DE696329C - Circuit arrangement for telecommunication, especially telephone systems with company lines - Google Patents

Description

Circuit arrangement for telecommunications, in particular telephone systems with company management The automatic call from participants in a company management is also when there is an intercourse between participants of the same company management is not intended, not always to be carried out without operational difficulty. Even the disconnection of the ringing current when reporting the desired position offers this often difficulty, even if by lifting the handset and closing the DC bridge as when selecting a single line subscriber, the reporting criterion is given and in the usual way the disabling of the call facility initiated in the exchange.

More noticeable difficulties arise when the participants a company management also among each other via the company management in traffic should kick. For systems with microphone feed from the battery of an exchange (ZB operation), depending on the choice of the desired branch point, the calling branch point is located with their speaking machines already in the bridge to the company management. The license plate for the call disconnection, which consists in the direct current path through the speech sets, is already used elsewhere.

In order to also call the company management in these cases To be able to perform lying participant, is the participation in known arrangements of the subscriber at the calling branch point. This must either press a special call button or he has to hang up his handset. To Hang up the The caller takes turns calling the handset and the desired junction. Finds out about the reporting of the desired participant the calling subscriber by not having to operate his alarm clock these arrangements have the disadvantage that a call is made by the subscriber of his choice of a desired participant must always distinguish whether this participant is his own Company management is connected or to a third-party management. On which line the desired subscriber is, whether on someone else's line or on your own line, it is decisive whether the calling subscriber still takes further switching measures after the election (Press keys, hang up handset) has to undertake or not, because at choice of a subscriber connected to a foreign line, the call is complete automatically.

It is also known when calling company management to send the ringing current only once or a few times and then switch it off. Here the call current can be switched off before the called subscriber Had the opportunity to take note of the call.

The present invention is based on the object of an arrangement to create, which in each case the repeated, completely automatic call of a participant connected to a company management, indifferent whether it is a connection between two lines on different lines Participant or a connection between two on the same company management connected participants. It achieves this by following the election the desired branch point at this an asymmetry of the company management is made which on one in the exchange in the bridge to the line lying relay acts in such a way that this relay repeats the automatic Transmission of the Rufstrom over the company line enables, and that at Reporting of the called subscriber to his branching point arranged switching means cancel the unbalance of the line, whereby the relay lying in the bridge deactivated and the automatic call is ended.

The arrangement according to the invention is of course not restricted on systems in which members of a company management communicate with one another can, but can also be used wherever such traffic not possible.

Two exemplary embodiments of the invention are shown in the drawings. One is illustrated in Figs. I to 3 and the second in Fig. Q. until 6. A third exemplary embodiment is briefly explained in section -ILI of the description. The e .-- Ah. i and 4 show the equipment at "two branch points of a company line."

FIGS. 2 and 5 illustrate the company lines in facilities assigned to the exchange.

In FIGS. 3 and 6, the marks for the individual branch points are the company management and the wiring of the facilities to the per se evenly equipped branch points.

I. Embodiment according to FIGS. I to 3 i. The branch point AStß calls and is switched on. The subscriber of the branch point ASt6 picks up his handset. The hook switch contact huJ is closed and then the hook switch contact lrir, II is opened. There is the call circuit: earth, contact ii b6, windings I and II of the relay Spe, hook switch contacts lazt6II, ku.J, impulse contact nsi, connection 7, wire la, contacts 12 ba, 13v, 14 g, i5 p, i6c, winding I of the relay An, -. The relays Sp, and An respond. The relay Spa shorts its winding I on contact i7sp and prepares a holding circuit on contact i, # spf, via its winding III: The relay An is placed in a holding circuit: -) -, contact igkr., Switching arm 2o of the identification selector KW, rest position o the same, contact 2ian, winding II of the relay @ltt, -. The setting of the identification selector KW is prepared at contact 22. The relay A is applied to the wire la via the contact 23an. The relay I is switched on at the contact 24aya, which opens the contact 25i and closes the contact 26i. The - pole of a battery of i2o V is connected via the resistor 27 to the wire lb. The glow lamps, which are located in the branch points on the wire lb, ignite. The B relays in series with the glow lamps respond.

In the exchange, the glow lamp Gla. do not ignite, and therefore the relay bot cannot respond either, since earth is switched off by @Kontal: t 28afa. The excitation circuit for relays B and B, at branch points ASt and ASt, runs as follows: - i2o V, resistor 27, contact 26i, wire lb, branch point ASt "connection 8, glow lamp G18, windings II and I of the relay Bo, earth and branch point ASt7, connection 8, glow lamp Gl7, windings II and I of relay B7, earth. Contacts 1 I bo (ASta) and 29 b7 (ASt7) are opened, and contacts 3o b, (ASts) and 31 b7 (ASt7) are closed The B relays block all branching points that are not in the call state, since contact 29 b7 in ASt7 and the corresponding contacts at branching points ASt until ASts and ASt $ are open.

At the calling branch point ASts the relay Spa remains energized: earth, contact 3o b, winding III of the relay Spe, contacts 18 SA, 32 so, hit EI, nsi, connection 7, wire la, contacts 12 bca, 23 on, relay A, contact 33 "" resistor 34, -. Relay A responds and switches relay h, on: +, contacts 35 w or .I75 x, 36 a, relay V ,, resistor 37, -. The relay V2 switched on via contact 38v cannot respond because it is short-circuited via contacts 36a and 35w or 175x. The circuit via the rotary magnet Dkw of the identification selector KW is prepared at contact 39v.

The calling subscriber -dials his own code number 6 by his number switch from the special one, for sending out the series of bias currents serving finger hole actuated. All participants use their number switch when they call in the same way. However, only those corresponding to your own code number will be used Power surges sent out. After these current surges have been delivered, the Contact slsa the short circuit of the impulse contact nsi. The delivery of the series of advance currents can also be done in other ways, e.g. B. automatically when removing the handset or by pressing the finger disc according to your own number.

In the exchange, the current impulses of the series of preliminary current impulses are transmitted by the impulse receiving relay A to the rotary magnet Dkzu, of the identification selector: +, contacts 22 to, 41 from, 42h, -43a, 39v-, 44p-, 45p, rotary magnet Dkw ,, -. During this series of impulses relay V2 is also energized, since when contact 36a opens, the short-circuit of its windings I and II is canceled: it short-circuits its winding II at contact 46v2 and keeps its armature attracted during the series of impulses. If the switching arm 2o of the identification selector KW has left the normally closed contact, the relay An remains energized, since its winding II is switched on at the contact 47v2. The temporary closings of the contact 48 a that take place during the current impulse do not result in the relay V dropping.

After the end of the series of bias currents, relay A remains energized. The contact 36 a is. . permanently closed. The relay V2 drops out. , Relay An is switched off at contact 47v2, and earth (+) is applied to relay Ba via contact 28 an. This relay is excited by the battery of - 120 V connected via contact 26 i and switches its contacts to the working position. The relay P is energized: +, contacts 49v ,, 5o on, relay P, -. The contact 51 ba is parallel to the contact 4.9 v1, so that the relay P remains energized after the relay V has dropped out. Relay J is kept energized even after contact 24ara has opened via contacts .197c, 52y and 53p, which are in series.

The relay A is switched off at contact 23 can. Contact 36a is opened and contact 48a is closed. The relay l = 'drops out and closes the contact 59v, among other things. Since the contact I2 ba is open and the contact 61 ba is closed, the connection identifier assigned to the calling branch point ASt6 is now applied to the company management.

In FIG. 3, the connection codes assigned to the individual branch points of the company management are compiled. From this it can be seen that a selective current of certain polarity (- or +) and certain duration (short or long) is required to connect each branch point and that the holding windings of the switch relay are either applied to the wire la or to the wire lb.

To connect the calling branch point AStß, a long current surge is required, which at the same time also identifies branch point ASt. The connection relay R6 is held via wire lb, but the relay R7 is held via wire la.

The selection of the connection identifier is made by the identifier selector KW set by the Var current impulse series, the switching arms of which are on the contacts 6. The long - current impulse, which characterizes the two branch points AST and ASt, influences the capacitor resistor arrangements at the branch points via the following circuit: -, contact 6, switching arm 54 of the identification selector KW ,, contacts 58 krs, 59 vi, 6o i, 61 ba., Wire la , at all branch points via the capacitors Ko to earth, namely at the calling branch point ASt, via resistors 65, 66, connections 3, 1 ,. Contacts 67 b, capacitor Koa, earth and at the branch point ASt shown further, via resistors 62, 63, connections 3, 1, contact 64b, capacitor Ko ,, earth. Also at the branch points 5 and 8, the capacitors are connected to two in series, the resistors 65; 66 (ASt,) corresponding resistors are switched on. Connections i and 2 are connected at junction points i to 4. The capacitors are only above the resistor 65, corresponding resistances at the connections 7 and thus on the wire la.

When relay V1 drops out, relay Y is switched on: +, contacts 68p and 69 v1, relay I ', winding I, -. It is held by its winding II and contact 70y. The relay J is switched off at contact 52y. Since a long current surge is required to select the branch point ASt, the relay J must not yet drop out and the contact 6o i in the charging circuit for the capacitors at the branch points must not open. In order to delay its fall, the relay J has switched on the delay relay E: -f-, contact 19 kr =, switching arm 2o, contacts 6, 57 i, -relay E, winding I, -. The relay E switches the capacitor 73 from the charging circuit running via the normally closed contact 72e to a discharging circuit running via the relay J. After the contact 52y is opened, the capacitor 73 is discharged via contact 7.1.e and relay J, during which relay J keeps its armature attracted.

@ 1 after the relay J drops out, a pre-discharge circuit for the capacitors at the branch points is closed via wire la of the company line in order to discharge the capacitors at branch points i to 4. The capacitors at junction points 5 to 8 are also partially discharged. Since the discharge circuit at these junction points, like the charging circuit, runs through two resistors in series, at the junction points AStb and AS't, z. B. via the resistors 65, 66 and 62, 63, these capacitors after interruption of the pre-discharge circuit still have such a charge that the switch relay, z. B. Relay R6 at ASt, and relay R7 at ASt7, can respond when local discharge circuits are closed.

That after discharging the capacitor; 3 relay J dropping out in the exchange closes its contacts 25i, 75i, among other things. and opens contacts 26i, 6o i, 57i. The relay Ba in the switching parts and also the B relays at the branch points remain energized, since the current source = 12o V is still connected to the wire lb via the contact 76e. During the release time of the relay F_, earth is connected to the wire la via the contacts 77e, 75 i, 61 ba and the pre-discharge circuit for all capacitors at the branch points is thereby established.

Relay E drops out, separates earth from wire la at contact 77e and the current source keeping the B relays energized at contact 76e - 120 V from wire lb. The latter is switched through at contact 78e. The relay Ba in the exchange and the B relays at all branch points drop out. The wire la is switched through at contact 12 ba. The capacitors of the branch points are separated from the wire la and placed in local discharge circuits via the normally closed contacts of the B relays. At the calling branch point ASt "the local discharge circuit of the capacitor Ko runs via the contact So b6 and the winding I of the relay R, and at the branch point ASt7 marked by the same elective current (long current surge) via the contact 79 b, and the winding I of the relay R. The relays RB and R respond and switch on their holding windings II by closing the contacts 81r and 82r and also at the branch point ASt5 the holding winding II of the connection relay is connected via the connection 7 with the wire la , while at the branch point ASt and at the branch point ASt, the holding winding II of the R relay via the connection 8 to the wire lb is switched on.

The connection relays of the group of branch points ASts and ASi7 marked by the same selective current (long current impulse) have been connected to the company line in different ways, namely in branch point AS to to wire lb and in branch point ASt to wire la .

Since the branch point ASt is to be switched on, with it the winding II of the relay R is connected to the wire lb, the ungrounded pole (-) of the central battery is on this wire in the exchange on the wire lb via resistor 34., contact 33 ztl , Relay A, contacts 83y, 84w; Accordingly, holding current cannot flow via the winding II of the relay R connected to the wire la , the branch point ASt marked by the same optional current as the branch point ASt. Also at the branch points ASt and ASt, the connection relays R were energized in the discharge circuits of the capacitors. The holding winding of the relay of the branch point ASt5 is according to Fig. 3 on the wire la. This relay cannot hold either and drops out. The holding winding of the connection relay of the branch point ASt $ is just like the one in the calling branch point ASt, on the wire lb. But this relay also drops out; since the holding winding is switched on in a similar way to the one at the branch point AST7, i.e. opposite to that at the branch point ASt. The connections 4, 6 and 5, 8 are connected. The holding current through winding II of the connection relay of the branch point ASt therefore causes a polarity reversal, so that this connection relay drops out. So only the connection relay R remains energized at the branch point ASt. In the holding circuit via the winding II of the relay R, the relay A in the switching center responds and switches on the relay V1 at 36a. Since the relay Y is also energized, the wires io6 and io7 leading to the preselector VW are connected to the contacts io4-a and io5 y. The call relay, not shown, of the preselector responds in the circuit via the choke coil Dr2. The selection is set to a free outgoing trunk.

When the switch-on relay Ra is energized, the speech sets, which are indicated by the microphone Mi, are switched on to the company management. In addition to the circuit via winding II of relay R, there is also the following circuit: +, contact 8gu1, choke coil Drl, contacts ioo y, ioi w, 1 2 ba, wire la, contacts nsi, leu, I, i o8 ra, winding I of the relay S "speech devices, contacts iogb" iioy "connection 8, wire lb, contacts 25i, 78e, 84w, 83 y, relay A, contact 33 7h, resistor 34, -. The relay S, responds. It closes the parallel to the contacts i io r and io8 r, contacts iii s, and 114s ″ separates at contact i I2 s, earth from the winding II of the connection relay R, so that it drops out. At the same time, the unbalance of the speech line produced by the application of the winding 1I of the relay Ra after the branch ASt has been selected is eliminated: At the contact 113s, the winding II of the relay Ba is short-circuited. Contact 32s is also opened.

The connection of the branch point ASt to the company management is completed.

In the exchange remains after opening the contact 69v, the Relay Y via its winding II and contacts 7o y, 68 p energized. Further the relay V1 has the connection to be established by the calling subscriber necessary switchings made.

The transmission of the series of bias currents not only results in the activation of the connection identifier assigned to the calling branch ASt, but also the preparatory activation of the counter Z assigned to it in the exchange, which is connected via the switching arm 103 parallel to the blocking winding of the isolating relay Tr of the gate selector VW is.

The connection of the branch point ASt is described with a long - current impulse acting on the capacitor resistor arrangements, which also the branch point ASt, and that by the different connection the connection relay of these branch points ASts and ASt7 to the company management in cooperation with the connection of the ungrounded one determined by the dialing process Poles of a service battery to the wire lb only connect a branch point ASt, is finally carried out.

By any other stream of elections, it may vary in direction or duration or differ in direction and duration, there are several other junction points, in the exemplary embodiment always a group of two junction points, identified. A long --- current impulse marks the branch points ASt ,, and ASts, a short one - Power surge the branch points ASt. and ASt3 and-a short + -current impulse the branch points ASt, and ASt, Always the final connection - the specific junction point characterized in that the connection relays of the respective -marked branching points themselves switch on in different ways to the company management and only the switch-on relay of the junction to be switched on remains energized, as only a suitable one for this Holding circuit is established in the exchange.

2. Connection of the branch point ASt, with the A # b: branch point ASt, the subscriber of the branch point ASt wants to speak to the subscriber of the branch point ASt. He first dials the code number of his own line: These number current impulses act not only on group and line dialers but also on the identification dialer KW. to the company management. After this has been set according to the code number of the own line, the set group and line selectors are enabled. The completion and maintenance of the connection is carried out exclusively by the institutions assigned to the company management.

The energized by energizing of the relay to relay P p at the contact 45, the rotary magnet of the identification Dkwl selector KW off, and for p via the contact 113 to the rotary magnet D * w2 under the Evnfiuß of the latching contact 43 a. brought. The circuit for the rotary magnet Dkw2 is prepared at the contact rigg by the relay G. This relay was switched on after the second response of the relay V1: +, contacts 114A ii 5 v1, 116Y, 11714 relay G, -.

Due to the number current impulses to be sent out by the calling station, the group dialer and the line selector in the exchange are set not only by means of the contact io4a, but also by means of the contact. 43 a the identification selector KW2 acting as a follower. The code number of the company management, at which the branch points ASta and ASt7 are located, is 24.22. The follower must therefore be set by four series of current impulses each with 2, 4, z and 2 current impulses. If any of these four series of current impulses consists of a different number of current impulses, the identification selector K W2 is switched off immediately, since it is then determined that this series of current impulses does not have the appropriate value for establishing a connection with a branch point on the calling company line and that a Connection with a foreign connection line is under construction. With each number current impulse series which acts on the identification selector KW, its switching arms i2o, 121 and 122 are adjusted. Only from the row of contacts swept by the switching arm i2o are all the contacts o to 18 shown, while of the contacts over which the switching arms 12r, 1 @ 2 are moved, only the contacts ii to 18 are shown, since switching operations via the contacts i to lo , which play a role in the connections to be described, are not initiated.

The switching arms are set to selector contact 2 by the first series of impulses. After the relay V2, which is energized during each current impulse, has dropped, the identification relay Krl is energized: +, contacts 123ab, 124v2, switching arm i2o, selector contact 2, winding I of the relay Krl, -. The relay Krz is in a holding circuit: -i-, contacts 125 , 126 krl, winding II of the relay Krl, resistor 127, -. It opens at contact 128 kr, the connection of selector contacts 5 and 6 and applies winding I of identification relay Kr to the latter via its contact i29krl, and contact 130 krl, which is in series with winding I of identification relay Kr, is opened.

The selector is set to the identification contact 6 by the second series of current impulses, which consists of four current impulses. After closing the contact i? -4v. speaks (read identification relay Kr "and switches to a holding circuit via its contact 13o kr2 and its winding II. It opens the connection of selector contacts 7 and 8 at contact 131 kr and applies the holding winding II to the latter via contact 1 32 kr2 of the identification relay Krl.

The third series of impulses brings the selector to the identification contact B. After the contact 124f12 is closed, the identification relay Krl is brought to drop because its holding winding 1I is short-circuited. Located at the lower end of winding -f on i25, and i26 krl. After the contact 124.v2 is closed, - [- is also at the upper end of the winding over 1:23 from, 12 ¢ v2, 120, 8, 132 kr2. Contact 126 kr1 is opened and contact 13o kr1 is closed.

The last series of impulses to identify one's own line controls the identification selector KW2 to the selector contact i o. As the identification relay K.r-3 with its winding .1 via the contacts 13ökrl and i34kr2 in series is on this selector contact, it responds after the control relay h2 drops out. In order to is the indicator that a connection with a branch point of the calling Company management is intended to be established.

The relay Kr3 is placed in a holding circuit via its winding 1I and the contact 135 krg. It separates the connection of the selector contacts 9 and ii or 14 and 15 by opening the contacts 136 kr and 137 krs. An excitation circuit for relay H is prepared at contact 138 kr3 and wire 107 is cut at contact 139kr3. This initiates the triggering of the selected selector of the exchange, since the loop that keeps the bridge relay energized at a downstream point on the connection path is opened via the choke coil Dr ...

If any of the series of current impulses does not have the appropriate value for identifying its own line, the switching arms of the identification selector are not set successively to the # identification contacts 2, 6, 8 and io. If, for example, the second series of current impulses consisted of two and not four current impulses, the switching arm i 2o was on the selector contact after the same, 4. It then responds to the relay Ab and switches via its contact 104ab and the winding II into a holding circuit dependent on contact 14.1 v1 of the release delay relay hl. The contact 41 ab in the circuit of the rotary magnet Dkw2 is opened and this rotary magnet is thus withdrawn from the influence of further current surges. These therefore act exclusively on the number surge receiver, the exchange.

To select the desired branch point ASt, the calling branch point sends a last series of current impulses consisting of seven current impulses, through which the switching arms of the identification selector are set to contact 17. This defines the connection identifier for the desired junction point ASt, which, as can be seen from FIG. 3, consists of a long current surge. The desired branch point therefore has the same connection identifier as the calling branch point ASt. When it is triggered, the relay Krs has the identification selector KW, which cooperates with the connection of the calling branch point ASta. separated by opening the Kontaktds 58hys and applied via the contact 142 hrg the switching arm 122 of the identification selector KW, preparatory. The relay H responds to: -, relay H, contacts z38 hrs, 143 v2, switching arm i2 @ i, selector contact i7, contact.i44ba, + and is connected to contact 2o2 h in a holding circuit dependent on contact 17171a. The contact i 17 h the relay G is turned off. Relay J is energized: -E-, contacts 1q.5 w, 1461a, relay J, resistor i98, -and applies 12o V to wire lb via contact 26i, -. The B relays respond at all branch points and connect the capacitor resistor arrangements to the wire la ,, for example relays B, and B., At branch points ASts and ASt7. It is also excited the relay Ba in the exchange, which by opening the contact 144bd cancels the short circuit of the winding 1I of the relay U1, which responds. The opening of the contact 25i causes the relay A to drop out. The relay V drops out and applies to the contact 59v1 the switching arm 122 of the identification selector KW, which is on the selector contact 17 and is thereby connected to the wire la. The capacitors, which are connected to the connections 7 and thus to the wire la via one or two resistors in series, are charged at all branch points. At the desired branch point ASt7, this charging circuit runs through the resistors 62, 63, the AngchlüSse 3, 1, the contact 64 b7 and the capacitor 1 (.o7 to earth.

In the calling branch point ASt, 1, the excitation of the relay Ba also results in the opening of the speech circuit, since the contact 1o9 b is opened. The relay S, however, holds on to its winding II, which is connected to the wire lb via the contact 1q.7 b. After relay h1 has dropped out, relay W is also switched on in the exchange: -r-, contacts 68p, 69v,., 148h, relay W, -. Relay J is switched off at contact 145 w. As to connect the branch point ASt? A long current surge is required, relay J must not drop out after contact 145 w has opened. Its fall is again delayed by the discharge of the capacitor 73 through its winding. The relay E, which controls the charging and also the discharging circuit of the capacitor 73, is switched on via its winding II: -E-, contacts 123ab, 124v2, switching arm 12o and selector contact 17 of the identification selector I (W2, contact 149 i, winding II of relay E. It opens the charging circuit of the capacitor 73 at contact 72e and places it at contact 74e parallel to relay J. After the capacitor 73 is discharged, relay J drops out, opens its contacts 6o i, 149 i and closes its contact 75 i. The charging circuit via wire la is interrupted. The relay E is switched off. Since it has delayed armature drop, the contact 77 e , among other things, is still closed for a short time Relay B is kept energized at the branch points - 12o V, after contact 25 i has been closed via contact 76 e , relay E is still connected to wire lb during the release time After the relay E drops out, the power source is switched off - 12o V from wire lb at contact 76 e and the pre-discharge circuit is interrupted via wire la at contact 77 e.

If -12o V is disconnected from wire lb, the B relays in the branch points drop out. The drop-out of relay B "of the calling branch point is delayed because its winding 1 is short-circuited at contact 113. Relay Ba in the exchange drops out. Wires la and [b are now at contacts 12 ba and 78 e, respectively switched through.

As already described, speak in the 'after the B relay has dropped out Only the closed discharge circuits of the capacitors at the branch points Connection relay at branch points ASt5 to ASt, because the capacitors of the Branch points AS t until ASt4 are discharged and switch on their holding windings. At the calling branch point ASt, there is earth from winding II of relay Ra at contact i i 2 s, disconnected. This relay cannot hold.

Of the connection relays at branch points 5, 7 and 8, only the connection relay R7 of the desired branch point can keep its armature attracted. The winding II of this connection relay R7 is on the wire la. If the branch-off point Ast, which is also characterized by a long current surge, was not in the call state, then the winding II of its connection relay R6 would be connected to the wire 1b. To keep the relay R energized, and thus for the final connection of the branch point ASt, it is necessary to connect the ungrounded pole of a service battery to the wire la and earth to the wire lb in the exchange. These switchings are carried out as follows: The switching arm 121 of the identification selector K W2 is on contact i7. After the relay Ba has responded and the short circuit in winding II of the relay U at contact 144ba has been eliminated, this relay is energized. The relay U2 is switched on at 89u1, which in turn establishes a holding circuit via the winding I of the relay U1 at the contact 95'12. With regard to the calling branch point ASt already connected to the company management, switching the --Pole from wire lb to wire la and the earth from wire la to wire lb cannot be carried out, since then the energized relay S, on the branch point ASt, would be repolarized, which would result in its anchor drop. The contacts riis "and 114 ss would open, and the branch point ASt would be switched off. The unearthed pole of a battery is therefore connected to wire la and earth to wire lb. The direction of current changes over the company line so not one.

Switching from -6o V on wire lb to -r- 6o V on wire la takes place in two stages. First, + 6o V is applied via the high resistance 9: I -and the contact 92't1 to the wire la, as well as earth via the high resistance 93 and the contact gi ztl. This is followed by a separation of earth from wire la at contact 89'1l and -6o V from wire lb at contact 33'1- If the delay relay U2 has also picked up its armature, then -f- 6o V is above the low resistance 98 and the contact 99'12 on the wire la and earth via the low resistance 96 and the. Contact 92 z12 on wire lb. Fetzt microphone power flows through the company management at full strength.

The relay W which brings about the termination of the selection current surge has, when it is energized, canceled the short circuit of the windings I and II of the differential relay X by opening the contacts ioi w and 8.4w. The winding 11 of the relay R, the branch point ASt, is therefore in the following holding circuit: + 6o V, resistor 98, contact 99't2, choke coil Drl, contact iooy, winding I of the relay X, contact 12 ba, wire la, branch point ASt "Connections 7, 5, winding II of relay R" Connections 6, q., Contacts 82 r ,, I02 SV earth. After relay B has dropped out at the calling branch point, the following circuit is established: from wire la via connection 7, contacts .nsi, huaI, ii4S "relay SE, winding I, microphone illi, contacts pulled b, III s, connection 8, wire lb, contacts 25 i, 78 e, winding II of relay X, contact 83 y, relay A, contact 97't2, resistor 96, earth. The relay A responds. Furthermore, however, the differential relay X is excited by the branching point called ASt by connecting the winding II of the relay R to the wire la , the differential relay X, because stronger current flows through its winding I than through the winding II. This enables the automatic periodic call to the branch point ASt7.

Contact 175 x in the circuit of relay V1 is opened. Since the contact 35 w is also open, the closing of the contact 36a by the responsive bridge relay A cannot be followed by an energization of the relay V1, whereby a premature disconnection of the ringing current by switching off the relay W is avoided.

At contact i5iw, after contact i52 ba has closed, a circuit is closed via winding l of relay Ab . The relay Ab disconnects the holding circuits of the excited identification relays Kr and KY3 at contact i "25 ab . The relay Kr1 has already dropped out during the selection process.

Relay W has the circuit of the call relay via contact 150w Rr closed. The relay Rr speaks, for example, every 5 seconds when switched on des --Pole via the time switch 5 ".

The winding II of the connection relay R, the selected branch point ASt, is on the wire la. The alarm clock of this junction is connected to the wire lb; Calling current is always sent from the exchange via the wire that does not carry the holding current for the energized connection relay. The connection of the ringing current to one or the other wire is determined by the same relays U1, U2 that cause the connection of the ungrounded pole of a central battery to wire la or lb. The relays U1 and U2 are excited when one of the branch points AStI, ASt3, ASt5 or AST is selected. If they are energized, the contact 1522G1 is open and thus a short circuit of the winding I of the relay X during the ringing when the contact 153m is closed is avoided. The contact 154112 is open, so that accordingly the alternating current source cannot be applied to the wire lca via the contact 155 rr. By closing the contact 156u2 the short circuit of the winding II of the relay X and by closing the contact 157u2 the application of the ringing current source to the wire lb is prepared. When the relay Rr is below the. Influence of the 5 "switch responds, it completes the short circuit of the winding II of the relay X at contact 158 rr and applies the alternating current source to the wire lb at contact 159 rr activated: ringing current source, contacts 159 rr, 157 u " 78 e, 25 i, wire lb, connections 8, 9y contact 22o r7, alarm clock, earth.

This is due to the asymmetry of the company's management, which is part of the Branch point ASt, which was established, also prevents the differential relay X from being energized by opening the contact 16o x a premature excitation of the signal relay 1V1.

If the subscriber of the called branching point ASt7 answers. winding I of relay S7 is placed between wires la and lb: wire la, contacts nsi, hu7I, 161r7, winding I of relay S7, speech sets, contacts 162b7, 163r7, connection 8, wire lb. The relay S; responds, closes contacts 164s and 165s7 lying parallel to contacts 161 r7 and 163r7. It also opens the holding circuit via winding 1I of relay R7 at contact 102 s7. The unbalance of the line created after the selection at this branch point is thus eliminated.

The result is that the differential relay X drops out in the exchange and the contact 175 _x closes. The relay T can now respond: -E-, contacts 175x, 36a, relay V1, resistor 37, -. The contact 16o x is also closed. After energizing the relay hl, it responds to the relay F1: -E-, contacts 141 v1, 173 w, winding II of the relay PI, -. The relay M is also excited: Contacts 141 v1, 166w, 16o x, relay IVI, - By opening contact 167m and closing contact 168m, + is switched on via contact 169 c to switching arm 103 and thereby to counter Z6 of the calling branch point ASt6 created. The counter Z0 responds and registers the connection established with a subscriber of the calling company line. At contact 171 m the holding circuit is opened via relay H, which drops out and at contact 11712 the circuit of relay G closes, which responds. By opening the contact 88g the relay, U2 is switched off, drops out and switches off the relay U1 at contact 95 u2. The drop in relays U2 and U1 results in the disconnection of the battery, the --.- pole of which is ungrounded, and the connection of the normal operating battery with an ungrounded - pole. Switching from + 6o V to earth on wire la and from earth to - 6o V on wire lb takes place in two stages. First, the low resistances 96 and 98 are switched off by opening the contacts 97 u2 and 99 u2. Then the contacts 33 u1, 89 u1 are closed, whereby - 6o V is applied to the wire lb and earth to the wire la , and then the contacts 91 u1 and 92 zil open and thereby the final disconnection of + 6o V from the vein la and earth from the vein lb.

Even with this switchover, there is no change in the direction of the current via the cores la and lb of the company line.

The drop in relay H also causes relay W to be switched off by opening contact 148h. After contact 69 v1 has opened, relay W drops out. The windings of the differential relay X are short-circuited at contacts 1o1 w and 84w. Contact 173w in the circuit of winding II of the relay. P1 is opened. The relay P1 is held .aber via the parallel contact 174h and, by keeping the contact 175h open, prevents the preselector VW from starting up after the contact 275w is closed. At contact 1171G, winding I of relay G is switched on.

If, at the end of the connection, the subscribers at both branch points ASto and ASt7 hang up their handsets, the feeder bridge relay A in the exchange drops out. The release delay relay hl is short-circuited at contact 48 ca, which, among other things, interrupts the holding circuits of relays Ab and P1 by opening contact 141 v1. The Relaisjl drops quickly and closes a circuit at contact 44h for the rotary magnet D @ ktv2 of the identification selector KW,: -, rotary magnet Dkw2, contacts 1 13 p, 44 A, 40 v "winding III of the relay Ab, head contact 177 kkw2, breaker RU, -y-. The relay Ab is kept excited by the current flowing through its winding III and prevents the relay P from dropping during the triggering movement of the identification selector KW , since the contact 176 remains closed. When the identification selector KW reaches the rest position , the head koutal, t-1771, hw, is open, the relay Ab drops out and interrupts the circuit of relay P at contact 176 ab. It also prepares the tripping circuit for: the identification selector KTVi at contact r78 ab Drop of relay P closed and, since relay G still keeps its contact 179g open, runs as follows: -, rotary magnet Dkwi, contacts 45 p, 44p1, 40v "178 ab, relay G, winding 1I, head contact 18o kkwi, breaker RU, - [-. During the tripping movement, the relay G remains energized via its winding 1I. If the identification selector KLVi reaches the rest position, the head contact 18o is slightly open, the relay G drops out.

When relay P drops out, relay Y is also switched off at contact 68p, that puts its contacts back in the rest position. The circuit is made at contact 114p Opened via winding I of relay G.

3. Selection of the branch point ASt "via the line selector LW When the line selector is set to the connection of the branch point ASt and the company line is free, the test relay Plw and the occupancy relay C are activated in the test circuit. The latter is connected to a holding circuit via its contact 189c. Es switches on the winding I of the relay P1 to the switching arm 56 of the identification selector K97 at contact 19o c, and the isolating relay Tr switches on at contact Zoo c, which separates the call bridge from wires 1o6 and 107 in a known manner. The drive magnet Dkwi is switched on at contact 192 c. The identification selector is automatically advanced until relay P1 responds via its switch position 6 and contact 44p1 opens.

Relays H and A are switched on: -, relay PI, contacts 193111, 194 h, r-, and -, resistor 34, contact 33 11i, relay A, contacts 2I2 y, 195p-1, I96 ba, +, earth. The relay V, is switched on via the contacts 36 d and 35 w or 175 x , which energizes the relay P via contact 49 v1. The relay 1 is energized: -1 -, contacts 145w, 1,461c, relay J, resistor 198, -. In the manner already described, -12o V is applied to the -wires lb via contact 26i. The B relays at all branch points and the relay Ba in the exchange respond. At contact 196 ba the circuit is opened via relay A, relay A and thus also relay h1 drop out.

At the branch points, the B relays have the capacitor resistor arrangements, which are all influenced by the selected current assigned to the selected branch point ASt, a long current surge, which also serves to select the branch point ASt, to the wire la. switched on, for example at the branch point ASt, the capacitor Ko, via contact 67 b @ and at the branch point ASt, the capacitor Ko, via contact 64 b ,. Since the switching arm 54 of the identification selector KW is on the contact 6, after the contact 59v1 is closed - applied to the wire la . The capacitors of all branch points are charged as described in section 1. Since contact 1481c is closed, relay W is excited via contact 69 v1, which opens the circuit of relay J at contact 145 w. Since a long current surge is required to select the junction #ASto and also the junction ASt, the fall of the relay J is again delayed by the fact that the relay E, which is excited via the contact 57 i and the switching arm 2o of the identification selector KW, is opened by opening the Contact 72 e and closing of contact 74 e, the capacitor 73 in parallel with the relay J puts. In the discharge circuit of the capacitor 73, the relay J still remains energized. After the capacitor 73 has discharged, it drops out, opens the contacts 6o i, 26i, 57i and closes the contacts 75 i, 25 i; - During the release time of relay E, 12o V is still applied to wire lb via contact 76 e. During this time, the pre-discharge circuit for the capacitors at the branch points is closed again via the contacts 77 e, 75 i, 61 bca. After relay E has occurred, - 120 V is switched off from wire lb at contact 76 e, this wire is switched through and, at the same time, the pre-discharge circuit at contact 77 e is interrupted. After the relay Ba has dropped out, contact 1 2 ba. also the vein la switched through.

The capacitors of the branch points ASti to ASt are now discharged. After the B relay has dropped out, speak to the feeder. set AStr, to ASt $ the R relays in the local discharge circuits of the capacitors and switch their holding windings 1I a.

The final connection of one of the two branching points ASt and ASt "whose connection relays have their windings 1I differently connected to the company line, the one to the wire la, the other to the wire lb", is again dependent on which Wire la or lb the originally earthed pole of a power source is connected.

In the switch position 6, the relay Ui cannot respond via the switch arm 55 of the identification selector KW. Accordingly, relay U2, which is directly dependent on it, also remains in the rest position. Since relay W is energized, as already described, it is - 6o V. Across resistor 34, contact 33 ih, relay A, contact 83 y (relay Y has been energized in the meantime), winding II of relay X, contacts 78 e, 25 i on wire lb so that relay R can keep its armature attracted. The relay R, the branch point ASt, drops because earth is applied to the wire la in the exchange. For the same reason, the R = relay of the branch point ASt5 also drops out.

The R relay of the branch point ASte, its winding II on the wire Ib lies, falls, since, as mentioned earlier, polarization is reversed, likewise away-.

By connecting the winding II of the relay Ra to the wire lb, a basic symmetry of the company line is established at the selected branch point, so that not only the relay A but also the differential relay X responds via the holding circuit for the relay R6. This enables the automatic periodic call to the branch point ASt. @ By opening the contact 175x the excitation of the relay T, is prevented. The call relay Rr is switched on at the contact i 5o w, which is excited every 5 seconds under the influence of the timer 5 ", for example, and applies call current to the wire la , which does not carry the holding current for the connection relay. The alarm clock rings in the branch point ASta.

If the called branching point ASt responds, the relay R, closes the contacts iii so, 114s, and removes the basic symmetry of the company line by disconnecting the earth from winding II of the relay RE at contact i 12 s5. In the exchange relay X can therefore no longer keep its armature attracted, but drops out, closes the circuit of relay V1 at contact 175 x , which responds. Relay M is energized:. +, contacts 141v1, 166w, i6ox, relay 111, The holding circuit of relay H is opened at 171 m, and when contact 69v is only opened after contact 141 v1 has been closed, relay W is switched off and drops out. Call relay Ry is switched off, and windings I. and II of the differential relay X are short-circuited at the contacts ioi w and 84w.

The drop in relay H also causes relay G to be energized via its winding I: +, contacts-ii4p, iisv1, 116y, i 17h , winding I of relay G, -. The relay G closes the contact i 18 g located parallel to the contact 1 1 5 v1, opens the contact 179 g and thereby removes the short circuit of its winding II. The contact 181 g in the occupancy circuit is opened and the short circuit of the occupancy relay C is prepared at contact 202 g.

If at the end of the connection the subscriber of the branch point ASt hangs up his receiver, the relays A, Tll and P drop out. The circuit for the rotary solenoid Dhwl of the identification selector KW is closed. As described earlier, it runs via winding II of relay G. Relay C is short-circuited and drops out, since contacts i 84p, 183 a, 182 an and? -O2 g are closed. The circuits of the relays P1, C and Plw are opened at the contacts igo c and i89 c.

II. Exemplary embodiment according to FIGS. 4 to 6 i. The branch point ASt15 calls and is switched on. The subscriber at the branch point AStlr picks up his handset. The hook changeover switch contact hit "I is closed, the hook changeover switch contact hu15II is opened. The call button Ta15 is pressed; there is the following call circuit-. +, Button Tal", contacts 15 b15, 16sp15, relay T15, hook changeover contact hu15 I, contact 17 Y15, connection 8, wire lal, contacts 18w1, ig y1, 2o from "21 n, winding I of relay P2, winding I of relay on" -.

The relays Anal in the exchange and T15 in the branch point ASt15 respond. Relay P2 cannot respond due to the high resistance of relay T15. The relay An, switches on the relay J1:.-F- , contacts 22 hylg, 23 to "relay J1, resistor 24, -. The relay Ji disconnects the wire lbl from the transmission at contact 25 il and places it on it - 12o V via contact 26i1 and resistor 27. Ignite the glow lamps at all branch points and ignite the glow lamp, Gla in the exchange. All B relays respond, including relay Ba in the exchange and at the branches ASt15 and AStl shown "Relays B15 and B16 in the following way: - i2o V, resistor 27, contact 2611, wire lbl, branch point ASt15, connection 9, glow lamp Gll5, relay B15, Wick-Jung I, contacts 33 sp, 5, 34b15 (40t15 is open), 35s15, 3 6s13, earth, and at the branch point AStis: connection 9, glow lamp Gl, o, relay Blo, winding I, contacts 28 spls, 29 blo or 3ö tlE, 31 s, c, 32 s18 , earth .

-At all non-calling branch points, the responding B relay prevents the closing of the call circuit, so at the branch point ASt "by opening the contact 37 b" lying in series with the Talg key.

At the calling branch point ASt, 5 is via the contacts 38 4s and 39b15 earth applied to the relay T15, so that this also after opening the contact i 5b, 5 still remains excited. After opening the contact 34b ″ speaks because the contact 4o t, 5 is open, the relay Sp, 5 in series with the winding l of the relay B15. It opens contact 16spls and closes contact 41 sp, 5.

The branch point AStl belongs, as can be seen from FIG. 6, to group I. The connections 13 and 14 are connected to it. It is therefore temporarily, during the release time of the relay T15, the direct connection of earth via the contacts 39 b15, 38 45, 41 sp15, connections 14, 13, contacts hu, 5 I, 17r15, connection 8 to the wire la , and thus to the call circuit. In the exchange, this ground connection, which forms the indicator for group I of the branch points, activates the relay P2, switches on at its contact 42p2 into a holding circuit which runs over its winding II and is prepared at contact 43 bal. By opening the contact 44p2 and closing the contact 45p2, the first preparation of the circuit containing the counter Z15 of the calling branch point AStl takes place.

After opening the contact 16 sp, 5 in the branch point, the relay Th drops out, among other things, the contact 38t15 is opened. In the exchange, the relay An, drops out. The relay W, is excited: - @ -, contacts 46krls, 47 anal, 48 bal, relay W ,, -. It switches off the windings I of the relays Aal and P2 of the wire la at contact i 8 w. Contacts 49w, and 5o w, are opened. W via the contact 5i, the connection dis relay Ka to the wire la is, and w via the contact 52, the connection of the relay Kb lb in the vein prepared. It also switches the relay Y, on: +, contacts 46kr, s, 47 to "48 bal, 53w" 72 ka, 73 kb, 74 from "relay Y1, -. The relay Y, closes and at the same time also the relay W , via contacts 75: Y1 and 765b, into a holding circuit, it closes a new holding circuit at contact 137y via winding II of relay P. ha before. At the contacts 77Y, and 78y1 the closure of the supply and surge bridge for the calling party to the branching point AStlS is prepared.

By opening the contact 23, the relay 1 ,. switched off. It drops off and separates - i2o V from the wire lb. The relay Bal drops out. The wire la, is connected to the contact 61 ba, and the wire lb, to the contacts 25 i ,, 58 e. The B relays drop out in the branch points.

Relay Sp, 5 remains energized at the calling branch point: earth, contacts 36s "', 35s15, relay SplS, contact 54sp, 5, resistor 5.5, contacts 56b15, 57 r1s, connection 9, wire lbl, contacts 254, 58e" 52w1 , Relay 1 (b, -. Relay Kb cannot respond in this circuit. Winding II of relay R, 5 of branch point ASt, S is connected to wire la, and is in series with relay Ka in the following circuit: Earth, contacts 59 b15, 6o spl5, connections 4, 5, winding II of relay R15, connections 7, 6, 8, wire lal, contacts 61 bal, 51 w1, relay ha, -. Both relays R15 and Ka respond. In the exchange it is thus established that the branching point belongs to group III.

Relay R15 opens the circuit for relay Sp, S at contact 57r15, which drops out and opens contact 6ospl5. The relay S, 5 is connected in series with the winding II of the relay R, 5 via the contact 62r15 and responds. It short-circuits relay R15 at contact 63 s15 '. As long as the relay 1i'15 still keeps its armature attracted, earth is connected to wire lb, and causes the relay Kb, which determines that branch point ASt15 to belong to group VI, to be energized in the following way: earth, contact 68s "", terminals 12, 11, contact 69r15, connections ok, 9, wire lb ,, contacts 25 a "58 e1, 52 w ,, relay Kb, -.

Relay Ka is energized first and then relay Kb. As a result, relay Ha is energized: -f-, contacts 70 ka, 7 1 kb, relay Ha, -. It has switched itself into a holding circuit via its contact 791a5. The connection of the counter assigned to the calling branch point AStl "is also prepared at contact 82lia. The relays Ha, Ka, hb have other contacts that do not serve to connect the counter Z15: 80 ha, 8171a, 8311a, 84 ka, 85 kg, 86 hb, 87 kb open or closed.

When the branch point ASt, S is called, the relays Ka and Kb excited. The differential relay N therefore drops after it has passed through the flow of current its in series with that Holding winding II of the relay Ka lying Winding I has responded, again when the circuit has its winding II and the winding II of the relay Kb at contact 89, kb is closed. In the meter connection device the contacts go ia, 9: i ia, 92 lt, 9: 3 ya are only temporarily in the Working position transferred. The counter Z15 is during the connection via the contacts 82ha, 90n, 45p, switched on.

By the described control of the group detection devices consisting of the relays P2, Ka, Kb, Ha and N in the exchange by the identification of the groups to which the calling branch ASt "belongs, it has been established that this branch belongs to groups I, III and VI is assigned.

When the relay Ka is energized, the holding circuit of the relay Iah, which is equipped with delayed armature drop-out, is opened at contact 72 ha. If the relay W1 drops out, since the relay R15 in the branch point ASt has also dropped out and its contact 57r15 closed, the microphone feed circuit is closed. The relay S1. ' keeps its armature attracted for some time due to its drop-out delay and therefore contacts 64s15 and 65s "5 are still closed. 61 bal, wire lal, connection 8, contacts 17r15 ', hui "I, 65s, 5', speech devices (indicated by microphone Ni), impulse contact nsi15, relay S15, contacts 64s1 ;; , 56b15, 57r, 5, connection g, wire lbl, contacts 25 il, 58 ei, '5o w1, 78y1, 96w2, 97 "c3, relay Al, -.

In the branch point ASt15 the relay S "responds, closes its contacts 66s1 ,, and 67s15 lying parallel to contacts 6q.5'15 and 65s15. It also opens at contact 35s, the short circuit of winding II of relay S15 ', but that does not respond again at the moment because the contact 545'p15 is open and the Glow lamp GI "has not ignited.

In the exchange, the relay Al responds. It opens the contact 98 a1 and closes. the contact 99a1 so that the relay h5 'responds: +, contacts ggal, ioozu2 or 236x1, relay V5', resistor ioi, -. The relay V3 prepares the establishment of a connection, inter alia, in that it brings the rotary magnet Dkw of the identification selector KW under the influence of the impulse contact 104a1 by opening the contact io2v and closing the contact 103 v3. Further contact transfers carried out by the relay V3 emerge from the further description. At contact 105 cal isf the inductor Dr4 is connected to the wires i06 and 107 , which lead to the selection VW. In a known manner, the call relay, not shown, of the preselector VW responds and causes the preselector to be set to a free outgoing line. Parallel to the illustrated locking and holding winding of the relay Trl, the counter Z15 of the calling branch point ASt15 is via the contacts i o8 w2, i og cl and 82 ha, 90n, 45p2 in the same way as the counter of a single line subscriber.

2. Connection of the branch-off point ASt with the branch-off point AStlc The subscriber of the branch-off point ASt sends out the series of current impulses corresponding to the connection number 2q.226 of the branch-off point ASt, r. The first four rows of Stronis are used to indicate that there is a connection with a participant in the company's own management. After this series of rushes takes effect, there is a switchover in the exchange, which has the consequence that the numbered surge receivers set are released and the connection is only completed by facilities on the company management. For this purpose, the series of numbered current impulses also act on a follower on the company management, namely on the identification selector KW.

The rush current series sent out by the calling subscriber are passed on by the relay A1 by means of the contact 105 a to the rush current input devices of the group and line selectors in the exchange. The setting also takes place at the same time. of the identification selector KW in that the rotary solenoid Dkw is switched on every time the relay A1 drops out: -f-, contacts i ioyl, iii abl, 104a1, 103v3, rotary solenoid Dkw, -. When the first current impulse takes effect and the contact 98a closes, the relay V4 is energized, since the short-circuit of its windings I and II at the contact ggal is canceled. is: +, contacts 1 i 2v5 ', windings I and II of relay V4, contacts i o0 w2 or 236x1, 98a.1, resistance ioi, -. The relay V4 short-circuits its winding II at contact 113 v4 and thus remains energized during the series of impulses. A drop in relay V3 due to the contact 98a temporarily closing with each number current surge to be transmitted does not take place with regard to the drop-out delay of this relay. The relay V4 opens, among other things, its contact 114v4 and thereby prevents the identification relay to be controlled via the switching arm 115 from being influenced during each setting movement of the identification selector.

After completion of the first series of strokes, the identification relay Kr "is excited via its winding I: -E-, contacts ii6y1, ii7abl, iiSa1, 114v4, switching arm 115, contact 2, winding I of the identification relay Kr", -. The relay Kr11 switches itself into a holding circuit via its winding la: -E-, contact iigy1, winding h of relay Kr11, contacts 12o kr13, z2i hr11, -. It opens the connection between selector contacts 5 and 6 at contact i22 kr11 and connects winding I of the identification relay K% to contact 6 via contact 124kr11. The contact 123 ky11, which is in series with the winding I of the relay Kr ", is opened.

The identification selector KW is brought to contact 6 by the second series of current impulses consisting of four current impulses. After the contact 114'U4 is closed, the identification relay Kr12 responds by current flowing through its winding I. It switches to its contact 1 25 kr "via its winding da in a holding circuit, disconnects the connections between the selector contacts 7, 8 and g, io at contacts 126 hr12 and 127 kr12, and switches the reverse winding II via its contact 128 kr12 of the identification relay Kr11 to the selector contact 8: in and by closing the contact 129 k1-12 prepares the signal for the identification relay Kr "via the selector contact io.

By the third, consisting of two current impulses series of current impulses, the switching. arms of the identification selector KW brought to the eighth contact. After the contact 114v4 is closed, a circuit is closed via the counter winding II of the relay Kr11: -f-, contacts 116y1, ii7abl, ii 8a.1, 114V4, switching arm 115, contacts 8, i28kr12, winding II of the relay Kr ", contacts i 2o kr 1s, i 2 i kr ", ---. The identification relay Kr "drops out. It switches off its two windings 11 and 1a at the contact z2i k7-11 and applies the winding of the identification relay Kr" to the selector contact io at the contact 123 kr ".

If the fourth series of impulses (two impulses) has the switching arms of the If the voter is switched further, the relay Kr "responds. It closes its contact 13o kr13 and thus a holding circuit across its winding h. At contact 131 kr " the connection of the selector contacts 14 and 15 is interrupted and at contact 132 kr13 prepared the connection of relay E1 to selector contacts 15 to 18. The purpose of the relay El will be explained later.

Since the four rush rows identify a connection with a subscriber on the calling company line, the number rush receiver (group dialer and line selector) of the exchange set in series by the same rush series is triggered. The identification relay Kr13 that came into effect last opens for this purpose -at contact 133 kr "the speech wire IO7.

Will establish a connection with a connected to a foreign line Participants established, it is through the first of those series of current impulses, which does not correspond to the connection number of the calling company line, the identification dialer K rh not set to a tag contact. It then takes place immediately Deactivation of the identification selector. It is prevented that this through the further current surges is stopped.

For example, if the first series of impulses consists not of two, but of three current impulses, then after the contact i 14v4 is closed, the switching arm 115 is on contact 5. The cut-off relay Abt responds and moves into a via contacts 13 ty, and 135ab Holding circuit. At contact i 17 , it separates the + pole from your switching arm i 15.

After choosing their own company management, the calling subscriber sends nor one of the connection numbers of the desired subscriber ASi1, corresponding Current impulse series of six current impulses, which the switching arms of the identification selector K TV sets to contacts 16. In this electoral position there will be a later Excitation of relay E1. This will have an effect on the capacitor resistor arrangements at the branch points by an elective current consisting of a long surge certain polarity secured.

The last row of current impulses corresponding to the connection number of the desired branch point determines not only the duration of the elective current influencing the capacitor resistor arrangements at the branch points, but also its polarity. As can be seen from FIG. 6, the connection of is required to select the branch point A, St1. The connection of -or -E- 72 V to the lcal wire is different from this; depends on whether the relay on is energized or not, because - = - 72 V is only switched on when the normally closed contact r37 is on and + 72 V only when the normally open contact 139 is on.

Since the relay Kria is energized, the relay Kr "and the relay An, to: -j--, contact II 9 y1, relay l (rll, winding h, contacts 14okr", 141v4, Iqzabl, switching arm I43, contact 16 , Winding II of the relay Ani, -. The contact 137d14 is opened "and the contact 139 a" 1 is closed. The connection of + to influence the capacitor resistor arrangements at the branch points is thereby ensured.

The contact 145 krll lying parallel to the contact 141 v4 is closed. The closure of the contact 146 krll in series with the winding I of the relay Ab is of no significance at the moment. Since contact 148 krl is also closed, relay II is switched on via contact 147 kril, which opens contact 25i and closes contact 26i1. - 12o V is thus applied to wire lbl. The glow lamps Gla at the central office and branch offices gl the waste to 'z. B. G115 and Glls, ignite in the branches ASt "and ASt" shown. It speaks to the Bal relay in the exchange and the B relays at all branch points. At the calling branch point AStl5, since the contact 35 s15 is open, the relay S15 'is also excited via its winding II and moves the contacts shown in the drawing in the rest position to the working position. The electrical circuit through the relay S15 and the intercom is opened at contact 56b15. The relay S15 drops out. At all branch points, the B relays have those to be controlled by the elective current. Capacitor resistor arrangements applied to the wire lal, so at the branch point AStlG: earth, capacitor g015, contacts 158 b15, 157 sls, connections i, 3, resistors a56, 156, connection 8, wire lal. At the calling branch point, the same branch from the wire lal via the capacitor resistor arrangement is not made because the contact 162 s15 is open.

In the exchange, relay TY2 is energized: -r-, contact 149 ba "winding I of relay YT7, switching arm i50, selector contact 16, resistance 151, = and is placed in a holding circuit via its winding II :. -f-, contacts 183y1, I84W2, winding 1I of relay W2; Resistance 186, -. The short circuit of the windings I and II of relay X1 are canceled at contacts 95 w2 and 96w2. Opened Furthermore, the contact 61 bal, and the contact 152 bal is closed.

The relay A1 drops out when the contact 25i1 opens and opens the short circuit of the relay T14, so that it responds temporarily. The relay T13 drops out. During the time in which the relay V4 keeps its armature attracted, the winding I of the relay Ab is. switched on: +, contacts 134y1, 1 53 v4, 146 kril, winding I of the relay Abi, -. The relay Abi is placed in a holding circuit that is independent of the contact 153v by closing the contact 135. At contact 142, the one via winding 1a. of . Relay I (ril the existing circuit described earlier is interrupted. Relay Krll drops out and switches relay J1 off.

As long as relay J1 keeps its armature attracted after energizing relay Bai, + 72 V is connected to wire lai via resistor 138, contacts 139 arti, 154 hri3, 1554, 152 bal. With the exception of the calling branch point AStl5, at which, as already mentioned, the contact 162s "'is open, the capacitors are charged at all branch points, for example at the branch point ASt" shown via; connection 8, resistors 156, 256, connections 3 , i, contacts 157s "', 15'8 b", capacitor Kola, earth.

To select the branch point AStl, and also the branch point ASt " a long --- current surge is required. Since the junction AStl5 is in the Is in the call state, there is no influence on the capacitor resistor arrangement. If this junction were also in the rest position, it would, as in section 3 will be explained in detail, including the capacitor resistor arrangement can be influenced in such a way that the connection of the branch point ASt "together with the connection of the branch point AStl6 is being prepared. The final connection then depends on which wire lal or lbl to keep the connection relay energized required power source is switched on in the exchange, because the Winding II of relay R15 is connected to the wire lal and winding II of relay R " applied to the wire lbl.

Since a long surge of + currents is to be sent out, relay J1 may after opening the contact i47 krll does not fall off, it would only be a short one Branch points ASt'1i and ASt "would be given a + current impulse only the capacitors of the branch points ASt "to AStjf are fully charged, but not the condensers of the branch points AStl5 to AStle. At the junction AStl, the charging circuit at contact 162s15 'is known to be open.

The delay in the release of relay J1 is used after the last one from the calling Participants emitted current impulse series on the following Paths excited relay El: +., Contacts 116y1, 117abl, ii8al, 114v4, switching arm I15, Contact 16 of the identification selector KW, contacts 132 hr 13, 207i "relay El, -. As long as the relay J1 is energized, the relay El remains energized via the contacts 3o7 e ": 207i,. The relay El opens, among other things, the charging circuit of the contact 2i8 e1 CONDENSER 22o and connects this via contact 219 e1 parallel to relay l1. After opening the contact I47 kr ", the capacitor 22o discharges through the relay J1, which keeps its armature attracted while the discharge current is flowing. It drops only after the capacitor 22o has been discharged. The extended connection of + to the wire lal brings about a completion of the capacitors of all branch points, at which the capacitor gate resistor arrangements are connected.

After the relay J has dropped, a pre-discharge current surge is closed over the Ader lal to discharge the capacitors at the branch points to be selected by a short-duration optional current. The contacts 55 il, 26i1, 2o7 il are open and the contacts 159i1, 25i are closed. During the release time of the relay El, which is switched off at contact 207i1, - I20 V is applied to wire lbl via contacts 22I e1 and 25i.1. The B relays all remain energized. Via the contacts 16o e1, 159 il and 152 bar , earth is connected to the lap wire. After the relay El has dropped out, the capacitors of the branch points AStl to AStl are fully discharged, while the capacitors of the branch points ASt "to AStls still have such a charge, that connection relays can respond in local discharge circuits, so "relay R" at branch point ASt.

The disconnection of - I20 V from wire lb by opening the contact 22i cl has the drop of the B relays in the branch points and the relay Bal for Episode. The wire lal at the contact 61 bar and the wire lbl at the contacts 25 il, 58 e1 switched through.

At the calling branch point AStl5, the relay B15 drops with a delay since its winding II is short-circuited through contact 161 s1. The relay S1 "has a larger armature drop-out delay than relay b'15, so that Relay S15 after closing contact 56b15 via the contacts that are still closed 64s15 'and 65 s "in the feed circuit that is closed again in the exchange can respond via the relay Al.

The capacitors discharge at the branch points AStl to AStl " via the Wick lungs I of the R relay of these junction points, z. B. at the junction AStl "the capacitor Kol, via contact 173 b1, and winding I of the relay RIG. The Holding windings II of the R relays are connected to the company management. At the branch point AStls the winding II of the relay Rlc is connected to the wire lbi in the following way: earth, contact 172lais "II, 274r16-, connections 4, 5, winding II of the relay Rlo, connections 7, 6, 9, wire lbl. At the branch point AStls is As can be seen from FIG. 6, the holding winding II is also connected to the wire lbl, while the holding winding of the relay at the branch point AStl, with the wire lal communicates. At the last-named junction, the R relay drops out immediately off again, since after switching through the company management in the exchange Earth is connected to the wire lal via the choke coil Drs, so the relay is its Cannot keep anchor tightened. The R relay also drops at the branch point AStls from, although the holding winding is connected to the wire lbl, since the holding winding at this junction opposite to the holding winding at the junction ASt1E is switched on because connections 6, 7 and 4, 5 are not connected to one another connected, but, as FIG. 6 shows, the connections 4, 7 and 5, 6. The R relay the branch point AStls is repolarized and drops.

Only at the branch point AStl, the relay R "remains energized, since the Holding current through the winding II in the same sinter as the excitation current through the Winding I works. There is no @ reversal of polarity.

By connecting the holding winding It of the relay R ", an asymmetry of the company line is created. This has the consequence that in the exchange, after the wires of the company line have been switched through, the differential relay X1 in the holding circuit of the relay Rla, located in the subscriber's feed bridge, responds. It opens the contacts 175 xi and 236 x1. A short circuit of the winding II of the relay b.Y3 is prevented while the call relay Rrl is excited The contact 176v3 lying in series with the contacts 175x and i85 rrl remains open. A short circuit of the winding 1,1 of the relay Ul @ when the contact I 8 j YYl closes is also prevented at this point.

This is followed by a call to the selected branch point ASt ". The relay Rrl is energized at certain time intervals, for example every 5 seconds: -, relay Rrl, contact 167w2, call switch 5", + and closes the contacts currently of interest -168 yrl and 17oyrl . Ringing current is applied via the first-mentioned contact, namely to the wire, in the present case lal, via which the holding current for the relay R10 of the selected branch point ASt16 does not run. The contact 17orrl is in series with the contact 169 u3 and the winding I of the relay X, short-circuits. The ringing current takes the following route: AC power source, contact 168 rrl, capacitor, contacts 17171 "165w2, 77 y1, ° 49w1, 61 bal, wire lal, branch point ASt16, connections 8, 1o, contact 174r16, alarm clock, earth.

If the called subscriber of the branch point AStl lifts his handset, the short circuit of the winding I of the relay S16 'at the contact 172hu16II is canceled. It responds and closes, among other things, its contacts 176s, 6 ', 177 s16', 178 s16 '. The winding II of the relay R1 is short-circuited at contact 176 s16 'and the connection of the speech devices in a bridge to the cores of the company line is prepared at contacts 177 s16' and 178s "'.

The relay R "drops out and closes the contact 179 y16. Via this Contact and the contacts 177 s16 'and 178s16' of the after opening the contact 274y16- due to its anchor dropout delay, holding its anchor tightened for a short time Relay S16 'are the speech sets in series with the relay S1, on the following Paths in bridge to the company management: Ader lal, connection 8, contacts 18o r16, huJ, 178 s16 ', - intercoms, impulse contact nsi ", relay S16, Kontalcte 177s16', 1 & I b16, 179y16 connection 9, wire lbl. The relay Slo responds and holds the circuit just described. Closing of contacts 182 sle and 183s ", which are parallel to contacts 178 s16 'and 177 s16', even after the Relay SIO 'upright.

When contact 274y16 is opened, the asymmetry of the company management at the selected branch point is canceled. As a result, the differential relay X1 drops out in the exchange. Relay V3 responds via contact 236 x1, which among other things closes contact 176v3. The next time relay Rrl is energized, the holding winding II of relay W2 is short-circuited via contacts 175x " 185 ryl, 176v. Relay W2 drops out and opens the circuit of relay Rrl. At the same time, contacts 9.5 w2 and 96w2 are short-circuited of the windings I and II of the differential relay X1, so that during speech communication in the microphone supply circuit only the relay A1 and the choke coil Dr. The relay Y1 continues to be held at contact 234v3 after contact 213 w2 has opened.

The drop in relay X, when the subscriber of the called branching point AStl reports, is the reporting criterion and results in the activation of the counter Z15 of the calling branch point in the following local circuit: +, contacts 187 v3, 188 x1, 189w2, 1o9 cl, counter Z15, contacts 82 ha, 907i, 452, -. When relay W2 drops out, contact 189w2 is opened and the circuit via counter Z "is interrupted again.

If after the end of the conversation "the subscribers of the branch points ASt15 and ASt16 hang up their handsets, the relays Al and h, fall off. The relay V, is the trip relay and brings the devices in the exchange back to the idle position, including closing the contact 1o2 v3 the circuit via the rotary magnet Dkw, which comes about after the relay Y1 drops out: -, magnet Dkw, contacts 102v3, 138.y1, 205n, winding II of relay down " contact 139 kkw, breaker Unt, +. When the identification selector is in the rest position, contact 139 kkw is open. The voter is shut down. The relay Ab, which is still energized during the tripping movement of the selector KW, prevents, as the contact 194ab1 in the incoming occupancy wire is open, an occupation of the company line as long as not all facilities are in the idle position.

The relays S15 and SIG fall in the branch points AStl5 and AStlc away.

For the final connection of one of the determined by an election stream Direction and duration selected branch points is in contrast to the exemplary embodiment I (Fig. I to 3) in the present embodiment II (Fig. 4 to 6) of Unearthed - pole of the normal operating battery, which is grounded with its + pole, depending on of the election process in the exchange either to the Ader Lal or the Core lbl laid. The direction of the current is thus changed.

Has the subscriber of the branch point AStl called and a connection established with the subscriber of the branch point AStls, then in the exchange through the relay U3 the - pole of the service battery from the wire lbl to the wire lal switched to the relay R ", whose winding 1I is on the wire lal, energized to keep. This current reversal has no disconnection of the calling branch point AST " As a result, this aroused this after the call was initiated and during the conversation relay S18 during the selection of the branch point AStl; falls off. His re-excitement through a current flowing over the line in the opposite direction is through the Auxiliary relay Sle ', which is the excitation circuit for the relay S18 at the contacts 177siE, 178s18 'holds closed, secured. A special one, opposite to how the normal operating battery grounded power source is not necessary.

3. The branch point ASt15 is selected via the line selector LW After setting the line selector LW to connection 1 5 of the branch point ASt15, the test relay Plw and the occupancy relay C1 respond if the company line is free. The latter turns on via its contact 197c, in a holding circuit, applies the winding III of the relay N, which also serves as a test relay in incoming traffic, to the switch arm i99 of the identification selector KW at contact 198cl and energizes the contact 2o2 via the contact Zoo cl and the switching arm 2o3 of the preselector VW the isolating relay Trl. The wire 107 is opened at the contact 2o6 cl, thereby preventing the preselector VW from starting when the contact i o5 a1 closes later.

At contact 204c1 a circuit for the rotary magnet Dletv des Identification selector KW closed. The latter is automatically advanced as long as until the relay N. in switch position 15 responds and the circuit at contact 2-o5 n of the rotary solenoid Dkw opens. It is also excited, inter alia. the relay A,: earth, contacts 207y1, 2o811, relay Al, -. Relay V3 is switched on at contact 99a1.

The setting of the identification selector KW determines that a long --- current impulse (the identification of the branching point ASt ") is sent. The excitation of the relays An" KY ", h and Ba- is necessary for this. The relay N has that Relay Kr "switched on: -, contacts 2o9zt, 2i0 kb, 2i i ka, relay Krls winding h, -. It closes its contacts 154 kr13 in the selection circuit and 14o kr "in the circuit of the winding lt of the relay Kr". This responds in series with the relay Ani (winding II): +, contacts 2o9 1v, 2 i okb, 2 ii ka, 13o krl3, winding h of the relay Kr ", contacts 14o krl3, 141v4, i42 abl, switching arm 143, Contact 15 of the identification selector 1 (W, relay Ani, winding II, -. The relay Aytl disconnects at contact 137astl - 72 V and switches on contact 139 old, -E- 72 V. Via contacts 148 krl3 and I47 krl1 is the relay 11 is energized and has applied to the wire lbl at the contact 26i1 - i20 V. As described, the relay Ba and the B relays of all branch points respond. The capacitors at all branch points are connected to the wire lal for charging. The relay Ba, opens the contact 61 bal in the wire lal and applies to the outgoing wire via the contact 152 ba., -1- 72 V. The capacitors at the branch points are charged.

In the exchange, there is the switching arm 15o on the contact 15 stands, the relay W2 in series with the relay U "energizes: -1 -, contact 149 bal, '' Winding I of relay W2; Switching arm 15o, contacts 15, 212 zt3, relay U3, -.

A holding circuit is closed via winding II of relay TV: +, Contacts 183y1, i84w2, winding II of relay W2, resistor 186, -. The relay W. closes at contact 215w, a holding circuit running via contact? -16u3 for the relay U3.

The relay W, energizes the relay Y1 via its contact 213w2, which responds. The feed bridge is prepared at contacts 77y1 and 78y1. The relay El is excited: +, contacts i 16 y1, ii 7 abl, 118a "ii4V4, switching arm ii5, contacts i5, 132kr13, 2o7 il, relay El, -. The relay El opens the contact 2i 8 e1 and connects via 219C1 The charged capacitor 22o parallel to the relay II. Furthermore, the contact 58 e1 is opened and the connection of -i20 V to the wire lbl is prepared via the contact 221 e1 after the relay h has dropped. The relay A1 is switched off at the contact 207y1, which drops out and opens the circuit via relay V3 at contact 99 a1. Relay h4 responds temporarily and energizes relay Ab, -E-, contacts 134y1, i53 v "j46 krll, winding I of relay Abl, -.

The relay Abl is deposited via the contacts 135 and 134y1 in a holding circuit. It opens at contact i 42 from, the circuit via the windings I of the relay An, and lt of the relay Krll. At first only the relay Krl1 drops out, since the relay An is kept energized via its winding I: +, contacts 222 bal, 223w2, 224 to "winding I of the relay Anal, -.

The drop in relay Kr "causes relay J1 to switch off. The relay. J1 is still temporarily due to the discharge current of the capacitor Held at 22o. A + elective current of long duration is thus given over the lal vein, As a result, the capacitors are fully charged at all branch points will. After the capacitor has discharged 22o the relay 11 drops closes contacts I5911, 2511 and opens contacts i 55 il, 26i, and 2o7 il. The relay El is switched off at the last-mentioned contact, which delayed Has anchor drop. After closing the contact 25 il remains - 12o V over the Contact 221 e1 is still connected to wire lbl during the release time of relay El. In the time between the drop in relay h and drop in relay El, earth is over the contacts 16o e "159i, and r52 bal are applied to the wire lal Pre-discharge circuit for the capacitors of all branch points closed, but only the capacitors of the branch points AStll to AS44 are fully discharged. The capacitors of the branch points ASt1s to AStlg are, as they are the pre-discharge circuit runs across two resistors in series, only partially discharged, so that after the relay E'1 in the exchange has dropped out and the pre-discharge circuit has opened at contact i 6o e1 in local discharge circuits of these capacitors relays can address.

The drop in the relay El in the exchange also has the shutdown of - 12o V from the lbl lead. The relay Bal and the B relays all Junction points fall off. The local discharge circuits are located at the branch points the capacitors closed. The R relays of the branch points AStl5 to ASt1e speak and connect their windings II to the company management. At the branch points ASt1s and ASt "these windings are located on the wire lal and at the branch points ASt "and ASt" on the lbl.

The two junction points are created by a long --- circuit AStI5 and AStlE selected. Since relay R15 is only energized at branch point ASt1s is allowed to remain, is the changeover of the --Pole, which is normally connected to wire lbl the service battery on the wire lal required. This switch is yours Relay U3 by closing contacts 228u3, 229u3 and opening contacts 942t3, 97u3 has been carried out.

After connecting the wires lal and lbl, the following circuit exists: -, relay Al, contact 229u3, winding I of relay X1, contacts 77y1, 49w1, 6'i bal, wire lal, branch point ASt15, connections 8, 6, 7, winding II of relay R15, terminals 5, 4, contacts 62 y15, hu 15 II, earth.

At the same time, current also flows through winding II of the R relay Branch point ASti ;. Since this winding is opposite to that of the relay RIs of branch point ASt15 is switched on (connections 5, 6 and 7, 4 are connected to each other), a polarization reversal takes place, which causes the drop of this R-relay has the consequence.

The R relays of the branch points .AStio and ASt ", their windings II lie on the lbl core, drop off.

The differential relay X1, whose winding I is in the holding circuit of the relay R15, responds together with the relay A1. It opens contact 236 xl and thus prevents the relay V3 from being energized when contact 99a1 is closed. Contact 175 xi is opened. The call relay Ryl is switched on at contact 167w2, which is excited as a function of a timer, for example every 5 seconds, and applies the call alternating current source via its contact 168rr. Since the relay U3 is energized, the contact 171 u3 has opened and the contact 230 u3 closed, the ringing current flows via the wire lbl, which is not used to hold the relay R15 of the desired branch point, and at the branch point AStls via the connections 9 , io, the contact 69r15, the alarm clock to earth.

Winding II of the differential relay is active during the ringing current transmission X1 short-circuited at contacts 23i u3, 233 rrl and a short-circuit of the winding I of relay X1 prevents contact 169u3 from being open.

If the called station ASt15 answers, the short circuit of winding I of relay S15 'via the hook switch contact hu15II is canceled when the handset is removed. Relay S15 responds and short-circuits winding II of relay RI5 at contact 63 s15. It also closes contacts 64s15 and 65s15. The relay R "drops out, by opening the contact 62 yls the unbalance of the line produced after the selection of the branch point ASt15 is canceled and the contact 57r15 closes. As a result of its armature drop-out delay, the relay Sls' holds its armature after opening the contact 62 r15 still tightened for a short time, so that the relay S15 is in a bridge to the wires lal, lbl of the company line and responds: wire lal, connection 8, contacts 17 r15, huls I, 65 s15 ', speech apparatus, impulse contact nsils, relay S15, Contacts 64s15 ', 56 b15, 57y15 connection 9y wire lbl. The relay S15 closes the contacts 66 s1 and 67 s15 lying parallel to the contacts 64s15' and 65s15 that the differential relay X1 drops out in the exchange. Current flows through its two oppositely connected windings I and II. Contact 176v is closed. Contact 175 x1 is also closed. The winding II of the relay W2 is short-circuited the next time the contact z85 rrl closes. The relay W drops out, switches off the call relay Rrl and short-circuits the windings I and II of the differential relay X1 at the contacts 95 w2 and 96 w2. The relay U3 continues to be held at contact 2q.5 v3.

A count in the incoming traffic is by opening the contact 1 og cl of the occupancy relay Cl excited during the entire connection prevented.

After the connection has ended and the handset is hung up at the subscriber station ASt15, the relays A1 and h1 drop out and trigger the connection devices. Since the contact 233 abl is closed, after the relay Y1 has dropped out by opening the contact 234v9, the relay Cl is short-circuited via the contacts 235a1, 233 from 195y in series. It drops out and opens the contact 198 c1 Circuit via winding III of relay N and relay Plw of the line selector. The relay N closes the circuit for the rotary magnet Dkw of the identification selector at contact 2o5 n. In this circuit described earlier, winding II of the relay Ab, is located. This relay drops out When the identification selector reaches the rest position, lifts off at contact 233, the short circuit of relay C1 and closes the incoming occupancy wire at contact 194.

IIL In the exemplary embodiments I and II, both the input as also the disconnection of the ringing current by a differential relay, which excited by the unbalance of the line created at the selected branching point and drops again when the asymmetry is removed. To the application of a differential relay however, the invention is not limited. For example, an insensitive Relay used in series with relay A (Fig. 2) or Al (Fig. 5) is placed and only responds if at a branch of your choice the unbalance of the line by connecting the branch connected to earth is established via the holding winding of the relevant connection relay. The relay only needs a single winding to switch the ringing current on and off to be equipped. If the earth is switched off at the junction, this can happen There is no relay in the feed current flowing over both cores of the company line hold and fall off. The relay can then in a manner similar to that shown in Fig.2 and 5 happens to the windings of the differential relay by the control device switched off z. B. be short-circuited.

Claims (9)

PATENT CLAIMS: i. Circuit arrangement for repeated, automatic calls from branch points to company lines in telecommunications systems, in particular telephone systems, characterized in that after the desired branch point (e.g. ASt "ASt") has been selected, an asymmetry (earth connected via R; II to la, R16 II to lbl) is produced, which acts on a relay (X, X1) located in the exchange in the bridge between the wires (la, l6, lal, lbl) of the company line in such a way that this relay (X, X1) repeats the , enables automatic transmission of the ringing current over the company line and that when the called subscriber reports at his branch point, switching means (S. ,, So) cancel the unbalance of the line, whereby the relay located in the bridge (X, X1) is ineffective and the automatic call is ended. 2. Circuit arrangement according to claim i, characterized in that that by the unbalance of the line produced at the called branching point a differential relay located in the exchange in a bridge to the line (X, X1) is excited. 3. Circuit arrangement according to claim i, characterized in that that when the asymmetry is established at the selected branching point, one in the exchange insensitive relay lying in bridge to the line responds, which the Ringing current transmission and that this relay when the unbalance is removed in the direct current circuit running over both cores of the company line (microphone feed) does not remain excited, but drops out and prevents further ringing current transmission. 4. Circuit arrangement according to claim i,. Characterized in that the call current transmission Controlling relays (X, X1) after the selected position has been reported by control devices (W, W2) is switched off in the exchange from the feed bridge. 5. Circuit arrangement according to claim 4, characterized in that the relay (X, X1) is short-circuited (84w, 1 0 1 W, 95 1V2, 96 w2). 6. Circuit arrangement according to claim i, characterized in that at the same time as the call current transmission dominating relay (X, -X.,) the feed bridge relay (A, Al) is energized. 7. Circuit arrangement according to claim 6, characterized in that this Controlling relay (X, X1) the circuit of the feed bridge relay (A, Al) Delay relays energized while a connection is being established and maintained (V1, Tls) holds interrupted (at 175x, a36z1). B. Circuit arrangement according to claim 7, characterized in that the delay relay (V1, Tl3) disconnects of the ringing current (by switching on il, 1 via 141 v1. or preparing the short circuit of W 1I at i 76 v3). 9. Circuit arrangement according to claim 4, characterized in that the relay (X1) controlling the ringtone transmission is switched off by the relay (W2) which switches on the call device to the company line after reporting the selected position. ok Circuit arrangement according to Claim i, characterized in that the circuit in which the relay (X, X1) controlling the call current transmission is influenced by the asymmetry in the branch point runs via a different wire of the company line to the call current. i i. Circuit arrangement according to claim 3 and io, characterized in that that winding of the differential relay (X, X1) which is connected to the wire of the company line carrying the ringing current is short-circuited during the ringing current transmission (e.g. I via 152 u1, 153 ry, 169 tts, 17o yY1 etc.).