21 il, 17 a1, winding I of relay Bi, winding I of relay V1, contact 26 cl, battery, earth. The relay Bi responds to and in series with this also the relay V1. Relay Bi interrupts the circuit at contact 9 bi via winding I of transformer Tr. As a result, an induction surge is generated in winding II of transformer Tr, the direction of which is designated as the negative direction. This current surge, which is via the contacts 35 a1. 37 ei, 38 v1 or, after the relay V1 has responded, directly via contact 39v, via the primary winding of the ring transformer blocking the line, is transmitted via the connecting line y L to the incoming transformer Ue. However, the polarization of the polarized receiving relay P2 located in a bridge to the line is such that this current surge does not result in the armature of the relay being turned over. Rather, the current surge serves to completely demagnetize the locking ring transformer from any residual field that may still be present. Relay Bi closes the following circuit for relay X1: earth, contact 21 il, winding I of relay X1, contacts 18 bi, 26c1, battery, earth. The relay X1 responds and closes a new circuit via the winding I of the transformer Tr: earth, contacts iobi, 3i .r1, 32 cl, winding I of the transformer Tr, battery, earth. By closing this circuit, an induction surge in a positive direction is generated in the winding II of the transformer Tr, which via the connecting line VL to the polarized receiving relay P2 in the incoming transformer Ue. got. As will be shown later, this results in the assignment of the transformer Ue. In the outgoing transformer Uel, after energizing relay X1 at contact ig x1, the circuit for winding II of relay A1 is interrupted. Relay A1 drops out. When relay Al drops out, the circuit for relays Bi and V1 is opened at contact 17a1. The relays Bi and V1 drop out, the latter delayed as a result of its winding II short-circuited via contact: 2g y. When relay B1 drops out, the circuit via winding I of transformer Tr is interrupted at contact To b1. By opening this circuit, a negative induction surge is generated in the winding II- of the transformer Tr, which, since the contact 39 v1 is still closed, reaches the polarized receiving relay P2 of the transformer Ue via the connecting line TL. The armature of the relay P2 is thereby returned to its initial position. In the outgoing transformer Uel, after the relay Bi drops out, the circuit for winding I of relay X1 at contact 18 bi is interrupted, but the relay remains in the following circuit: earth, contacts 46 x1, So lt, or 4.8 a1, winding II of relay X1, battery, earth.

In the incoming transformer Ue, as already mentioned, the occupancy is initiated by the positive occupancy current surge, which runs over the winding I of the relay P2 that is in a bridge to the line. It should be said in advance that the relay E2 is energized in the idle state of the system via its high-resistance winding I and the c-wire to the following group selector. As a result, the circuit for the receiving relay P2 is closed via the closed contacts 61e and 64e2. Relay P2 closes the following circuit for relay A2 after it has responded: earth, contacts 90 P2, 78 f2, winding of relay A2, battery, earth. Relay A2 responds and closes the following circuit for occupancy relay C2: Earth, winding of relay C2, contacts Toi a2, IOI i12, resistor Wie, battery, earth. Relay C2 responds and remains independent of relays A2 and T12 in the following circuit: Earth, winding of relay C2, contacts gg f2, 107c "Resistance like, battery, earth. Relay C2 also occupies the c-wire through direct earthing the connected group selector via contact 76 c2 in a known manner. Since the winding I of the relay E2 is short-circuited, the relay E? T12, contacts 89M2, Tob f2, winding II of relay E2, battery, earth.- In this circuit the delay relay T12 also responds Dropped, because the negative induction shock shortly afterwards causes relay P2 and thus also relay A2 to drop again before relay C2 drops out. Relay T12 is then short-circuited via contact 87 a2 and comes on s on the one hand to waste. After relay A2 drops out, the following circuit for relay U2 is closed: earth, contacts 8 T s2, 86 c2, 87 cal, winding II of relay U2, contacts 88 a2, 83 m-, resistor Wi3, battery, earth. Relay U2 prepares via its contact 8 u2 a holding circuit containing its two windings I and 1I in series, which is independent of relay A2. Furthermore, relay U2 prepares a circuit for its winding III by closing its contact 9.4 u2.

When dialing numbers, the group dialer upstream of the transmitter Uel is used intermittently earth is applied to the a-wire and thereby the winding I of the relay Al des Transformer Uel energized: Earth in the group selector, wire a, contacts i hl, 56x1, winding I of relay Al, contacts 3 y1, 5 e1, battery, earth. The relay Al responds to and energizes relays B1 and hl via contact 17 a1. Relay hl acts as a delay relay during the series of impulses. Relay B1 closes when it is triggered via contact io b1 a circuit through the winding l of the transformer Tr and gives thereby a positive induction surge via the connecting line VL. As well as the relay Al drops out, the circuit for relay B1, the relay, is also interrupted B1 comes to waste and breaks the circuit across winding I of the transformer Tr. Daduxch, a negative induction surge is sent over the connection line. In this way, when dialing numbers, positive and negative induction surges will alternate transmitted via the connection line.

In the incoming transformer Ue. When dialing the number, the armature of the relay P2 is switched to the working position and shortly thereafter back to the rest position by a pair of induction shocks in a positive and negative direction. The contact go p2 is temporarily closed. When the contact gop closes, the relay A2 is energized. Relay A2 interrupts the short circuit of the delay relay h2 at contact 87a2, so that this also responds. Relay h2 holds during the series of impulses. If contact 88a2 is opened during the impulse, relay U2 is kept energized in the following circuit: earth, contacts 8 i s2, 86c2, winding I of relay h2, contact 89m-2, windings N and I of relay U2, contacts 84u- , 83m2, resistance Wi3, battery, earth. The current impulses are transmitted through the relay AZ in the following circuit to the connected group selector: earth, contacts 70 u2, 68 a2, 69 c2, wire a, impulse receiving relay of the following group selector, battery, earth. During the series of impulses, control voltage is applied to the b-wire in the following circuit: Earth, battery, contacts 75 m2, 74s2, 72 v2, wire b. The occupancy relay C =, which is short-circuited during the current impulses via contact i02 v2 and the impulsively closed contact 103a, does not drop out during a series of numbered current impulses. In addition, during a series of current impulses, contact 65 v2 interrupts the a-wire in the direction towards the blocking transformer in order to avoid undesired charging of the speech capacitor due to the current impulse transmission.

Let us now consider the case that the calling subscriber hangs up his receiver while dialing the number, that is to say without the called subscriber having reported. This initiates the trip. In the group selector that has occupied the outgoing transformer Uel, the c-wire is interrupted. The relay Cl of the transformer Uel comes to waste. As a result, the relay Al is re-energized in the following circuits: earth, contact 21 il, winding 1Z of relay Al, contacts 20x1, 23y1, winding II of relay Hl, contacts 25 a1, 27 cl, battery, earth. Before the relay Hl, which responds with a delay, is excited in this circuit, its winding II is already short-circuited again via contact 24a. By opening the contact 25 a1, the short circuit for the winding I of the relay El is interrupted. The relay El comes in series with the winding 1I of the relay Al, albeit somewhat delayed, to respond. When relay Al responds, the following circuit is formed via winding I of transformer Tr: earth, contacts 4oal, 33 w winding I of transformer Tr, battery, earth. This induces a positive current surge in winding II of the transformer Tr, which, as long as the relay El has not yet responded, via this transformer winding and the contacts 35 a1, 37e "38v, to the interlocking transformer and from there via the connecting line VZ to the incoming one Transmitter Ue2 is transmitted. The subsequent negative induction surge is suppressed by the response of the relay El, which interrupts the transmission circuit at contact 37 e1. As soon as the relay El has responded, the following circuit for the relay B1 is closed: Earth, contacts 46 x1, 50111, 4.3 v1, 42 e1, 45 cl, winding II of relay B1, battery, earth. Relay B1 short-circuits the holding winding II of relay X1 through its contact 55 b1. Relay X1 drops out and interrupts the circuit for the Winding II of relay B1, which drops out. When relay X1 drops out, the circuit for relays Al and El is also canceled at contact 20x1 broke. The two relays drop out. All relays of the transformer Uel are again in the rest position.

In the transformer Ue, the receiving relay P2 is excited by the positive triggering induction shock via the winding I. Contact gop2 closes an excitation circuit for relay A2. Relay A2 interrupts the short circuit of relay T12 at contact 87a2, and relay V2 also responds. Now the occupancy relay C2 is short-circuited via the contacts v2 and 103 a2 so long that it comes to waste. When relay C2 drops out, the assignment of the c-wire to the connected group selector at contact 76 c2 is canceled and its triggering is initiated. After relay C2 has dropped out, the circuit for relays V2 and E2 is interrupted by opening contact 86 c2; the circuit of relay U .. is also interrupted. The relays come to waste. This closes the following circuit for relay F2: earth, winding II of relay F2, contacts 97 c2, 98 e2, battery, earth. Relay F2 responds and closes the following circuit for winding II of relay P2: earth, contacts 93 u2, 92 f2, winding II of relay P2, battery, earth. The armature of relay P2 is returned to the rest position via this winding, which is connected in the opposite direction to winding I. As soon as the group selector occupied by the transmitter Ue has triggered, the circuit for relay E2 is restored in a known manner via a head contact (not shown) of this selector and the c-wire, which on the one hand interrupts the circuit of relay F2 on contact 98 e2 and on the other hand the during the de-energization of the relay E2 via the contacts 62 e2 and 63 e2, the reverse alternating current applied via the connecting line is cut off again.

In the transformer Uei is through the backwards over the connection line VL transmitted reverse alternating current energizes relay J1 in the following circuit: Transformer windings, contacts 38 v1, 36v, capacitor, winding of the relay 1 "transformer winding. Relay J1 closes the following circuit for relay HI: Earth, contact 22 ü, winding III of relay H1, battery, earth. Relay Hl interrupts when it opens of contact 12 hl the c-wire and thus prevents premature re-assignment of the transformer Uel. As soon as the release is completed at the incoming line end is, relays T1 and H1 drop out and the lock is released.

Let us now consider the case that the release is initiated after the called subscriber has reported. When the called party lifts the receiver, the downstream line selector applies counting voltage to the b-wire. In the incoming transformer Ue2, the relay S2 responds in the following circuit: voltage on the b-wire, contact 71v2, winding II of relay S2, contacts 67 ira.2, 70u2, earth. Relay S2 interrupts the holding circuit of winding II of relay E2 at contact 8 t s2, which is released. Relay U2, whose excitation circuit is also interrupted by opening contact 8 i s2, is held in the following circuit: earth, contacts 94u2, 95 s2, winding III of relay U2, battery, earth. Relay E2 temporarily applies the alternating current source WO backwards to the connecting line VL via its contacts 62 e2 and 63 e2. The connection of the alternating current to the connection line is terminated again by the fact that, after the relay E2 has dropped out, the relay V @ is energized in the following circuits: earth, contact io4v2, winding II of relay l'2, contacts 96c2, 98e2, battery, earth. Relay V2 responds and interrupts the short circuit for winding I of relay M2 at contact 104v2, so that it responds in series with relay V2. Relay M2 remains in the following circuits: earth, winding II of relay M2, contact 82 m2, resistor Wi3, battery, earth. The circuit for winding II of relay S2, which was maintained after energizing relay V2, via the b-wire and contacts 72v2, 73s2, is now interrupted at contact 67 M2. Via the closed contact 66 yya, the two windings II and I of the relay S2 are connected one behind the other in a bridge to the speech wires in order to serve as a termination signal relay when the connection is terminated. Relay S2 comes to waste. As a result, the relay E2 is re-energized via its winding II and, by opening the contacts 62 e2 or 63 e2, switches off the AC power source WO again from the connection line; on the other hand, the two speech wires are switched through again through the contacts 61 e2 and 64e2. - Relay h2, the circuit of which is interrupted at contact 98 e2, drops out. In turn, it switches the two speech wires through to contacts 65 v2 and 71 zf.

In the outgoing transmitter Uel, the alternating current relay J1 is energized by the short alternating current surge transmitted when the called subscriber reported. Relay J1 temporarily energizes relay H1 via its contact 22 il. Relay Hl closes the following circuit for relay Y1: earth, contacts 46 x1, 49 h1, 5.1 e1, winding of relay Y "resistance Wii, battery, earth. Relay Y1 responds and remains after the end of the current surge, after which the Relay Hl drops out, in the following circuit: earth, contact-16x "winding II of relay El, contact 52y" winding of relay Y1, resistor Wil, battery, earth. In this circuit, relay El also responds. Contact 3y1 is the Winding I of the surge receiving relay Al disconnected from the incoming a-wire. Via contact 6 e1 and the choke coil Drb, counting voltage is applied to the b-wire. Via contact 4e1 and the choke coil Dra, the transmission of the final signal is prepared.

If the calling subscriber hangs up his receiver after the end of the conversation, the occupancy relay Cl in the outgoing transformer Uel again falls. The relay A1 is excited in the following circuit: earth, contact 2 1 il, winding 1I of relay Al, contact ao x1, windings I and II of relay Hl, contacts z5 a1, 27c, battery, earth. Relay Al closes its contact 4o a, as a result of which a circuit is closed via the winding I of the transformer Tr, which results in the transmission of a positive induction surge via the connecting line. In series with the relay A1, the relay Hl also responds, but with a delay. The excitation of the relay El via its winding I in series with the relays Hl and Al has no effect, since the relay El was already energized via its winding II. In front of the relay Hl, the relay k'1 is energized in the following circuit: earth, winding II of the ret relay V1, contacts 28 y1, 27 cl, battery. Earth. Relay L'1 short-circuits relay Y1 via its contact io8v1, so that it drops out after a delay. Relay Y1 in turn short-circuits the winding II of relay L'1 via contact 29y1, so that this relay also drops out with a delay. During the release time of the relay V, a sequence of induction surges in alternating directions is transmitted via the connection line. This is done by interrupting the hold circuit for the winding 1I of the relay X1 at the contacts 50 hl and 48 a1 after the relays Al and Hl have responded. Relay X1 drops out and interrupts the circuit for relay Al at contact 20 x1. The relay Al drops out, while the relay Hl still holds. When relay A1 drops out, the circuit via winding I of transformer Tr at contact 4oal is interrupted and, at the same time, a new excitation circuit for relay X1 is closed via contact 41 a1: earth, contacts 41 a1, 44v1, winding II of relay X1, battery, Earth. The relay X1 responds again and switches the winding 1I of the relay A1 back into the already described excitation circuit via contact 20 _i-1. Relay A1 responds again, which results in the emission of another positive induction shock. As soon as relay A1 has responded, the circuit for relay X is interrupted again at contacts 41a, or 48a, and 5o h. Relay X1 drops out again and interrupts the circuit of winding II of relay Al. The drop in relay A1 results in the interruption of the circuit via winding I of the transformer Tr and thus the emission of a negative induction surge. As soon as relay A1 has dropped out, an excitation circuit for winding II of relay X1 is recently closed. Relay X1 responds and in turn closes an excitation circuit for winding 1I of relay Al. This game is repeated until the relay hl has dropped out. The release time of the relay V2 is dimensioned in such a way that approximately three changes of positive and negative pulses are sent out. The pause between the current impulses, ie the frequency of the current impulses, is such that in any case a positive induction impulse falls into the pause of the final signal impulses transmitted backwards approximately at the same time, so that the triggering criterion is safely passed.

As soon as a positive tripping current surge is received by the relay P2 in the incoming transformer UeE, contact 9o p2 is closed. However, since relay M $ is excited, relay FZ is also excited via contact 9o p2 in addition to relay AZ in the following circuit: earth, contacts 90P2, 79 »a2, winding I of relay F2, battery, earth. Relay FZ immediately interrupts the circuit for relay A2 at contact 78f2. After relay F has responded, the holding circuit for relay C2 is interrupted at contact 99f2. Relay F2 remains until relay C2 has dropped out in the following circuit: earth, winding II of relay FE, contacts ioo f2, 107 c2, resistance Wiq, battery, earth. The relocation of the armature of the relay P due to a subsequent negative current surge and the opening of the contact 9o p2 caused by this has no effect in this case, since the relay FZ holds locally via its winding 1I. After relay FE has responded, the circuit for the holding winding 1I of relay EZ is interrupted at contact i06 f =. The relay E = drops out and on the one hand interrupts the receiving circuit for the relay P2, on the other hand there is reverse alternating current through the connecting line. As soon as relay C has dropped out, the tripping of the downstream voters is initiated, as already described. After relay C2 drops out, the circuit for winding II of relay F2 at contact 107 c2 is interrupted, but the relay is still held via contacts 97 c2, 98 e2 until the downstream group selector has triggered and the c- Core the high-resistance winding I of the relay E2 has been re-energized. This opens the circuit for winding II of relay F2 at contact 98 e2. After the relay C2 drops out, the relay M2 is caused to drop out by short-circuiting the contacts 81 s2, 85 c2. The transformer is now ready for a new assignment.

If the triggering initiated by the calling subscriber coincides with the final signaling initiated when the called subscriber hangs up, the following switching processes take place: If the called subscriber hangs up his receiver, the called subscriber's line selector is connected to the a-wire earth and the relay S2 of the transformer Ue, energized in the following circuits: earth on the a-wire in the line selector, contacts 69 c2, 65 v2, winding I of relay S2, contact 661n, winding II of the relay.% contact 71 v2, voltage on the b-core in the line selector. Relay S2 responds and interrupts the circuit for winding II of relay E2 at contact 8i s2. Relay E2 drops out and thereby emits an alternating current pulse backwards via the connecting line VL. When relay E drops out, the following circuit for relay T12 is closed: earth, contact io4v2, winding II of relay T12, contacts 96 c2, 98 e2, battery, earth. The relay T12 responds and interrupts the circuit for the relay S2 at contact 65 v2. Relay S2 drops out and closes the circuit for relay F_2 at contact 8i s2. Relay E2 responds and terminates the reverse alternating current pulse. As soon as relay E2 responds, the circuit for relay V2 is opened at contact 98 e2. Relay T12 drops out and closes the circuit for relay S2 at contact 65v2. Relay S2 responds again and causes relay E2 to drop, whereby a new alternating current pulse is sent backwards over the connecting line. This game is repeated until the triggering current impulses from the transformer Uel, which are sent out when the calling subscriber hangs up, arrive. The first positive induction surge arriving in a pause between the final signal impulses causes the relay P ... Relay P2 to close its contact gop, thus switching on relay F2 via contact 79m2. Relay F2 lasts through its winding II until relay C2 drops out and immediately and permanently interrupts the circuit of relay E2 at contact io6 f2, which applies reverse alternating current. The relay P2 is returned to its rest position via its winding II after the relay F2 has responded in the following local circuit: earth, contacts 93 u2, 92f, winding II of relay P2, battery, earth. After relay C2 has dropped out and relay E2 has responded via its @ Äricklung I, relay F2 finally drops. After relay C2 has dropped out, relay M2 is short-circuited via contact 85 c2 and also drops out.

In the outgoing transformer Uel becomes independent of the approximately simultaneously End signal signals arriving from the opposite direction trigger the emission of the triggering induction surge causes as soon as the caller by hanging up his handset the identifier for the Has triggered. As soon as in the outgoing transformer U e, the occupancy relay Cl has dropped out, in addition to relay A1, relay V1 also responds immediately, which has previously been used for receiving the final signal through the relay J1 contacts 38 v1, 36 e1 maintained circuit at contact 38v, opens and at the same time the transmission circuit for the tripping currents via contact 39 v1 closes.

Let us now consider the case that in the outgoing transmitter, at the same time as the triggering initiated by the calling party, the signaling pulse of the called party arrives from the opposite direction. In this case, too, the transmission of the triggering current impulses must be guaranteed, since the final signal impulses of the called party can also arrive immediately after the signal impulse. The most unfavorable moment is the one in which, after the initiation of tripping in the outgoing transformer Uel, relay Cl has dropped out and relays Al and El are already energized. Since in this case the relays Y1 and V1 are not yet energized, the receiving circuit for the incoming signal pulse is initially maintained via contacts 38 v1 and 36 e1, so that the relay h is energized. Since relay El is also excited, the excitation circuit for relay Y1 at contact 51 e1 is still open. Relay J1 interrupts the circuit of relay Al at contact 2i il , which drops out, and energizes via contact: 2: 2i, the relay Hl. Relay Hl spricjit on. In the meantime, relay B was energized via earth, contacts 46 x1, 5014, 43 vh 42e., 45c "winding II of relay B1, battery, earth. Relay B, via contact 55 b1, shorts relay X, so that due to the delay, this lasts until the signaling pulse has ended. Relay Bi, whose excitation circuit was also opened after relay Hl responded, is delayed by short-circuiting its winding I via contact 16 ei in the dropout position. During the dropout time of relay B, and Hl, relay Y, is excited in the following circuit: earth, contacts 46x1, 4911v 53 bi, winding of relay Y1, resistor Wii, battery, earth. Via contact 28y, relay V now also responds Circuit of relay B, interrupted, which drops with a delay and the short circuit of relay Y is completed at contact 54. As soon as the signaling pulse is over, relay A1 responds again, in series with it relay H is held X, to the rubbish. That already described The play between relays A1 and X1, which is used to generate the trigger pulses, sets in.

Fig. 2 shows a modification of the inventive concept, which by minor changes in the outgoing transmitter Ue shown in FIG will. As a result, instead of several alternations of positive and negative induction surges as trigger impulses after reporting the called subscriber, the half-waves of a low-frequency alternating current, for example a 25-period alternating current, transfer.

The same reference numerals are used for the modified parts of the transformer U ei as in FIG. I. The modifications are indicated by dashed lines showing the current flows. In detail, the mode of operation is as follows: If the connection according to the arrangement shown in FIG. the occupancy relay C, to the waste. After relay C, relays, since relays X1, Ei and Y, are energized, relays A1 and V1 respond immediately, and later relay H, too. via contact 58v, the AC source Q of 25 Hz is applied to the winding I of the transformer Tr. Via the winding II of the transformer Tr and the contact 39v, the alternating current is transmitted via the connecting line VL to the incoming transformer (Je The alternating current source Q remains connected to the connection line long enough to transmit a positive half-wave in any case to the terminating signal pulses arriving approximately simultaneously from the opposite direction. The release of relay V depends on the response time of relay B "the release time of the relay X" the release time of the relay Y "also has its own release time delayed by a winding short circuit y1, 42 ei, 45 c1, winding II of relay Bi, battery, earth, relay X1, which s I kept in series with winding II of relay A1 in the following circuit after relay H responded: earth, contacts 46x1, 6oy1, winding II of relay X1, battery, earth, will be short-circuited via contact 55 bi after relay Bi has responded and brought to waste with a delay. When relay X drops out, the circuit for relays Y and Bi at contact 46x1 is interrupted. The circuit for relays A1, H, and Ei is opened at contact 20 x. The relays come to waste. After relay Y has dropped out, relay V1, which is short-circuited via contact 29 y, also drops out with a delay. After the relay V has dropped out, the alternating current source Q is switched off from the connecting line VL by opening the contact 58v.

Claims (5)

PATCNTANSPRÜCIIR: I. Circuit arrangement for telephone systems with Selector operation and cordoned off connection lines, via which the switching processes are transmitted by inductively generated direct current surges or alternating current surges, characterized in that the triggering until the arrival of the subscriber message pulse by a single impulse of induction in a certain direction, after this point in time on the other hand by a sequence of induction shocks in changing direction or an alternating current train, which can end with a half-wave of any kind, is transmitted and Switching means (M2, F2) in the incoming transmitter after the called subscriber has reported tripping after recording a single half-wave for tripping secure the intended direction regardless of the direction of subsequent half-waves. 2. Circuit arrangement according to claim I, characterized in that the frequency after the start of the conversation Transmission of triggering Result of induction surges or the alternating current is higher than the frequency of the Signals transmitted in the opposite direction (e.g. termination characters). 3. Circuit arrangement according to claim i, characterized in that the duration after the start of the conversation the triggering sequence of induction surges or the alternating current train is larger is than the duration of one of the impulses transmitted in the opposite direction. q .. Circuit arrangement according to claims i to 3, characterized in that the signals are in the opposite direction (e.g. for the start of a conversation or the end signal) by a series of induction surges alternating direction or by alternating current surges. 5. Circuit arrangement according to claim i, characterized in that switching means (B1, X1, Y1, V1) in the outgoing transmission (Uel) immediately upon receipt of the subscriber message pulse after triggering has been initiated, initially bridge the duration of this feedback and then the emission of the sequence of induction surges or of the AC train.