DE476279C - Circuit arrangement for telephone systems with dialer operation and several exchanges - Google Patents

Description

The invention relates to telephone systems with dialer operation, in particular to those systems in which the supply current for the subscriber stations is in the group selector instead of being switched on in the line selector. Difficulties arise in such systems in connection and monitoring on when connections are made Switching centers of another system, in which z. B. in the usual way the feed the subscriber stations (both the calling and the called) from the line selector from takes place, to be produced. The present invention now has the purpose of making one safe for such cases as well To create effective arrangement, which is achieved in that the connecting devices or lines in the exchange of the calling subscriber are assigned switching devices, which by connecting devices in the desired Exchange are so differently influenced that they switchovers make through which connections between subscribers of different exchanges in which the feeder bridge arranged in different connection levels (e.g. on the group or line selector) is to be made possible.

In Figs. 1 to 11 is an exemplary embodiment According to the invention, a circuit for establishing a connection in several exchanges shown.

Figs. 1 to 7 show the facilities of a telephone network, which two or several exchanges, which feed the calling as well as the called Place takes place from the group selector, and one or more exchanges of the usual type with feed in the line selector contains. Fig. 8, in conjunction with Figs. 2 to 5, shows a special connection device of a telephone network represents in which all offices with feeding of both participant positions from the group voter are set up. In the. Fig. 9 and 10 are the facilities shown, which is required to establish connections in your own or another exchange if the setting of the voters is done by a surge memory. Fig. 11 shows how Figs. 1 to 7 are to be joined together in order to obtain an overall circuit diagram of the arrangement.

Fig. 1 shows a company management with the subscriber stations A and A ¹ , which is connected to the preselector LS in the exchange. The selection has LS

jointly with other preselectors of the same group access to a number of first group selectors, one of which is shown in Fig. ι. The first group selector is used to establish connections via a second group selector, the circuit of which is shown in Fig. 2, via a third group selector (Fig. 3) to the line selector (Fig. 4) and to a subscriber station B connected to it. This first group selector can also be used to establish connections via a two-wire connection line to a second group selector (Fig. 6) and via the third group selector 5 ″ (Fig. 7) and line selector C to subscriber station 5 ¹ 1 and the second group dialer of Fig. 5 indicated by a rectangle, a callback facility can be reached when a connection with another subscriber on the same company line is desired Subscribers of your own exchange can be used via two further group dialing levels and a line selector.In this case, the supply current for the calling and the called line is switched on in the first group selector.

The second group selector shown in Fig. 2 is reached via the two-wire connection line TL when it is via a first group selector, e.g. B. the one shown in Fig. Ι is occupied. At the left end of the connecting line TL three lines are indicated which lead to a second group selector of the exchange to which the first group selector (Fig. 1) belongs and for establishing connections via a first group selector indicated at the right end of the connecting line TL in the other direction can be used via the connecting line TL from the exchange, the second group selector is shown in Fig. 2. The mode of operation of the switching devices shown in FIGS. R to 7 will now be described in detail. For this purpose it is first assumed that the subscriber station ^ i (Fig. 1) wishes to establish a connection with the subscriber station B (Fig. 4) '.

If the receiver is picked up at subscriber station A , the relay 6 (Fig. 1) of the preselector LS responds via subscriber lines 2 and 3 and applies earth to test wire 4 via its contact 11, whereby the calling subscriber line is connected to the test contacts the line selectors who have access to this subscriber group appear busy. At the same time, the relay 5 is energized in series with the rotary magnet 7 of the preselector via the contact 11. At the contact 12 of the relay 6, the test arm 14 of the preselector LS is connected to the connection between the windings of the relay 5 and the rotary magnet 7. If the connection line on which the test arm of the preselector is free, the through-switch relay 5 responds immediately and occupies the connection line. If, on the other hand, this connection line is already occupied, the winding of the relay 5 is short-circuited by earth at the test contact via the switching arm 14 and cannot respond. The rotary magnet 7 is now excited by its own break contact and the test arm 14 of LS , which advances the switching arms 13 to 15 step by step until a free connection line is found. If, for example, the connecting line with the wires 17 to 19 is free, the relay 5 is not short-circuited and is excited in series with the rotary magnet 7. The magnet 7, however, can no longer respond because the winding of the relay 5 has a high resistance. The relay 5 opens the test circuit at its normally closed contact 9, closes the blocking circuit at its normally closed contact 9 and switches off the call relay from the subscriber lines at its normally closed contacts 8 and 10. At the same time, the subscriber lines 2 and 3 are switched through to the working contacts 8 and 10 via the switching arms 13 and 15 to the wires 17 and 19 of the occupied connecting line.

This creates the following circuit for the surge receiving relay 32 of the first group selector. Battery, upper winding of relay 32, normally closed contacts of relay 31, line 17, switching arm 13, contact 8, line 2, subscriber station A, line 3, contact 10, switching arm 15, line 19, normally closed contact 57, lower winding of relay 32, earth . At contact 58, the following circuit for relays 39 and 40 is closed: earth, winding of relay 39, normally closed contacts 57, 79 and 54, working contact 58, winding of relay 40, battery, earth. The relay 40 opens its contact 78 in the circuit of the relay 35 in order to prevent the latter from responding after the through-switch relay 41 has been energized. In addition, the trip relay 33 is energized via the contact 59 of the relay 32. This opens its normally closed contact 62 in the circuit of the release magnet 42 and prepares a circuit for the lifting magnet on the work contact. At contact 61 earth is over the

Normally closed contacts of the relay 36 controlled by the contact spring 68 are applied to the blocking wire 18, whereby the usual holding circuit for the through-switch relay 5 of the preselector LS is closed before the delay relay 6 has dropped out.

In the first group selector, the relay 33 applies earth to the line via its contact 60 51, creating a circuit for the delayed response relay 34 is closed via the drag contact influenced by contact 84. In this circuit, the relay 34 responds while the relay 31 due to the relatively high resistance of the winding of relay 34 is not energized. The relay 34 connects the upper speech capacitor at the contact 63 with the line 25 via the contact 47 folded over in the eleventh rotation step and via the head contact 44. The line 25 is connected to the secondary winding 24 of a transformer, whose primary winding is in a buzzer circuit. This is the calling Subscriber transmitted an official signal.

Now the calling subscriber station ./i sends one of the first digits of the desired Number corresponding rush series, whereby the rush receiving relay 32 drops out according to the rush number. Here each time it closes a circuit at its contact 59 via the contacts 62 and 84 for winding the lifting magnet 48.

Under the influence of the lifting magnet, the switching arms 86 to 88 of the first group selector are gradually raised to the desired row of contacts. In parallel with the lifting magnet 48, the delay relay 37 is energized, which remains attracted during each series of current impulses. The relay 37 closes at its contact 72 a circuit for the relay 38 via the contact 82 and the head contact closed during the first stroke.

4-5 clock 45. Relay 38 is set at contact 74 a holding circuit for itself via the breaker contact 50 of the rotary magnet 49 and via the head contact 45 and prepares a circuit for the rotary magnet 49 at the contact 75. Be it also mentioned that when the head contacts are turned over on contact 44, the upper speech capacitor disconnected from the official sign wire 25 and connected to the lower winding of the surge receiving relay is brought. According to this, the capacitor is in a bridge to the speech wires and causes a faster dropping of the surge receiving relay at the loop interruptions.

After completion of the lifting movement, the relay 37 drops out and completes its Normally closed contacts the circuit of the rotary magnet 49. The rotary magnet 49 responds, brings the switching arms 86 to 88 with the first contacts of the desired contact row in connection and interrupts at the end of the tightening movement of its armature the circuit of the relay 38 at contact 50. The relay 38 then drops out and opens the circuit of the rotary magnet 49 at contact 75, which is also de-excited and its breaker contact 50 from new closes.

If the connection line connected to these contacts is free, that speaks Through switch relay 41 and occupies the connection line. However, suppose that the connection line is busy, so that the relay 41 through earth at the test contact is short-circuited via the switching arm 87 and cannot respond. In contrast the relay 38 is energized again via the test arm 87 and closes the circuit of the rotary magnet at its contact 75 49, which brings the switching arms 86 to 88 with the second contacts in connection.

This interaction between the relay 38 and the rotary magnet 49 becomes so continued for a long time until a free connection line is reached, e.g. B. the connecting line with the wires 92 to 94. As soon as the switching arms 86 to 88 with the connection contacts of this connecting line in contact are brought, the relay 41 is no longer short-circuited, so that it is in Series with relay 38 responds in the following way: Earth on line 51, Winding of relay 41, shaft contact 46, breaker contact 50, head contact 45, Winding of relay 38, battery, earth. The relay 38 cannot use this circuit respond because the winding of the relay 41 has high resistance. The relay 41 opens the test circuit at normally closed contact 80 and connects via normally open contact 80 Earth to the test arm 87, whereby the occupied connection line for other voters, who also have access to it is made occupied. At contact 82 the relay 41 separates the contact 72 of the relay 37 from the circuit 38, prepares at contact 81 a circuit for the relay 35 before, the contact 84 separates Impulse wire from the lifting magnet 48 and switches it to the winding of the relay 34 um, whereby the latter is disconnected from the grounded line 51 at the same time. At The relay 41 switches the incoming speech wires to the contacts 79 and 85 the switch arms 86 and 88 by, whereby

at the same time the He energized circuit for the relays 39 and 40 on the drag contact influenced by the contact 79 is interrupted. The relays 39 and 40 do not drop out, however, but are kept energized via the connecting line TL and via the two windings of the relay 107 of the second group selector (FIG. 2). The relay 107 is in a bridge to the wires of the connecting line TL via the contacts 121 and r.22 of the switch-off relay 101, via the normally closed contacts of the relay 109 controlled by the contact spring 140 and via the head contact 113. In this circuit, the rice relay 107 speaks Via the connecting line TL in series with the relays 39 and 40 and closes a circuit for the surge relay 102 via the resistor 117 at the contact 134. At the contact 124, the relay 102 closes a circuit for the relay 103 and at the contact 123 the following circuit for the Relay 109: earth, upper winding of relay 109, normally closed contact 143, contact 123, upper winding of relay 105, upper winding of relay io6, battery, earth. In this circuit, the relays 109, 105 and 106 respond, and the relay 109 closes a holding circuit for itself at contact 139 via contact 129 of relay 105. At contact 137, the upper speech capacitor is connected to the wires of the connecting line TL in a bridge and thus in the shunt to the windings of the relay 107. The relay 109 also short-circuits the resistor 117 at its contact 138, whereby the current for the impulse relay 102 is increased, connects the upper winding of the relay 107 directly via its contact 140 to the wires of the connecting line TL, whereby the lower winding of the relay is disconnected at the same time, prepares a holding circuit for the relay 108 at contact 141, whereby at the same time one connection of the lower speech capacitor is connected to earth. At contact 142, the other connection of the lower speech capacitor is disconnected from the lower speech wire and switched to contact 134 of relay 107 via the low-resistance resistor 119. This improves the response of the surge relay 102 to the interruptions at contact 134.

The delay relay 103 excited via contact 124 prepares the setting circuit at contact 127, applies earth to line 171 via contact 126 and separates switch relay 101 from the test wire at contact 125 and connects it to earth, whereby the connection line TL is blocked against seizure from this end.

Now the calling subscriber station sends out the second series of current impulses, through which the relay 32 of the first group selector (Fig. 1) according to the Number of emitted current surges drops and with each drop at the contact 58 den Circuit for the relays 39 and 40 in the bridge to the switching arms 86 and 88 interrupts. When relay 32 drops for the first time, relays 39 and 40 are de-energized, and the relay 40 closes a circuit at its contact 78 via the contact 81 for the relay 35. The relay 35 cannot respond, however, since it is earthed Circuit at contact 64 of the relay. 34 is separated, which via the contacts 59, 62, 84 is energized at the first drop of the relay 32. The relay 34 also closes on Contact 64 the relay 39 short to the current strength of the surge circuit over which the surge receiving relay 107 of the second group selector (Fig. 2) is excited. At contact 63 this applies Relay 34 shunts the upper speech capacitor to the incoming speech lines via shaft contact 47 and head contact 44, the electrical properties of the connecting line for to improve the impulse delivery.

After the end of the series of impulses, the relay 40 responds and remains energized, while the delay relay 34 drops out after a short time, whereby the circuits returned to their idle state.

In the second group selector (Fig. 2) the surge receiving relay 107 drops for each Interruption of his current flow at contact ■ 58 of relay 32 (Fig. 1). Every time opening the contact 134 of the relay 107 the circuit for the impulse relay relay 102 interrupted, which at contact 123 the circuit of the Relays 105, 106 and 109 open. The relays 105 and 106 drop out, while relay 109 has a holding circuit for its lower Winding is kept energized. Before the relay 105 drops out, the holding circuit is of relay 109 via contact 128 of relay 104 is closed. The relay 104 was via the normally closed contact 124 and normally open contact 127 when the relay dropped 102 excited. The relay 104 is used as a delay relay trained and remains active during each series of impulses. Above the contact 124 is with each drop of the relay 102 the following circuit for the Lifting magnets 120 of the second group selector closed: earth, contacts 124, 127,

146, magnet 120 winding, battery, Earth. Under the influence of the lifting magnet 120, the switching arms 148 to 150 gradually raised to the desired row of contacts. During the first stroke, the head contact 114 is closed, see above that the following circuit is established for relay 108: earth, contacts 126, 128 and 145, head contact 114, winding of the Relay 108, battery, earth. The relay 108 prepares the circuit for the rotary magnet 118 at contact 135 and closes at contact 136 the following holding circuit for itself: earth, contacts 141, 147, 136, Breaker contact of rotary magnet 118, head contact 114, winding of relay 108, Battery, earth.

After the end of the series of impulses, the relays 105 and 106 are over the contact 123 of the relay 102 again made to respond for a longer period of time. The relay 105 holds the holding circuit of relay 109 at contact 129 is closed. Shortly afterwards it falls Delay relay 104 and opens the series during the transmission of the rush current closed holding circuit for the lower winding of relay 109 at contact 128. At the normally closed contacts of the relay 104 influenced by the contact 128, the via the Contact 135 prepared circuit for rotary magnet 118 is closed. Through this the second group voter is left to vote freely and looks for a free one to the desired row of contacts connected connecting cable, z. B. the connecting line 161 to 163 running to the third group selector shown in Fig. 3, in the same way as the first group selector. Then the switch relay speaks 110 in the following way: earth, contact 126, line 171, winding of the relay 110, break contact of the rotary magnet 118, head contact 114, winding of relay 108, battery, earth. At contact 144 Relay 110 opens the test circuit and applies ground to test arm 149 of the group selector on, separates solenoid 120 at contact 146 and switches on contact 145 the contact 128 of the relay 104 from in order to prevent a further response of the relay 108. The incoming speech wires are connected to contacts 143 and 147 of relay 110 connected to the switching arms 148 and 150 of the second group selector while at the same time the upper winding of the relay 109 from the one over the upper windings of the Relay 105 and 106 running excitation circuit is disconnected. The relays 105 and 106 are via lines 161 and 163 of the third group selector (Fig. 3) kept energized, while relay 201 this Selector via the normally closed contacts controlled by the contact springs 228 and 232 in the bridge to these lines and the line 163 via the switching arm 150 of the second Group selector and via the contact 141 of the relay 109 is connected to earth.

In the third group selector (Fig. 3) the relay 201 is now energized and closes on Contact 221 creates a circuit from the grounded test lead 162 via contact 230 and resistor 202 for relay 203. This provides a holding circuit at contact 223 for himself, prepares a circuit for the relay at contact 224 204 before, whereby a contact in the circuit of the rotary magnet 210 is opened at the same time prepares a circuit for the lifting magnet 209 at the normally open contact 225 and opens its normally closed contact 225 in the circuit of the trip magnet 206.

When the third series of impulses is emitted, the loop interruptions caused in the circuit of the impulse receiving relay 32 of the first group selector are passed on to the second group selector and from there to the rush receiving relay 201 of the third group selector at contact 123 of the relay 102 (Fig. 2). The relay 201 drops out every time its circuit is interrupted and closes a circuit for the solenoid 209 via the normally open contact 225 at contact 222. By actuating the magnet 209, the switching arms 233 to 235 are gradually raised to the desired row of contacts. After closing the head contact 212, the circuit of the relay 204 is closed via the normally open contact 224 and the contact 207 of the tripping magnet 206 ³ 100. The relay 204 prepares a circuit for the rotary magnet 210 at the contact 226 and closes a holding circuit for itself at the contact 227, which runs via the contact 231 and the breaker contact 211 of the rotary magnet.

The head contacts 214 and 208 closed at the first lifting step of the selector, of which contact 214 is over the contacts 222 and 231 prepared a short circuit for the winding of the relay 203. With each response of the relay 201, the winding is then on the normally open contact 222 of relay 203 short-circuited. This relay therefore acts as a delay relay and does not drop out during the series of impulses.

After the end of the lifting movement, the relay 201 responds again for a longer period of time, so that the relay 203, which is now short-circuited over the head contact 214, drops and at the normally closed contact 224 the circuit of the

Rotary solenoids 210 completed. Under the influence of the magnet 210, the switching arms 233 and 235 are set with the first contact of the Contact series connected, while at the same time the circuit for the relay 204 at the breaker contact 211 is opened. The further free choice proceeds in the same way as for the first and second group voter described, and should therefore not be considered in more detail will. As soon as the switching arms 233 to 235 with the connection contacts of a free connection line, z. B. 236 to 238, the test relay 205 speaks in the following way: Earth to the Wire 162, winding of relay 205, contact 211, head contact 212, winding of relay 204, battery, earth. The relay 205 opens when it is triggered at the normally closed contact 229 the test circuit and applies earth to the test arm 234 of the third group selector via the normally open contact 229. At the contact 231 earth is disconnected from the rush contact 222, while the relay at contact 230 203 is switched off and at the contacts 228 and 232 the speech wires 161 and 163 are brought into connection with the switching arms 233 and 235, whereby at the same time the relay 201 is switched off. The relay speaks in the line selector (Fig. 4) 203 over the head contact 310 and over the line 237 to the grounded test contact at. At the normally closed contact 329, the relay 303 separates the rotary magnet 311 and switches the surge circuit on the solenoid 312, while the contact 327 in the circuit of relay 302 is closed. Via the voice lines 236 and 238 and via the Contacts 314 and 338 will be the surge receiving relay 301 in series with the top windings of relays 105 and 106 of the second Group selector (Fig. 2) energized. Relay 301 closes one at contact 321 Circuit for relay 302, which is connected to earth at test wire 237 via the contacts 321 and 327 runs. Relay 302 connects test wire 237 to contact 323 the trip wire 316 of the line selector and opens the normally closed contact 324 in the circuit of the tripping magnet 307, while there is a holding circuit via the normally open contact 324 closes for itself, which via the contacts 332 and 341 to the grounded line runs. Head contact 309 is bridged at contact 314 and at contact 325 the surge circuit prepared.

If the calling subscriber station now sends out the fourth series of current impulses, the relay 301 of the line selector drops in accordance with the number of current impulses sent in the same way as described above for the third group selector. Each time the relay 301 drops out, the excitation circuit for the relay 302 at the contact 321 is opened, which, however, remains excited via the holding circuit described above. At contact 322, earth is applied to lifting magnet 312 via contact 325. Each time the magnet 312 responds, the switching arms 343 to 345 are raised by one step until they are opposite the row of contacts in which the connection lines of the desired subscriber station B are connected. In parallel to the solenoid 312, the delay relay 305 is energized, which keeps its contacts switched during the entire series of current impulses. At contact 335, relay 305 closes a holding circuit for relay 303, the excitation circuit of which is interrupted during the first stroke of the line selector on the head contact 310.

Shortly after the end of the first series of current impulses acting on the line selector the delay relay 305 drops out and interrupts the holding circuit at contact 335 for the relay 303, so that this also drops out after a short time and the surge circuit of the line selector at contact 329 switches to rotary magnet 311.

When the calling station sends out the next and last series of current impulses, the rotary magnet 311 is energized according to the number of power interruptions for the relay 301 and brings the switching arms 343 to 345 to the connection contacts 346 to 348 of the requested subscriber station B in connection. During the last series of impulses, the delay relay 305 is energized again and separates the test arm 344 from the upper winding of the test relay 306 at the normally closed contact 334 during the rotary movement and switches the test arm 344 to the winding of the relay 304. At contact 336, contact 332 is shunted to maintain the hold circuit of relay 302 if relay 304 is energized during rotation when test arm 344 touches a grounded contact in its row of contacts.

The further operation of the switching devices of the line selector depends on this whether the requested line is free or busy. If it is busy, the relay becomes 304 excited via the switch arm 344 as soon as the switch arms of the line selector hit the connection contacts the required participant positioni? strike and prepares a holding circuit for itself on normally open contact 331 yourself before. If the relay 305 drops out a short time after the end of the last series of current impulses, so becomes the holding circuit for the relay

304 on the drag contact of relay 305, which is controlled by contact spring 334, closed before the excitation circuit via test arm 344 is interrupted. At the Contact 332 is the holding circuit for the relay 302 interrupted, so that this drops and the surge receiving relay 301 at contact 314 from the lower speech artery 238 separates. At the same time the busy signal line 175 is via the contact 333 of the relay 304 connected to the lower speech artery 238. As a result, the calling subscriber station receives a busy signal in a known manner transmitted. If the subscriber then hangs up the phone, the connection is established triggered in the manner described below.

It is now assumed that the requested cleaning point B is free when the switching arms 343 to 345 of the line selector strike the connection contacts 346 to 348. In this case, the relay 304 is not energized, so that when the relay 305 drops out, the following circuit is closed: Earth at the test wire 237, contact 331, upper winding of the relay 306, contact 334, switchboard 344, connection contact 347, test relay 349 des the required subscriber station B arranged preselector LS ¹ , breaker contact and winding of the rotary magnet 350, battery, earth. In this circuit, the relays 306 and 349 are energized, while the rotary magnet 350 cannot respond via the high-resistance winding of the relay 349. The relay 349 is designed as a step relay and, when energized via the upper winding of the relay 306, only switches off the call relay and earth from the connection lines of subscriber station B , while the speaking arms of the preselector LS ^{1 are} not connected to the connection lines.

In the line selector, relay 306 closes a holding circuit for its lower winding at contact 339, connects ground to test contact 347 of the requested subscriber station B via contact 340 and test arm 344 and switches the incoming speech wires to the connection lines of the requested subscriber position B. Calling current is now applied from line 318 via the upper winding of the call relay 303 and via contact 326 to the upper speech wire, while the lower speech wire is connected to earth via contact 330. The ringing current causes the alarm clock, which is located in the bridge to the speech wires, to sound on subscriber station B. The relay 306 further disconnects the surge relay 301 from the incoming speech line 236 at the normally closed contact 338 and switches it over at the normally open contact 338 'to the small capacitor 313, whereby a small part of the ringing current reaches the receiver of the calling subscriber station in a known manner as a dial tone. At contact 341, relay 306 interrupts the holding circuit of relay 302 and prepares a holding circuit for the lower winding of call relay 303. When it drops, the relay 302 separates the winding of the relay 301 from the speech wire 238 and switches through the lower speech wire via the normally closed contact controlled by the contact spring 314 of the relay 302. In the second group selector (Fig. 2) the relays 105 and 106 are de-energized as a result, and the relay 105 opens the holding circuit for the lower winding of the relay 109 at contact 129, so that it drops out and the speech capacitors in the upper and lower speech wires turns on. At contact 139 the relay 109 prepares a holding circuit for the trip relay 103 and separates the two windings of the relay 107 from the lower speech wire at contact 140, while at the same time the lower winding of the relay 107 is connected to the lower speech wire via the high-resistance 115 . Now the two windings of the relay 107 are placed in series with the resistor 115 in a bridge to the incoming speech wires of the connecting line TL .

Tm the first group voter (Fig. 1) the relays 39 and 40 off, as they flow through the high resistance 115 through the low current cannot be maintained. The relay 40 now closes at the contact 78 the following circuit for relay 35: earth, contacts 64, 78, 81 and 66, winding of relay 35, battery, earth. The relay 35 closes a holding circuit at contact 66 for himself and at the same time opens his excitation circuit, prepares at contact 67 a circuit for the relay 36 before and closes at the contact 65 the lower winding of relay 31 briefly. These circuits remain in place until the requested subscriber station reports.

If the receiver is lifted at subscriber station B after receiving the call sign, the call relay 303 of the line selector (Fig. 4) responds in a known manner via its upper winding, closes a holding circuit for itself via contact 328 and disconnects the continuing speech 1Ί5 leads on contacts 326 and 330 from its upper winding.

In the second group selector (Fig. 2), the requested participant will now place over the Windings of the relays 105 and 106 of the microphone supply current supplied so that the relay 105 responds, while the relay 106,

whose lower and upper winding are traversed by currents in opposite directions, cannot be excited. The relay 105 short-circuits the high-value resistor 115 at its contact 130. As a result, the current flowing through the circuit for the relays 39 and 40 is increased in such a way that these relays respond and the relay 40 at the contact 78 via the contact 67 of the relay 35 completes the circuit for the counter relay 36. The relay 36 opens the circuit of the delay relay 37 at the normally closed contact 70 and closes a holding circuit for itself at the normally open contact 70. At the contact 68, the counting battery is applied via the resistor 73 and the contact 71 to the line 18 to the preselector LS , while at the same time the earth is separated.

ao The counting wire 18 is connected to the winding of the insensitive counting magnet 16 via the switching arm 14 of the preselector LS and via the normally open contact 9 and the line 4. The high current flowing through the circuit described above activates the counter magnet and switches the counter forward by one step.

Shortly thereafter, the relay 37 in the first group selector drops out and removes the counting battery by opening its contact 71 from the counting circuit just described, while at the same time via the contacts of the relay 37 closed by the contact spring 71 again Earth at contact 6 χ is connected to blocking wire 18. The winding of the counting magnet 16 is dimensioned in such a way that, after it has been addressed once, keeps energized via the counting circuit to earth at contact 61.

The calling subscriber station A can now establish a voice connection with the requested subscriber B. After the end of the session, the participants hang up their phones again.

Assuming that the listener is hung up at subscriber station B first, the relay 105 of the second group selector (Fig. 2) drops out and removes the short circuit of the high-value resistor 115 by opening its contact 130. As a result, the relays 39 and 40 are de-energized in the same way as already described above. The switching devices remain in the state they have now assumed until the calling subscriber station A also hangs up its receiver.

Once this has happened, relay 32 drops

in the first group selector (Fig. 1) and interrupts the circuit at contact 58 of relay 107 in the second group selector (Fig. 2). The relay 107 drops out and opens the circuit of the impulse relay 102 at contact 134. Also breaks the relay 32 at contact 59 the circuit for the relay 33, whereby a short current impulse via the normally open contact 62 of the relay 33 and via the normally open contact 84 for the relay 34 comes about. However, this has for the current state the connection has no effect.

A short time after its circuit at contact 59 is interrupted, the relay 33 drops out and removes ground by opening the contact 61 from the blocking wire 18, whereby the holding circuits of the relays 35 and 36 are interrupted and these relays drop out. Since earth was separated from the blocking wire 18, the test relay 5 of the preselector LS drops out. At contact 60 the relay 33 removes earth from the line 51, so that the relay 41 is de-energized and the speech connection is disconnected by opening its contacts 79 and 85. The relay 33 also opens the circuit of the relay 34 at the contact 62 and switches the release magnet

42 in the following way: earth at contact 56, contacts 59 and 62, head contact 43, Winding of magnet 42, battery, earth. The release magnet 42 brings the first Group voters return to the rest position in a known manner, in which the head contact

43 opened and thus the circuit for the release magnet 42 is interrupted.

In the second group selector (Fig. 2) the relay 102 is de-energized as a result of the interruption of its circuit at contact 134 of relay 107, as already described above, and opens the circuit of trip relay 103 at contact 124. After a short time, relay 103 drops out and removes ground from trip wire 171 at contact 126, de-energizing relay 110. This separates the switching arms 148 and 150 of the second group selector from the speech wires of the connecting line TL at its contacts 143 and 147. At the contact 127, the relay 103 closes the circuit for the release magnet in, which runs through the contact 124 and the head contact 112, so that the second group selector is returned to the rest position in a known manner.

By breaking contact 126, earth is also separated from the blocking wire 162 leading to the third group selector (Fig. 3), so that relay 205 of the third group selector;, relays 303 and 306 of the line selector (Fig. 4) and relay 349 of the LS ¹ selection drop off. The relay 205 of the third group selector switches on the tripping magnet 206 via the contact 231, which also switches the group selector into the

Brings back rest. The release magnet 206 opens its normally closed contact 207 to a To prevent the rotary magnet 210 from responding if the relay 204 is swept away of the test arm 234 should impinge on an occupied test contact.

In the line selector (Fig. 4) the tripping magnet is activated when relay 306 drops out 307 excited in the following way: Earth on the

to line 316, contacts 341, 332, 324, head contact 308, winding of the tripping magnet 307, battery, earth. The line selector is returned to the rest position in a known manner, whereupon all connection devices used for the connection just described have regained their dormant state.

It is now assumed that the subscriber station A (Fig. 1) connects to

so the subscriber station A ¹ , which is connected to the same company line, wishes to establish. For this purpose, the subscriber A must dial a certain number, whereby the connection to a so-called callback dialer and to a callback facility is established. After lifting the handset on subscriber station A , the preselector LS selects a free first group selector in a known manner,

z. B. the one shown in Fig. 1, from. This is set by the first series of current impulses sent out by subscriber station A and then searches freely for a free continuing connection line in the desired group, e.g. B. the lines 89 to 91, which lead to a second group selector. This second group selector is in Fig. 5 only. indicated by a rectangle, since its circuit corresponds to that of the group selector shown in Fig. 3.

The second series of impulses emitted by the calling subscriber station becomes this group selector is lifted to the desired row of contacts, whereupon the switch arms 401 to 403 with a free continuing connection line, e.g. B. line 404 to 406. Relay 412 (Fig. S) des responds to this Callback dialer on lines 404 and 406 and on contacts 431 and 435 and closes a circuit for the trip relay 415 at its contact 436. This applies earth to line 407 via its contact 443, opens its contact 442 im Circuit of the tripping magnet 423 and prepares a circuit at the normally open contact 442 for the rotary magnet 424.

Is now owned by the calling party spot A, the next and final surge number sent, the circuit of the relay 412 is interrupted according to the number of emitted power surges on the first "group selector. With each drop the relay 412 connects to its normally closed contact 436 a circuit through the contact 442 and the normally closed contact controlled by the contact spring 445 of the relay 416 to the winding of the relay 417 and from there via the winding of the rotary magnet 424 to the battery and earth and 470. The relay 417 is energized in series with the rotary magnet 424 and remains attracted during the entire series of impulses. At contact 447, relay 417 closes a holding circuit for itself and breaks its contact 446 in the circuit, relay 411 The first step of the callback dialer is the side switch 4 25 is closed, via which the relay 416 is energized and a circuit for the tripping magnet 423 at contact 444 and, at the same time, a circuit for the relay 411 at contact 445 is prepared. After the end of the rotary movement, the relay 417 drops out and closes its contact 446 in the circuit of the relay 411.

After sending out all series of current impulses, the calling subscriber puts down his Listener on, whereupon the relay 32 drops out and at the contact 58 the continuing current surge circuit and the circuit for the trip relay 33 opens at contact 59.

In the recall dialer (Fig. 5), relay 412 drops when the surge circuit is interrupted in the first group selector and completes a circuit on contact 436 via the Contacts 442, 445, 446 and 448 for the relay 411. The relay 411 responds and disconnects the voice wires 404 and 406 from the windings of the relay 412 to the normally closed contacts 431 and 435 and switches them to working contacts 431 and 435 via the winding of relay 419 and resistor 426 to contacts 451 and 453 through. Further Relay 411 closes a circuit for relay 415 at contact 432 before the The last one has dropped out, applies the low-resistance winding of the relay via contact 434 414 via the normally closed contacts of the relay 413 controlled by the contact spring 440 to the Blocking vein 405. This is via the switching arm 402 and the line 90 of the second Group selector and via the test arm 87 of the first group selector (Fig. 1), contacts 80, 60 and connected to ground via the lower winding of relay 31. This iao Circuit contains only the low resistance winding of relay 414, so the current

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is strong enough to make the relay 31 to respond. This closes over its contact 55 has a holding circuit for itself to the grounded blocking wire 18 and connects this at the same time with the line 51, whereupon a running over all voters Rare vein is established. At contact 56, relay 31 separates earth from the contact 59 of relay 32 to prevent premature triggering of the group selector and separates the switching arms 86 and 88 from the feed relays 39 at the contacts 54 and 57 and 40 and connects them to the incoming voice wires 17 and 19, whereby the latter simultaneously from the windings of the relay 32 and from the speech capacitors be separated. The connection is now without the interposition of capacitors or feed batteries via the first group selector to the callback facility (Fig. s).

In the callback dialer (Fig. 5), relay 414 speaks in series with the lower winding of relay 31 in the first group selector (Fig. 1) and connects to contact 441 the blocking wire 405 to ground via the top winding of relay 413.

A short time after its circuit at contact 59 is interrupted, relay 33 (Fig. 1) drops out and removes earth from blocking wire 18 at contact 61 and from blocking wire 51 at contact 60. The connection is now made from earth via the upper winding of the relay 413 (Fig. 5) and maintained via the blocking wire 405 of the callback dialer. Now the relay 413 is energized in series with the relay 5 of the preselector LS via the blocking wires i8, 51, 90 and 405. At contact 439, relay 413 closes a holding circuit for itself to grounded line 407, at contact 438 removes the connection between the upper and lower windings of relay 412 and connects the upper winding at contact 438 to the battery and the lower winding at contact 437 with earth. Via the contact 440, earth is applied directly to the ratchet wires 405, the circuit of the relay 414 is interrupted and a Su circuit for the relay 420 is closed via the contact 433, which via the of. the contact spring 452 controlled normally closed contacts of the relay 420 runs. The relay 420 responds, closes a holding circuit for itself at the contact 452, whereby its excitation circuit is interrupted at the same time, and switches the upper and lower speech wire through the contacts 451 and 453 to the switching arms and 422. The switching arms 421 and 422 are in connection with the common ringing wires and 470, via which I ringing current is applied in certain interspaces. This ringing current flows back to the calling subscriber line via the connected voice wires and connecting lines and activates the alarm clock at subscriber stations A and A ¹ .

If the subscriber A ^% then picks up his receiver, the call relay 419 in the call circuit speaks in a known manner and closes a circuit for the relay 418 at its contact 450, which responds and ein.Haltestromkreis for itself via its contact 449 and via the side switch 425 of the callback dialer closes. The relay 411 is switched off at contact 448. This interrupts the circuit of the relay 415 at contact 432 and applies the windings of the relay 412 again to the speech wires 404 and 40ό via its normally closed contacts 431 and 435, whereby the ringing current is separated from the calling subscriber line at the normally open contacts 431 and 435 at the same time. The subscriber stations A and A ^{1 are} supplied with feed current via the windings of the relay 412, so that this relay responds and closes a new circuit for the relay 415 at its contact 436 before it could drop out.

By the silence of the alarm clock on the subscriber station ^ this subscriber recognizes that the requested subscriber station has reported and picks up his receiver, whereupon the conversation can take place immediately without further switchovers.

After finishing the conversation and after hanging up the receiver on both subscriber stations the circuit of the feed relay 412 in the callback selector (Fig. 5) opened. The relay 412 drops out and breaks the circuit of the trip relay 415 at contact 436. The following circuit for the release magnet 423 is now closed : Earth, contacts 436, 442, 444, winding of magnet 423, battery, earth. Under the Influence of the tripping magnet 423, the switching arms 421 and 422 are in their rest position brought back. In this the side switch 425 is open, so that the relay 416 no and 418 drop out and the circuit of the tripping magnet 423 at contact 444 is interrupted will. When relay 415 drops out, ground from line 407 becomes contact disconnected, whereby the relays 413 and are de-energized. The relay 413 removed Ground from the blocking wire 405 at contact 440, making the second group selector in known Way triggered and the relay 31 of the first group selector (Fig. 1) to drop out is brought, which at the contact 56 the circuit for the trigger magnet 42

closes. The first group voter is then put into the rest position in a known manner returned.

If subscriber station A wishes to establish a connection with another subscriber of its own exchange, the first group selector (Fig. I) is raised to any other row except the three illustrated contact rows and then a free second group selector of the same exchange. occupied, which, for example, can act as a 10000 voter when establishing a connection. This second group selector can be switched in the same way as the group selector shown in Fig. 3 and is set by the second impulse loan sent by the calling subscriber station, whereupon it occupies a similarly switched third group selector, which serves as a 10000 selector. This group selector is set by the third series of impulses and occupies a free downstream line selector similar to the one shown in Fig. 4, which is set to the desired connection line through the last two series of impulses.

In order to explain the establishment of a connection between an exchange, in which both the called party and the calling party are fed from the same group selector, and an ordinary two-wire exchange, it is assumed that subscriber station A is connected to subscriber station B ¹ (Fig. 7) wants to connect, which is connected to a two-wire exchange, in which the feed is carried out on both sides from the line selector. When lifting the handset at subscriber station A , the preselector LS selects a free first group selector, e.g. B. the one shown in Fig. Ι, from. This group selector is lifted to a specific row of contacts by the first impulse series and searches freely for a free connection line leading to a second group selector of an exchange of another system, e.g. B. the line TL ¹ (Fig. 6). At the incoming end of this connecting line, relay 501 of the second group selector (Fig. 6), which is in a bridge to the incoming end of connecting line TL ^1, is energized and closes a circuit at contact 521 via resistor 517 for relay 503. This speaks on and energizes the delay relay 504 via its contact 526, which prepares the circuit for the solenoid 515 at contact 529 and applies earth to the trip wire 516 of the second group selector at contact 528, whereby a circuit via the contact 538 for the winding of the relay 502 is closed will. At contact 523, relay 502 establishes a holding circuit for itself, which runs via contact 534 to grounded line 516 and, via its contact 524, connects the upper winding of relay 501 alone to the incoming voice wires, while at the same time establishing the connection between the upper and lower winding of relay 501 is separated. A circuit for the lower winding of the relay 507 is also closed via the line 516, but this circuit does not respond since this winding consists of relatively few turns with high resistance.

When the calling station sends out the second series of rushes, the relay 501 is brought to drop with each rush, since its circuit is interrupted at contact 58 of the relay 32 (Fig. 1) in the first group selector. Each time the relay 501 drops out, the circuit of the relay 503 is opened at the contact 521. The relay 503 closes a circuit for the lifting magnet 515 at its break contact 526 via the contacts 539 and 540. The switching arms 542 to 544 of the group selector are gradually raised to the desired row of contacts by the magnet 515. In parallel with the lifting magnet 515, the delay relay 505 is excited at the first current impulse and remains actuated during the entire series of current impulses. Resistor 517 is bridged at contact 531 of this relay in order to ensure reliable response of relay 503. The relay 505 also closes its contact 532 in the circuit of the relay 506, which is energized after closing the head contact 513 at the first stroke of the selector in the following way: Earth, contact 528, line 516, contacts 53 ² > 537. Head contact 513, winding of the Relay 506, battery, earth. At contact 533 ', relay 506 closes a holding circuit for itself, which runs via the break contact of rotary magnet 514 and prepares the circuit for rotary magnet 514 at contact 533.

After completion of the lifting movement, the delay relay 505 drops out and completes the circuit for the rotary magnet 514 by closing the through the contact spring 532 controlled contacts of the relay 505. The rotary magnet 514 brings the switching arms 542 to 544 in connection with the first contacts of the ■ selected contact row. now the switching arms are advanced until a free one to a subordinate group selector leading connection line, e.g. B. the cable with wires 545 to 547,

has been found. Then the relay 508 responds, opens the excitation circuit of the relay 502 at contact 538, which remains energized via the contacts 523 and 534, switches off the lifting magnet 515 at contact 540 and the contact 532 of the relay 505 at contact 537, for a second time To prevent relay 506 from responding. The test circuit is opened at the normally closed contact 539 of the relay 508 and earth is applied to the switching arm 543 and the blocking wire 546 via the normally open contact 539, and the incoming speech wires are connected to the speech wires 545 and 547 of the contacts 536 and 54t via the switching arms 542 and 544 connected connecting line. As a result, the relay 601 of the selector S ¹ . (Fig. 7) excited. At the contact 611, the relay 601 closes a circuit for the relay 602, which at its contacts 612 and 613 prepares the selector 5 for receiving the further series of current impulses in a known manner.

The current loop for energizing relay 601 comprises line 545, the Switching arm 542, contacts 536 and 530, the upper winding of the electrically polarized Relay 507, contact 525, the left winding of the choke coil 509, the contacts 527, 541, the switching arm 544 and the line 547. Now both windings of the relay 507 are live, but the relay cannot respond because its windings are carrying currents flow in the opposite direction, so that the magnetic fields cancel each other out.

If the calling subscriber now sends out the third series of current impulses, relay 501 of the second group selector (Fig. 6) at contact 521 transmits the recorded current impulses to relay 503, which, by opening its contact 527, relays 601 to waste according to the number of current impulses received brings. The relay 60 r transmits the current impulses picked up in a known manner to the solenoid of the third group selector Sj so that its switching arms are raised to the desired row of contacts and then a connection line of the desired group leading to a free downstream line selector, ζ. B. select the connecting line 621 to 623 connected to the line selector C. Then the through-switch relay 603 of the third group selector 5 "responds in a known manner and switches the incoming speech wires 545 and 547 through to the speech wires f) 2i and 623 leading to the line selector C. The relay 632 which is in the bridge to the incoming speech wires is now energized, is prepared whereby the line selector C in known W ^T else for the recording of the last two rows of surge.

In the second group selector (Fig. 6), when relay 503 drops for the first time, relay 505 is made to respond via normally open contact 529 and remains energized during the series of impulses. At contact 530 the relay 505 closes a direct connection between the switching arms 542 and 544, as a result of which the current intensity in the circuit of the relay 601 is increased from 5 ¹ during the current impulse.

When the calling station sends out the next two series of current impulses, the line selector C is set ^{to the connection contacts of the desired subscriber line B 1} in a manner similar to that described above for the line selector (Fig. 4). If the desired subscriber is free, ringing current is applied to his connection line and the commutation relay 631 is energized when the receiver is lifted at subscriber station B ^1. The relay 631 reverses the direction of the current flowing over the lines 621 and 623 and over the windings of the relay 632, whereby the relay 507 of the second group selector (Fig. 6) is made to respond, since its two windings now have currents in the same direction are flowed through. At contact 534 it opens the holding circuit of delay relay 502 and, before relay 502 can drop out, switches high-resistance resistor 516 at contact 535 into the bridge over the wires of the incoming connection line TZA This bridge now includes the upper winding of relay 501, the Normally open contact 524 of relay 502, resistor 516 and contact 535.

In the first group selector (Fig. 1), the current weakening in the bridge im second group selector the relays 39 and 40 brought to waste, whereupon the latter a circuit for the relay 35 closes, which the switching operations described above evokes.

Shortly after opening its circuit at contact 534, relay 502 (Fig. 6) drops out and, by turning over its contact 524, re-establishes the connection between the upper and lower winding of the relay, which disconnects resistor 516 from the bridge . This again increases the current through the loop of the connecting line TL ', so that the relays 39 and 40 in the first group selector (Fig. 1) respond again and the relay 40 establishes the counting circuit in the manner described above, so that the counting

magnet 16 of the calling subscriber station is put into action.

The speech connection between subscriber stations A and B ¹ is now established. After the conversation has ended, subscriber station B ¹ may hang up its receiver first. As a result, the relay 631 of the line selector C is de-energized and reverses the current flowing via the voice lines to the second group selector, so that the relay 507 drops out. At contact 535 of this relay, the high-resistance resistor 516 is placed back in the bridge to the incoming end of the connection line TL ¹ , whereby the relays 39 and 40 in the first group selector (Fig. 1) drop out and the relay 40 is a monitoring device whose mode of operation is described below should be switched on. When the receiver is hung up at the calling station / ί, the first group selector and the preselector LS are triggered in the manner described above. When relay 32 in the first group selector drops (Fig. 1), the circuit for relay 501 of the second group selector (Fig. 6) is interrupted at contact 58, so that it drops out and the relay at contact 521

503 turns off. The relay 503 opens the circuit of the delay relay 504 at its contact 526 and the circuit for the relay 632 of the line selector C at contact 527. After a short time the relay drops

504 of the second group selector, removed from the contact 528 earth from the holding conductor 516 and energized via its contact 529 and via the head contact 511, the release magnet 510, which returns the second group selector in a known manner to the rest position. After the relay 632 of the line selector C (Fig. 7) drops out, this is also triggered and separated from the blocking wire 622 by opening a contact of the trip relay earth (not shown). Now the relay 603 of the third group selector 5 also drops out, whereupon this is also returned to the rest position.

Let us now consider the switching processes that take place when a requested subscriber station, e.g. B. B _{1 is} occupied. The second group selector (Fig. 2) is switched in such a way that the speech lines are only switched through after setting the line selector (Fig. 4) and when the requested subscriber station B is free. The connection takes place when the surge receiving relay 301 of the line selector is switched off. If the requested line is busy, the relay 304 opens the circuit of the relay 302 at the contact 332. The relay 302 drops out and disconnects the relay 301 at the contact 314 from the speech wire 238. This results in the switching through in the second group selector (Fig. 2), so that the speech circuit is closed via this selector, as explained above. At the contact 333 of the relay 304, a busy signal is applied to the lower voice wire 238, which reaches the receiver of the calling subscriber station via the voice lines. A DC circuit is also applied to line 175 via this circuit with interruptions. This facility is set up in order to give an officer the usual flicker signal if the connection has been established by the officer. In the present case, the relays 105 and 106 of the second group selector respond via the lower speech line during the busy signaling. As a result, a circuit for the relay 103 is closed at the contact 129 of the relay 105 and via the normally closed contacts of the relay 109 controlled by the contact spring 139, which circuit now remains energized regardless of the state of the relay 102. The relay 106 applies the battery to the lower voice wire via the resistor 116 and the contact 131 in order to switch on the final signaling at the workstation of an officer, if the connection has been established by the officer. In addition, the relay 39 of the first group selector (Fig. 1), which is connected between the lower speech wire and earth, is excited via this circuit. The relay 39 closes at its contact 76 a circuit for the relay 33, which is now kept energized regardless of the state of the relay 32.

Once the battery is disconnected from line 175 by the busy signal machine has been, the switching means influenced by this line are in their idle state set back. It should also be mentioned that the breaker, which battery to the Line 175 applies, works very slowly and the length of time between the successive Turning on the battery is long enough to trigger the connection.

Should the third group selector (Fig. 3) not be free in the desired row of contacts If you find more connecting lines, the shaft contact becomes in the eleventh turning step 213 closed, via which the line 175 with the switching arm 235 in connection is brought. As soon as relay 205 has been switched through, the busy signal is output via line 175 given to the calling subscriber station as described above. Same switching operations take place when the second group

selector (Fig. 2) can no longer find a free output in the desired contact row.

If the first group selector (Fig. 1) is busy, all further Connecting lines of a row of contacts in the eleventh turning step, the contacts 46 and 47 actuated, so that the through-switch relay 41 can not respond because its circuit at contact 46 is interrupted. This causes the counting magnet 16 to be actuated the calling subscriber station prevented, which take place when the relay 41 responds would. A busy signal is sent to the lower speech artery via the shaft contact 47, which is closed in the eleventh turning step 19 over the head contact 44 applied to the calling subscriber station from the busy all via the first group voter "in a specific group »Ο notify connecting lines. Line selector C (Fig. 7) is also included equipped with a busy signal relay 640, which is excited in the usual way and a Busy signal to the lower speech line 623 turns on when the requested subscriber station should be busy. Since the busy signal relay 640 is not like the line selector shown in Fig. 4 with contacts which cause a current reversal via lines 621 and 623, this means that no switching can take place in the second group selector (Fig. 6). The switching of the first and second group selector is made in such a way that the interconnection for speech traffic for the transmission of the busy signal is not necessary is in. Speech capacitors are switched on at every state of the connection. The third group selector finds 6 "(Fig. 7) there will be no free further connecting line in the selected contact row in the eleventh rotation step, contacts 604 and 605 are turned over. By opening the contact 604 a response of the switch relay 603 is prevented, while on the Contact 605 a busy signal is connected to the lower speech wire 547. In a similar way In this way, a busy signal is connected to the lower speech line of the second group selector (Fig. 6), if this does not have a free exit in the requested Group finds.

The mode of operation of some of the monitoring characters assigned to the first group selector (Fig. 1) will now be described in more detail. A lamp 26 is assigned to each first group selector and is lit up as soon as the group selector is occupied. The circuit for the lamp 26 runs in the following way: earth at contact 64, contact 78 of relay 40 ^ which is excited immediately when the group selector is occupied, contact 67, lamp 26, winding of relay 28, battery, earth. In this circuit, the relay 28 also responds and prepares a circuit to an alarm or registration device, which can be closed by pressing the button 30 in order to determine the occupancy of the group selector at certain times of the day.

During each series of impulses, the delay relay 34 is energized and opens the circuit of the lamp 26 at the normally closed contact 64. In contrast, a new circuit for the lamp 26 is closed at the upper normally open contact 64 via the line 97. When switching through in the first group selector, the relay 35 responds, as described above, and opens the circuit for the lamp 26 at the break contact 67 the hanging of the handset at the calling subscriber station on contact 78 of the relay 40 is closed. Then the lamp 27 lights up in the following circuit: earth on normally closed contact 64, contacts 78, 81, 69, lamp 27, winding of a control relay, battery, earth. The lighting of this lamp indicates that the connection is being maintained by the requested subscriber station while the calling station has already hung up. The circuit of the lamp 27 is only interrupted after the requested subscriber station also renounces the connection. In order to describe the mode of operation of the arrangement for telephone networks with exchanges in which both subscribers are fed from the group selector, Fig. 1 must be replaced by Fig. 8. The first group selector shown in Fig. 8 differs from the one shown in Fig. 1 in that the speech wires of the latter are only connected to the switching arms via capacitors when the sound is transmitted through them, while the speech wires in the former already open when the group selector is occupied the switching arms are switched through to enable busy signals or similar monitoring currents independently of the through-connection in a normal two-wire exchange. If all exchanges in a network have been set up with power from the group wobbler, the first group selector shown in Fig. 8 achieves better current impulses because the impulse circuit is not hindered by the connection of speech capacitors during the impulse transmission. Another difference in the circuit of the first

The group selector of Fig. 8 and Fig. Ι consists in the fact that the release wire of the former is connected to earth via the lower low-resistance winding of the relay 721 during the current impulse, while in the group selector according to Fig. 1 the release wire is independent of the low-resistance winding of the through switch relay is connected to earth at all times. This safety measure is required in Fig. Ι because of the relatively low resistance of the rotary magnets of the upstream preselector, while on the other hand the magnets of the preselector, ζ. Β. LS ² (Fig. 8), which have access to the first group selector in Fig. 8, are provided with windings of higher resistance so that • they do not need the strong current of the first-mentioned preselector.

The establishment of a connection via the first group selector shown in FIG. 8 will now be described in more detail, for what purpose it is assumed that subscriber station A ² wishes to establish a connection with subscriber station B (FIG. 4). When lifting the handset of the subscriber station A ² of the selection LS ² starts up and is in a known manner, a free secondary connection pipe, z. B. the one shown with the wires 781 to 783 in Fig. 8.

When seizing the first group dialer assigned to this connection line the relay 722 speaks over the line loop of the calling party. Participant to and closes a circuit at contact 745 via the circuit controlled by contact spring 766 Normally closed contacts of relay 730 for the upper winding of relay 729 in series with the Winding of relay 728. These two relays respond and relay 729 switches Connect the delay relay 724 to the impulse wire at contact 764 and disconnect at contact 765 the lower speaking capacitor and closes the winding of the relay 727 kuiz.

At contact 762 the relay 729 disconnects the winding of the relay 725, connects the holding wire 784 of the group selector with the blocking wire 782 at contact 761, removes the short circuit of the lower winding of the relay 721 at the normally closed contact 760 and switches the monitoring lamp 737 via the normally open contact 760 a. At the break contact 759, the upper speech capacitor is applied from the speech line and via the head contact 733 to the exchange signal line 735. The relay 728 closes its contact 758 in the holding circuit of the relay 729. The relay 722 energizes the delay relay 723 via its contact 746, which prepares the circuit of the rotary magnet 733 at the contact 748, interrupts the circuit of the tripping magnet 732 at the normally closed contact 749 and the normally open contact 749 Circuit of the solenoid 736 prepared and applied to the contact 747 earth via the low-resistance winding of the insensitive relay 721 to the holding wire 784. The test relay of LS ² in series with the rotary magnet is kept energized via this wire, the contact 761, blocking wire 782 and the test arm of the preselector LS ^2. In addition, the following holding circuit is now established for relay 729: earth, battery, lower winding of relay 729, contacts 763, 758 to earthed trip wire 784.

When the caller sends out the first series of impulses, the relay drops 722 according to the number of current impulses sent and completed at contact 746 the circuit for the solenoid 736. Be under the influence of this magnet the switch arms 772 to 774 lifted to the selected row of contacts. Parallel to the lifting magnet 736, the delay relay 724 is excited via the contact 764, which during the entire series of impulses remains in action. The relay closes at contact 750 724 via the contact 768 and the head contact closed during the first lifting step 734 a circuit for the relay 726. This responds and closes at the contact 754 a holding circuit for itself via the following path: earth at contact 743, Contacts 765, 744, 771, 754, breaker contact 755 of the rotary magnet 733, head contact 734, winding of relay 726, battery, earth. The relay prepares at contact 753 726 the circuit of the rotary solenoid 733. The relay 724 closes an auxiliary path for the holding circuit at contact 750 of relay 729 to prevent this relay dropping out when contact 758 opens, because the relay 728 with interruption of its circuit at the contact 745 with each drop of relay 722 is de-excited.

At the end of the stroke movement, relay 728 responds again and closes the original one Holding circuit of relay 729. A short time after the end of the first series of impulses the delay relay 724 drops out and completes the circuit at contact 750 of the rotary magnet 733. The rotary magnet 733 brings the switching arms 772 to 774 with the first contacts of the selected Contact row in connection and opens the contact 755, so that the relay 726 drops out and opens the circuit of the rotary solenoid at contact 753. The further free choice proceeds in the manner described above until a free connection line of the selected contact series, e.g. B. the connecting cable with wires 92 to 94,

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is found. Then the relay 730 responds in the following way: earth on the holding wire 784, winding of relay 730, breaker contact 755, head contact 734, winding of relay 726, battery, earth. At contact 769, relay 730 disconnects solenoid 736 from the impulse wire, opens the test circuit at normally closed contact 767, connects test arm 773 to grounded trip wire 784 via normally open contact 767 and switches the incoming speech lines to the switching arms via contacts 766 and 771 772 and 774 through, which at the same time the upper winding of the relay 729 is disconnected from the circuit of the relay 728. The relay 728 is kept energized via the bridge closed at the incoming end of the busy connecting line TL and via the contacts 771, 744, 765 and 743. In the second group selector (Fig. 2) the bridge relay 107 is energized, which prepares the group selector for its setting in the manner described above.

By the second series of impulses emitted by the calling subscriber station the relay 722 is de-energized with each current surge and opens the circuit of the relay 107 of the second group selector (Fig. 2) on contact 745, so that this is on the desired Contact row is set. With each drop, relay 722 also closes a circuit for the delay relay at contact 746 724, which remains energized during the entire current surge series and the auxiliary path described above for the holding circuit of relay 729 closes.

The transmission of the remaining series of current impulses as well as the setting of the subordinate voters takes place in a similar manner. If the line selector (Fig. 4) is set to the connection contacts of the requested subscriber station, the switching takes place in the second group selector (Fig. 2), whereby the resistance of the bridge over the incoming end of the connection line TL is increased by switching on the resistor 115, so that the relay

728 (Fig. 8) drops and the holding circuit of the through switch relay 729 at contact 758 interrupts. The relay 729 drops out and sets the speech circuit at the contacts 759 and 765 here. At contact 760 of the relay

729 the lower winding of the relay 721 is short-circuited and at the same time on the contact the connection between the release wire 784 and the blocking wire 782 is interrupted. The holding circuit of the relay 729 is interrupted at contact 763, while the circuit for the relay is interrupted at contact 764 prepared and at contact 762 the circuit for the relay 725 via the contacts 753, 750 and 748 is closed. The relay 725 responds and prepares the counting circuit before.

When the requested participant reports, the resistor 115 in the second group selector (Fig. 2) is short-circuited as described above, whereupon the relays 727 and 728 in the first group selector (Fig. 8) respond again. Relay 728 completes a circuit at contact 758 via resistor 735 and contact 764 for relay 724. Relay 724 closes a holding circuit for itself at contact 750, and at the same time the circuit of relay 725 is opened. Via the contact 751 and the briefly closed contact 752 of the delay relay 725, the counting battery is applied to the blocking wire 782 via the resistor 734. The counting magnet of the calling subscriber station now advances the counter by one step in a known manner. Shortly thereafter, relay 725 drops out and removes the counting battery from locking wheels 782.

After the conversation has ended, the connected participants hang theirs Handset one. Assuming that the requested subscriber site hangs first, fall the relays 727 and 728 from, whereby only the monitoring lamp 737 over the contact 756 and switched on via the contacts of the relay 724 controlled by the contact spring 751 will.

If the calling station hangs up, the relay 722 drops out and interrupts the circuit of the delay relay 723 at contact 746. After a short time, this too is de-energized, opens the circuit of the relay 724 at contact 748, separates earth from the holding wire 784 and from the blocking wire 782 at contact 747 and closes a circuit at contact 749 via the head contact 731 for the release magnet 732. The release magnet 732 responds and returns the first group selector to the rest position in a known manner. The through switch relay of the preselector LS ² and the through switch relay 730 of the first group selector drop out as soon as earth is disconnected from the blocking wire 782. The other group and line dialers used for the connection are triggered in the manner described above and should therefore not be considered in more detail.

If the subscriber station A ² wishes to establish a connection with the subscriber station A ", which is on the same company line, a special number iao is dialed, whereby a connection via the first group selector and via the return

call dialer (Fig. 5) is established. In this case, as described above, battery Via the low-resistance winding of the relay 414 to the blocking wire 405 for a short time (Fig. 5) applied, whereby the insensitive relay 721 of the first group selector (Fig. 8) is made to respond. This includes one at its contact 742 Holding circuit for itself and switches the incoming on contacts 741 and 744 Speech wires 781 and 783 directly to the switching arms 772 and 774 through, and at the same time the feed bridges are cut off. Thereupon the relays 722 and 723 drop out, while the connection devices by applying ground to the blocking wire 405 in the Callback dialer (Fig. 5) must be kept set. The first group voter (Fig. 8) cannot be triggered because the circuit for the release magnet 732 is on contact 743 is open. The completion of such a connection and its release after the end of the conversation is similar Way, as already described above, in front of you, so that a further consideration these switching operations are unnecessary.

It should also be mentioned that the first group voter (Fig. 8) with regard to his slightly different mode of operation is only provided with a monitoring lamp. These Lamp 737 is made to light up via contact 760 as soon as the group selector is occupied. The circuit for the lamp remains in place until it is switched through and is then interrupted when relay 729 drops out. When reporting the requested Participant relay 728 was energized, which is a circuit for relay 724 closes. This prepares the contact 751

♦ ο circuit of lamp 737 in front of which over the contact 756 of the relay 727 is closed when the called party first hooks up. If, on the other hand, a connection to the workplace of a civil servant is established via the first group selector, so this can maintain the connection by applying a battery to the lower speech artery, whereby the relay 727 is energized and the circuit for the monitoring lamp 737 at contact 756 closes. This The circuit then runs through contacts 743, 746 and through contact 749 of the relay 723. The trip relay 723 is grounded in this case in a circuit from the Holding lead 784 maintained through contacts 758 and 757. The triggering of the first group voter and the extinction the monitoring lamp 737 takes place as soon as the officer battery from the lower speech artery removed.

To the interaction of the present circuits with a surge storage To explain in more detail, Fig. 9 takes the place of Fig. 1, while Fig. 10 must be placed under Fig. 9. The first group selector in Fig. 9 is similar connected to the one shown in Fig. 1, in which the speech capacitors in the Rest position between the feed bridges. A major difference between the two group selectors is that the surge receiving relay of the in Fig. 9 the group selector shown does not act directly on the solenoid of the selector, but first the lifting magnet of the current surge accumulator (Fig. 10) and the other moving magnets the setting switchgear of the current surge storage is operated, and that then a special transmitter device of the current surge storage is the setting of the lifting magnet th via a surge relay as well as setting the rest to manufacture connection required selector independent of the impulse relay of the first group selector according to its setting.

Another difference between the circuit of the group selector in Fig. 9 and that of Fig. 1 is that the counting magnet of the calling subscriber station is excited via a fourth wire of the preselector and not by switching on a special one Counting battery to the blocking vein.

For a more detailed description of the mode of operation of the first group selector in connection with a surge storage device, it is assumed that subscriber station A * wishes to establish a connection with subscriber station B (Fig. 4). When taking off. of the handset on the subscriber station A ⁴ = the preselector LS * is left on and occupies a free first group selector, e.g. B. the one shown in Fig. 9, via lines 830 to 833. In the first group selector, relay 812 is excited via the line loop of the calling subscriber and closes a circuit for delay relay 813 at contact 846. Relay 813 connects to contact 847 Earth via the low-resistance lower winding of the relay 811 im to the blocking wire 831, whereupon the usual Sp err circuit for the preselector LS ^{3 is} closed. At contact 848, relay 813 prepares a circuit for rotary magnet 827 and opens contact 849 in the circuit of tripping magnet 822.By applying earth to blocking wire 831, relay 818 is energized and closes a circuit at contact 859 via contacts 850 , 853, 855 for the monitoring lamp 892. and connects the line 893 ¹ with the lower one at contact 860

Speech wire 832. Via this line and contact 925 (Fig. 10) of relay 903 is transmits the telephone number to the calling subscriber station.

S When the first series of impulses is sent, relay 812 of the first group selector (Fig. 9) drops out with each impulse and closes the following circuit for the lifting magnet 908 of the memory selector (Fig. 10): Earth, contact 843, 846, 849, Line 893, contact 924 (Fig. 10), winding of delay relay 902, lifting magnet 908, battery, earth, the switching arms 930 to 933 of the Memory selector raised to the desired contact row. In series with the lifting magnet 908, the relay 902 is energized at the first rush and remains in action throughout the series of rushes. At the contact 923 the circuit of the relay 901 is prepared, which in the first stroke step is completed by closing the head contact 905. This circuit runs over line 896, which is grounded via contacts 867 and 848. The relay 901 prepares at contact 922 a circuit for the rotary magnet 904 and closes a holding circuit for itself at contact 921 itself, which via the breaker contact 911 of the rotary magnet 904 to the grounded Line 896 runs. After completion of the lifting movement, the relay 902 drops out and completes the circuit of the rotary magnet 904 via those controlled by the contact spring 923 Contacts of relay 902. This leaves the rotary magnet on for free choice, which goes on in a known manner. If a free surge storage device, ζ. B. the one accessible via lines 934 to 937, occupied so the relay 903 responds in series with the relay 901, opens the Test circuit at normally closed contact 926 and connects to ground via normally open contact 926 Test arm 931 and thus to the test contact of the occupied surge storage device. At the Contact 925 of relay 903 disconnects the official sign, at contact 927 the switching arm 932 of the memory selector is grounded, at contact 929 the transmission circuit is closed and at break contact 924 the Lifting magnet 908 of the memory selector disconnected from the surge line 893, while on Normally open contact 924 the impulse circuit arriving from the first group selector via the Switching arm 930 is switched to the adjusting members of the receiving switchgear. in the Impulse storage is now the relay 941 via the line 936 and the relay 940 via the line 935 is energized, which triggers the setting switchgear of the surge memory impede.

In the first group selector (Fig. 9), relay 819 is energized in the following way: Earth, lower winding- of relay 819, from the contact spring 872 controlled rest conacts of the relay 821, line 897, contact 929, switch arm 933 of the memory selector, line 937, normally closed contact of relay 938, resistor 942, battery, earth. The relay 819 closes a circuit at contact 862 for the relay 816, which is from the earthed contact 848 via the contacts 867 and 866 extends. The relay 816 responds and prepares a circuit at contact 856 for the solenoid 826 and a circuit for the relay 817 at contact 854. When the next series of impulses is sent by the calling station, this will be Relay 812 de-energizes and transfers over according to the number of incoming current surges the break contact '846 and via the line 893 earth to the switching arm 930 of the memory selector. The switch arm 930 is stationary with the rush wire 934 of the rush memory in connection, via which the receiving switchgear of the same is set will. The rest of the impulse series transmitted over the same circuit are used to set additional receiving switchgear of the surge storage system in a known manner.

At a certain time, which depends on the type of surge storage device used, the transmission device of the same is put into action, whereupon the impulse relay 938 causes the emission of the first series of impulses. With every current surge emitted by the transmitter of the surge memory the relay 938 responds and opens its normally closed contact, whereby the relay 819 drops and at contact 862 a circuit via contacts 856 and 868 for the lifting magnet 826 closes. This lifts the switching arms 879 to 881 to the desired row of contacts. When the group selector is lifted for the first time, the head contact 824 is closed, via which the relay 817 responds in the following way: Earth at the contact 848, contacts 854 and 874, head contact 824, winding of relay 817, battery, earth. At the Contact 857 prepares relay 817 for a circuit for rotary magnet 827 and closes a holding circuit for itself at contact 858 via the breaker contact 828 of the rotary magnet 827 and via the contact 871, at the head contact the relay 816 is connected to the normally closed contact 862 of the relay 819 and at the same time separated from normally open contact 862. Because of this, the relay remains energized during the series of impulses and drops shortly after the end of the same.

Relay 816 closes in its xAMall on the normally closed contacts controlled by the contact spring 854, the circuit for the Rotary solenoid 827. This responds and brings the switching arms of the first group selector with the first contacts of the selected contact row and opens at the same time on its breaker contact 828 the circuit of relay 817.

ίο The following free choice is now known Way in front of you until there is a free continuing connection line in this row of contacts is found, e.g. B. the line with wires 92 to 94. Now the relay speaks 821 in series with relay 817, separates earth from the contact at contact 875 862 of relay 819 closes a holding circuit for the upper one at contact 871 Winding of the relay 819 and switches the incoming ones to its contacts 872 and 878 Speech lines to switch arms 879 and 881 through. Now lies over the line 897 and through the contact 872 battery to the switch arm 879, while earth through the Contact 878 is applied to the switching arm 881. This will make the surge receiving relay 107 of the second group selector (Fig. 2), which excites those described above Initiates switching operations.

The second group selector is set in a known manner by the next surge series transmitted by the surge memory, whereupon the connection is completed by setting further group and line selectors, e.g. B. via the group selector shown in Fig. 3 and the line selector (Fig. 4), with the requested subscriber station B is brought about. The switching through in the second and third group dialers and in the line dialer takes place in the manner described above. In the surge storage (Fig. 10); the relay 939 responds after all the series of current impulses required to establish the connection have been sent out and grounds the line 934 '. This is connected to the relay 820 of the first group selector (Fig. 9) via the switching arm 930 ', contact 924', line 895. The relay 820 responds and closes a holding circuit for itself at the contact 866. The speech circuit is closed at the contacts 864 and 870, whereby the impulse wire and earth are separated from the contacts 864 and 870 at the same time. At contact 869, relay 820 applies earth to line 894 and disconnects it from line 896, whereby relay 903 of the memory selector drops out and closes the following circuit for tripping magnet 907 of the same: earth, contact 869 of relay 820 (Fig. 9 ), Line 894, contact.

928, head contact 906, winding of the tripping magnet 907, battery, earth. Of the Memory selector is now returned to the rest position in a known manner, in which the circuit of the release magnet at head contact 906 is interrupted. At contact 926 of relay 903 earth is from Switching arm 931 and thus from the winding of the trigger relay 940 of the surge memory separated, so that this falls off and the triggering of the switching devices of the surge storage device brings about.

In the first group selector (Fig. 9), when relay 820 is triggered, the contact 865 the holding circuit of relay 819 is open, which drops out and at its contacts 861 and 863 relays 814 and 815 with the outgoing voice lines in connection.

When reporting the requested participant, as described above, in the second group selector (Fig. 2) the high resistance 115 from the bridge between the Speech wires switched off, whereupon the relays 814 and 815 (Fig.9) respond and the relay 814 at contact 851 the following circuit for relay 816 closes: earth at contact 848 of relay 813, resistor 829, Contacts 868 and 851, head contact 825, winding of relay 816, battery, earth. At the Contact 856 the relay 816 shorts the contact 851 of the relay 814, whereby a Holding circuit for relay 816 closed regardless of the state of relay 814 is. At contact 854 of relay 816, earth is connected to contact 874 of the test relay 821 applied to the counting wire 833, so that the counting magnet of the calling station is operated.

If the requested subscriber hangs his handset after the end of the conversation, see above relays 814 and 815 drop out. It will then the receiver at the calling subscriber station also hangs up, so the relay 812 de-energized and opens the circuit of the delay relay 813 at contact 846, which after a short time drops and the holding circuits of the various relays that are still operated open. The tripping magnet is activated via contact 849 822 excited, which returns the first group selector to the rest position.

Although the talk capacitors are not using while making a connection the switching arms 879 and 881 of the first group selector (Fig. 9) are connected, as that of the group selector shown in Fig. 1, the first-mentioned group selector can but to establish connections to a two-wire exchange via a second group selector, e.g. B. the

shown in Fig. 6, because the .Stromimppeicher the relay 820 excited after sending out all series of current impulses, causing the transmission of a busy signal or other monitoring signals to the calling point is made possible.

This group selector can also be used for connections in which the speech wires have to be switched through without the interposition of capacitors or feed bridges. For example, if a connection is made to a callback dialer, e.g. B. the one shown in Fig. S, then after occupying this selector, the battery is applied to the blocking wire 405 via the low-resistance winding of the relay 414 (Fig. 5) as soon as the calling subscriber has his handset after sending the desired series of current impulses hangs up. It should be noted that in this case the relay 812 (Fig. 9) and 845 drops battery is separated at the contact via the winding 814 of the switching arm 879, caused thereby further ² S switching operations described above in the recall voters. In the first group selector, the insensitive relay 811 is energized when the battery is applied to the blocking wire 405 in the callback selector (Fig. 5) and closes a holding circuit for its upper winding at its contact 842. At contact 843 the relay 811 opens the circuit for the tripping magnet 822 and switches the speech wires through at its contacts 841 and 844 and the capacitors and supply bridges off. Such a connection is triggered in the manner described above, so that this does not need to be described in more detail. The mode of operation of the monitoring lamps 891 and 892 will be briefly described. When the group selector is occupied, earth is applied to the blocking wire 831, whereby the relay 818 responds and closes a circuit for the monitoring lamp 892 at contact 859 via contacts 850, 853 and 855. This lamp lights up until the relay 816 responds at the start of the lifting movement and is switched on again after the same and after the relay 816 has dropped out. The circuit for the lamp 892 remains closed until the relays 814 and 815 are energized when the requested participant reports. Then relay 816 is also energized and is in a holding circuit until the call is ended. If the requested subscriber station hangs up its receiver after the call has ended, before the calling subscriber station triggers the connection, a circuit for the lamp 891 is closed via the contacts 850, 853 and the normally open contact 855, which indicates that not both subscribers have yet initiated the release of the connection.

Was a connection established via the first group selector shown in Fig. 9 made to the workplace of a civil servant, the civil servant can pass the voter through Applying battery to the lower voice wire hold set, reducing the relay 815 is excited. This closes a circuit for the trip relay at contact 853 813 via contact 850.

If the memory selector (Fig. 10) does not find a free one in the desired row of contacts Impulse storage, the shaft contact 909 is closed at the eleventh turn, via which a busy signal from wire 910 via line 893 'and the contacts 860 and 870 is applied to the lower voice vein. The same happens when it is busy all connecting lines that can be reached via a desired row of contacts of the first group selector.

The bi-directional connecting line TL (Fig. 2) will be discussed briefly. This connection line can be occupied from both ends. When this connection line is occupied from the left end, it is, as described above, occupied via the contact 125 of the relay 103 at the other end. On the other hand, if the connection line TL is occupied via the contacts of the group selector indicated at the right end of the same in Fig. 2, the relay 101 of the group selector for incoming traffic responds via the normally closed contact 125 and disconnects its speech wires from the contacts 121 and 122 the busy connection line.

Claims (16)

Patent claims: i. Circuit arrangement for telephone systems with dialer operation and several exchanges, characterized in that the connection devices (first group dialers) or lines in the exchange of the calling subscriber (A) are assigned switching devices (relays 39 and 40) which are connected by connecting devices (group and line dialers) are so differently influenced in the desired exchange that they make switchovers through which connections between subscribers of different exchanges in which the feeders are arranged in different connection stages (z. B. in the group selector or line selector) are made possible. 2. Circuit arrangement according to claim ι for systems in which the Impulse receiving relay of the selector at the incoming end of a connection line is located between two exchanges in bridge to the incoming voice lines, characterized in that the Switching devices (relays 39 and 40) for producing the switching processes corresponding to the respective status of the connection can be brought into effect in various ways by changing the resistance of the bridge. 3. Circuit arrangement according to claim 2, characterized in that the change in resistance of the bridge over the incoming speech wires of the connecting line (TL) is under the influence of connecting devices (group and line selectors) downstream in the connection setup. 4. Circuit arrangement according to claim 2, characterized in that the Resistance of the bridge circuit closed via the incoming end of the connection line when switched off part of the winding of the surge receiving relay (107) is reduced will. 5. Circuit arrangement according to claim 2, characterized in that the loop circuit for the surge receiving relay (107) at the incoming end of the connecting line (TL) for each current surge to be transmitted by switching off the battery from the one voice wire (92) at the outgoing end of the connecting line (TL ) is interrupted, while earth is continuously connected to the other speech vein (94). 6. Circuit arrangement according to claim i, characterized in that the first number surge receiver (first group selector) in the exchange of the calling subscriber is assigned a switching means (relay 35), which the speech circuit only after Termination of the entire rush current closes. 7. Circuit arrangement according to claim ι for systems in which connections between subscriber stations of a company management via callback dialers (Fig. 5), characterized in that switching devices (relays 31) are brought into effect in the first number surge receiver, which the capacitors and supply So bridge (relay 32, 39, 40) switch off and the incoming speech wires (17 and 19) directly to the speech lines (89 and 91) of the outgoing connection line. 8. Circuit arrangement according to claim 7, characterized in that the Switching from an insensitive relay (31) in the first number current surge receiver is brought about, which is excited via a low resistance in the recall dialer. 9. Circuit arrangement according to claim 8, characterized in that the Changeover relay (31) is connected between earth and the blocking wire (51) and by applying from the battery through a low resistance winding (414) to the Blocking wire (405) of the callback dialer is made to respond. 10. Circuit arrangement according to claim 7, characterized in that After setting the callback dialer, the current surge receiving relay (412) in the bridge to the speech wires (404, 406) the same is switched so that it acts as a feed bridge for the participants of the Company management serves. 11. Circuit arrangement according to claim 2, characterized in that for monitoring the switching means (relays 39 and 40) a high resistance (115) is switched into the bridge at the incoming end of the connecting line (TL). 12. Circuit arrangement according to claim 11, characterized in that the high resistance (115) in the bridge at the incoming end of the connecting line (TL) when reporting the called subscriber is switched on and the circuit of a delay relay is opened, which after its drop the resistor (115 ) switches off again from the bridge. 13. Circuit arrangement according to claim 11, characterized in that the Switching means (relays 39 and 40) at the outgoing end of the connection line circuits for monitoring signals Control (lamps 26 and 27) differently depending on the status of the connection. 14. Circuit arrangement according to claim 13, characterized in that the Circuits of the monitoring signs when occupying the connection devices (first group selector) during the Current impulse delivery and at the end of a call can be changed. 15. Circuit arrangement according to claim 13, characterized in that the iao Switching means (relays 39 and 40) are operated by monitoring currents, which are sent out by downstream switching means (group or line selectors) will. 16. Circuit arrangement according to claim 13 for systems in which the Impulse discharge and the transmission of the monitoring signals over the same wires takes place, characterized in that after the termination of the current impulse delivery switching means (Relays 35 and 36) become effective, which switch the monitoring circuits. In addition 3 sheets of drawings Berlin, printed in the ReichsdruCkerei