DE951456C - Circuit arrangement for telephone extension systems with dialer operation and subscriber busy lamps - Google Patents

Description

Circuit arrangement for telephone extension systems with dialer operation and subscriber busy lamps. The invention relates to a circuit arrangement for telephone extension systems with dialer operation and assigned to the subscribers Busy lamps.

For such arrangements, it is known to use the busy lamp on the Switch on the normally open contact of the isolating relay. With such an arrangement so the lamp is always switched on when the isolating relay is energized. is In such a system a subscriber interception circuit is provided in which after Release of the 'house connection routes, z. B. hang up the receiver of the called party Call station or after release of the connection devices in the event of a loop. or malfunctioning connection devices, the call relay is brought to waste and the isolating relay via the loop closure or via the loop of the participant, who has not yet hung up his phone is kept excited, and so it is the busy lamp light up during the capture state. The officer, the one arriving Establishes an exchange connection to a subscriber, is then not informed about whether the call station is busy or in the catch state.

The invention aims, with simple means .the occupied state and to distinguish reception status. This is achieved by the fact that it is busy the Subscriber circuit the call and the cut-off relay are energized and have a normally open contact of the call relay and a normally open contact of the isolating relay the busy lamp of the intercom is switched on.

The invention achieves that the subscriber busy laanpe only when the call and cut-off relay has been addressed, i.e. only when the line is actually busy is switched on. In the catch state, in which only the isolating relay is energized, takes place no activation of the busy lamp. Therefore, if the officer has an incoming office connection to a call station that is busy, the officer recognizes the When the busy lamp is switched on, it clearly indicates the busy status. Becomes the trunk connection made to a position in the capture state in which the busy lamp is not on, the officer recognizes by the lighting up of the monitoring lamp of the exchange line in the busy tone rhythm alone that the desired intercom is in the catch state is located.

In the drawing, an embodiment of the invention is shown. Internal connections within the private branch exchange run via the AS-LW selector. Exchange connections are established in the outgoing and outgoing direction via the exchange dialer AW. When the system is started up, a circuit for the thermal relay Th2 is established by switching on the battery. +, Ih, 2v1, 3k1, 4b; Th2, -. (1) After a certain time has elapsed, thermal contact 5 th2 is closed and relay B is switched on.

+, I h, 2 v 1, 3 k 1, 5 th 2, B, -. (2) By opening the contact ¢ b the circuit (i) for: the thermal relay Th2 is opened. A front contact 5 th2 independent holding circuit is established for relay B.

+, Ih, 2v1, 3k1, 6b, B, -. (3) As long as the exchange line is free, relay B is energized and the stimulus circuit for relay R is prepared via contact 7b.

Internal connection If the subscriber to station N requests one Connection with a subscriber of your own exchange is done by picking up of the handset the call relay R i switched on.

+, 8 t, intercom N, 9 t, I R i, -. (4) By contact ior i becomes the calling station is marked on the call finder AS. Through relay R i, that Relay K switched on.

+, IIYI, 124 13C1, K, -. (5) Relay K gives the call seeker AS the incentive to adjust to the calling station. When the call seeker AS reaches the call station N, the following circuit is established via the test arm c of the AS: +, i8 tr i, C i, switching arm c-AS, Io ri, II RI, 14t or 15 r I, I In the above Circuit, relay R i is kept energized and relays T and C i are made to respond. The AS is shut down by relay C i and the incentive line to one via contact 16c i. second AS switched. Opening the contacts 8 t-9 t interrupts the call circuit (4). The busy lamp BL of the call station N is switched on via the following circuit +, IIYI, 17 t, resistor. W, lamp BL, -. (7) The line selector LW is set in a known manner by dialing the subscriber numbers.

If the conversation is ended and the called subscriber first hangs up his receiver, the line selector LW is brought to the rest position, the contact 18 tr i is temporarily opened and the circuit (6) is thus interrupted. Relay C i releases the call seeker AS. The relay R i also drops out. For the relay T, as long as the receiver is picked up at the call station N, the following holding circuit is established: +, ZK, 19 k, II T, 2o r 1, z 1 t, call station N, 22 t, 23r1, I T, - . (8) When the relay R i drops out, the circuit (7) of the busy lamp BL is switched off. As long as the subscriber interception circuit exists, that is, as long as relay T is energized, the lamp BL is not switched on either.

A busy signal BZ is switched on in the aforementioned circuit, by which the participant of the station N asked to hang up the receiver wind.

In the holding circuit of relay T, relay LK is switched on. This Relay LK closes the circuit for thermal relay Th.

+, 24an, 251k, Th, -. (9) After a certain time has elapsed, the thermal contact 26 th is closed and the relay K is switched on.

+, 24 an, z6 th, K, -. (I0) Relay K remains independent of contact 26 th via contact 27k. The holding circuit (8) of relay T is opened at Kontakf ig k and relay LK is switched off. The relay T is held via contact 28 k. If the participant of the intercom station N hangs up, the holding circuit for relay T is interrupted, which means that the contacts are returned to the rest position.

The interruption of the circuit (io) for relay K is in any case when a call incentive is present in the private branch exchange, wherein (the get an unillustrated relay for addressing and opens the circuit (io) of the relay K at the contact 24an.

Connection via the message line If the subscriber of the intercom N wishes a connection with the branch officer Ba via the message line, the line selector LW must be set to the message line connection i after the call finder AS has been set. The AM call relay of the message line is energized in a call rhythm (5 sec). This relay closes the busy lamp BL via contact 29 on, switch arm d-LW - in position i and switch arm d of the AS. The lamp BL is therefore switched off in the ringing rhythm and thus indicates that the subscriber of the telephone station N wants a connection with the extension officer. The extension officer can connect to the message line connection in a known manner. The call disconnection takes place with this connection. The AM call relay is no longer activated. The lamp BL now lights up continuously.

When the connection is terminated, it is triggered in the manner described Way. Outgoing trunk connections Outgoing trunk connections are made by choosing the Outside line code 2 initiated.

If the exchange code is dialed by a semi-authorized intercom station, the relay.G is switched on via the test arm c of the line selector LW after an authorization test relay H i, not shown, has come into effect. The authorization test relay H i opens the contact 3o h I and thus prevents the transmission of incentives to a free exchange dialer AW. Via minus 3 i bh, 32 h I, switch arm d of the LW in position .2 and switch arm d of the AS, the lamp BL is short-circuited by contact 3 i bh in the busy tone rhythm (i-sec) and switched off during this time. When the lamp BL lights up in the busy tone rhythm, the officer recognizes that the subscriber of a semi-authorized intercom wants an exchange connection. If a free exchange line is available, the officer causes the authorization check relay H i to drop. The relay R is switched on.

+, Sole, 33g, 7b, R, -. (II) The IUL monitoring lamp is switched on by relay R.

+, Lamp ÜL, 68 h, 67 r, -. (I2) A bridge is placed between the wires of the exchange line via the contacts 69r, 7o b, through which this line is identified in the office as: busy. .

The relay R switches the winding M II of the stepper motor for the Exchange dialer AW one.

+, 34y, 3 5z, 36m2, M2, -. (I3) The motor starts to turn. The circuit (i3) is opened at the contact 36 m 2 and the winding M i is switched on via the motor contact 37 m: +, 34r, 35z, 37mI, MI, -. (14) The windings M 2 and M i of the motor are switched on alternately until the exchange dialer AW checks the calling station. In this case the following circuit is established: K + pole of the external voltage IC, Pr, 38 y, switching arm a-AW, AS, LW, code number connection 2, TB, K-pole of the external voltage. (i5) Relay PR closes the braking circuit of the motor via contact 39 pr when the motor contact 36m2 is closed and thus the exchange dialer AW is shut down.

The relay TB of the code number connection causes the release and tripping of the LW and AS. The following blocking circuit is established via the test arm c of the exchange dialer AW: +, 40c, III C, q.1 tr, switching arm c-AW, II R, i 5 ri, IT, -. (i6) When relay C responds, relay S is switched on.

+, II S, II X, 42 as, 43h, 44c, 45r, 46 p I, 47c, 48 h, 49 as, IX, IS, -. (I7) Relay S switches on V i.

+, 50 s, V I, -. (I8) Relay V i opens the holding circuit (3) of relay B at contact 2v i. Relay B drops out. The circuit (ii) at contact 7 b is opened and the stimulus line is switched over to contact 5 1 b to the occupancy relay of a second exchange dialer. The stimulus line has already been opened at contact 33 g as a result of the tripping which is caused by the relay TB. The EIL lamp remains switched on via contact 7 1 b . The following holding circuit now exists for the feed bridge relay S: +, II S; II X, 42 as, 43h, 44c, 52r, switch arm b-AW, call station N, switch arm a-AW ,, 53t 47c, 48h, 49 as, IX, IS, -. (I9) Via contact 54s. is the. External line switched through.

The participant can choose to hire the voters of the office kick off. The current surges are received by the relay S and through contact 54s transferred to the trunk.

If the connection via the exchange line is ended, the circuit (z9) of the relay S is opened by hanging up the receiver at the intercom station N. The relay S drops a # b and interrupts the circuit (i8) for relay V i at contact 5o.s. During the release time of the relay V i, the relay V 2 is switched on. +, 1 h, 55 v 1, 56 s, T12, 57 tr, -. (20) Relay T13 is switched on by relay T12.

+, 58v2, 1V3, -. (21) If the relay V i has returned the contacts to the rest position, the excitation circuit (2o) for relay V z at contact 55 v i is interrupted and the excitation circuit (i) for the thermal relay Th2 is switched on via contact 2v i. Relay T12 interrupts the excitation circuit (21) for relay T13 at contact 58v2. If relay T1 i has dropped out, relay T13 of relay Tr is switched on during the drop-out time.

+, 59v 1, 60v3, ITr, -. (22) The relay Tr is maintained via the following circuit +, 61 tr, II Tr, selector contact 62 kaw; +. (23) The relay Ph, which is parallel to relay Tr, is also switched on.

The relay Tr opens the circuit (16) on contact 41 tr via the switch arm c of the AW. Relays C, R and T drop out. After the relay C has dropped, it is with the addressed Relay PH the winding M2 of the motor switched on.

+, 63c, 64p, 65p1, 66h, 35 2 , 36m2, M: 2, -.

(24) The selector begins to turn, opens contact 36m2 and then flips contact 37 m i. The winding M i is switched on. +, 63c, 64p, 65 pi, 66 ph; 35z, 37m 1, M i, -. (25) The windings M i and M2 are switched on alternately and the dialer continues to rotate until it has reached the rest position. In the rest position .des Office dialer AW the circuit (23) for the relays TR and PH at contact 62 kaw is opened and the circuits (24, 25) of the motor windings M i and M 2 at contact 66 ph are interrupted.

If, after the relay V i drops, the thermal relay Th2 in the circuit (i) effective; in this way, the circuits (2) and (3) are restored one after the other. Relay B is energized and indicates the free state of the trunk line.

Incoming exchange connection If a call is coming in via the exchange line, so the A-relay is excited by the ringtone of the office.

If the public exchange dialer AW is not in its rest position by z. B. has been rotated by hand, then the call relay A of the exchange line in conjunction with the voter contacts in the working position of the voter AW is first returned to the rest position. The relay T13 is switched on by the call relay A. +, 72 kaw, II T13, 73 a, 74n, 75 as, -. (26) Relay Tr in circuit (22) is energized by relay T13. The holding circuit (23) is then established. for relay Tr. Relay PTa, which is switched on in parallel with Tr, returns the selector AW to the rest position in the manner already described. If the selector AW has reached the rest position, the relay H is switched on.

+, 76 tr, IH, 77 a, 78 kaw, -. (27) The relay H is kept in the following circuit: +, 76 tr, IH, 79 p, 8o h, 81 w, 82 as, -. (28) The holding circuit (3) for relay B is opened at contact ih. Relay B causes the trunk to be identified as busy. The stimulus line is switched over to the starter relay R of a second exchange dialer via contact 51b.

The call lamp AL is switched on.

+, Lamp AL, 83 tr, 84 fl, 85'w, 86 h, -. (29) To answer the call, the officer presses the exchange key AT assigned to the calling exchange line.

The relay AS is guessed.

+, HU, AT, I AS, 87r, 88z, -. (30) After releasing the AT key, the following holding circuit is established for the AS relay: +, HU, AT, 89 as, II AS, -. (31) By opening the contact 82 as becomes. the holding circuit (28) for relay H is disconnected and the monitoring lamp ÜL is switched on.

+ Lamp ÜL, 68 h, 71 b, -. (32) Relay AS keeps lamp AL switched on via contact 126 as. and the device BA is connected to the exchange line via the contacts 9o as-91 as. The relay S is energized. +, II S, II X, gi as, loop of the apparatus BA, 9o as, IX, IS, -. (33) Relay S energizes relay V i in circuit (18). At contact 92v i the call relay A is switched off by the exchange line. The relay S has switched through the exchange line with contact 54s. The officer can speak to the calling office participant and find out the desired intercom from him. If the participant of intercom N is desired, the officer has to press the connection button VT. The differential relay X in the circuit (33) is excited. The relays VS and W are switched on. +, HU, AT, 89 as, 9o x, VS, 57 tr, -. (34) Relay W is parallel to relay VS. This relay also brings the contacts into the working position. Relays VS and W are kept energized independently of contact 9o x via contact 91 vs. If the VT key is released, the differential relay X returns the contacts to the rest position. The relay K i is switched on by the relay W.

+, 92w, K i, 88z, -. (35) The relay K i bridges the pulse contact 54s with contact 93 hi, so that the subsequent current surges of the relay S are not transmitted to the exchange line.

By opening contacts 94vs-g5 vs and closing contacts 96vs-97vs the primary windings .des transformer Ue are short-circuited and thus the connection interrupted between the officer and the calling office participant. About the contacts 98vs-9gvs, the officer's machine is connected to the connection side of the exchange line.

The series of current impulses sent by the officer acts on the feeder bridge relay Being. When the relay S falls for the first time, the relay T12 is in the circuit (2o) switched on and remains during the series of impulses. The relay T12 switches the relay T13 in the circuit (21) on. With the pull-in, the relay T12 closes the winding M2 of the motor switched on.

+, ioov2, 36m2, M2, -. (36) The exchange dialer AW is set in rotation and thereby the contact 36m 2 is opened and then the contact 37m 1 is closed. Until the relay S responds again, the winding M2 of the motor is switched on via the following path: +, Ioov2, 101 W, IO2s, M2, -. (37) If the contact 37 m I is closed, the winding M i is switched on.

+, I00 v 2, 37 m I, M i, -. (38) At the end of the first pulse, relay S is energized again. The circuit (37) for winding M2 is opened at contact io2s. There is only the circuit (38) for the winding M i, so that the dialer continues to rotate. With the turning movement, the motor contact 37m I opens. As long as the relay S is energized again after the first interruption, the following circuit exists for the winding M i: +, 100v2, 35 2 , 1 0 3 A 10 4s, MI, -. (39) If, after opening contact 37m i, motor contact 36m2 is closed again, winding M2 in circuit (36) is switched on and thus selector AW is stopped.

If the relay S drops out due to the second pulse, the circuit becomes (3g) opened for the winding M i. There is only winding M2 in the circuit (36) switched on. The voter is thus rotated further. The control of the windings M2 and M i through the relay S is described until the end of the series of impulses in FIG Way done. After the end of the first series of impulses, the contact is 56 s open for a long time. The relay T12 drops out and breaks at contact 58r2 the circuit of relay T13.

If the exchange dialer AW gets through the first series of impulses on a Rest area, z. B. o, so remains. The relay T13 even during the pause between two Stress series excited.

+, 72 kaw, II T13, rectifier G1 i, switch arm d-AW in position 0, Ios vi, rectifier G12, -. (40) If the connection of the desired intercom has been reached after the series of impulses, the relay T13 drops out. The relay P is switched on. +, io6kaw, 107w, io8V3, iogs, P, iioc, iiitr, -. (41) Relay P switches on relay H. +, 76 tr, IH, i ip, ii 5 w, -. (42) Relay P; also switches on relay P1.

+, 116c, 117p, I Ph, -. (43) The following circuit is established for relay P i: +, I I2 p, PI, 113w, 86h, -. (44) A holding circuit is established for relay P i independent of contact I I2 p.

+, 127 p I, P 1, 113 w; 86 h, -. (45) The thermal relay Th 5 is switched on.

+, I27 p I, I28 wr, Th 5, 113w, 86 h, -. (46) The relay W lasts through its winding II. +, HW, 113w, 86 h, -. (47) If the intercom station N is free, the relays C, R i and T in the test circuit are energized.

+, 118 vi, I I9 p 1, II C, HIC, 41 tr, switch arm c-AW, II R i, 144 IT, -. (48) Relay C interrupts the circuit (43) of relay Ph at contact 116 c. Relay Ph drops out. The circuit (41) of the relay P is also opened at the contact i io c. The relay H is now on the following circuit +, 76 tr, IH, 79 p, 8o h, I 15 w, -. (49) The lamp ÜL is now switched on by relay C in the following circuit: +, lamp UL, 1 20 p I, I21 C, 122 ph, 123 rk, -. (50) Contact 123 rk is a cam contact of the call and signal machine, which is closed in a call rhythm (5 sec). The lamp ÜL is thus made to light up in the ringing rhythm when the extension is free.

The subscriber relays R i and T, which are excited in the circuit (48), switch on the busy lamp BL in the circuit (7). The following ringing circuit now exists for call station N: +, 124h, 44c, 52r, switch arm b-AW , call station N, switch arm a-AW, 53 r, 47 c, r25 h, II H, call current source. (51) The call station N is sent a ringing current at 5-second intervals. After mediating, the officer hangs up the phone. The circuits (31) and (34) are opened. The relays AS and VS drop out. The relay W remains excited via the winding II in the circuit (47). The holding circuit of the call lamp AL is opened at the contact i26as and thus the lamp AL is switched off. When relay AS drops out, the circuit (33) for relay S is interrupted. Relay S drops out and opens the circuit (18) of relay V i at contact 50s.

If the participant of the intercom N does not answer within a certain time, the thermal relay Th 5 switched on in the circuit (46) will switch its contact to the working position. The relay WR is energized.

+, Night switch N, 129 v 1, 130 th 5, WR, -. (52) Relay WR holds itself independently of contact 130 th 5 via contact 131 wr. The relay WR opens the circuit (46) of the thermal relay Th 5 at contact i28wr. After a certain cooling time, the thermal relay Th5 returns the contact to the rest position. The relay FZ is switched on.

+, N, i29 v 1, 132 th 5, 133 wr, I FL, -. (53) Relay Fl remains independent of contacts 132 th 5 and 133 wr via contact 134 fl.

When the relay Fl responds, the call lamp AL of the exchange line is switched on in the following circuit: +, lamp AL, 83 tr, 135 fl, 136 bk, -. (54) Contact 136 bk is a cam contact of the call and signal machine, which is closed in the busy tone rhythm (i sec). The call lamp AL lights up in the busy tone rhythm. Since at the same time the monitoring lamp ÜL in the circuit (50) - is switched on in the ringing rhythm, the officer recognizes that the intercom is free and has been called, but has not responded within a certain time. The officer is therefore able to precisely inform the subscriber calling via the exchange line. For this purpose, the officer presses the office key AT assigned to the exchange line. The relay AS in the circuits (30,31) and the relay S in the circuit (33) are excited. The relay S switches on the relay V i in the circuit (18). The relay V i interrupts the circuits (52) and (53). The relays WR and FL are returned to the rest position. The AL call lamp is continuously switched on in the holding circuit via contact i26as. The officer on the outgoing trunk will ask the calling party to repeat the call later.

In order to release the connection, the officer activates the common one Disconnect button T. The relay Tr is switched on.

+, Key T, 137 as, I Tr, -. (55) Relay Tr is in circuit (23) parallel to winding II of relay PH.

The relay Tr opens the circuit (48). Relays C, R and T drop out. The circuit (7) of the lamp BL is opened.

After the relay C has dropped, the windings M i and M2 in the circuit (24, 25) are switched on and lead the public exchange dialer AW back to the rest position in the manner described. When relay Tr responds, the holding circuit (49) of relay H opens. The relay H leads the contacts back to the rest position. When relay H drops out, the holding circuit (45) of relay P i and the holding circuit (47) of relay W at contact 86h are opened. The circuit (35) for relay K i is opened at contact 92 w. The relay P i opens the circuit 5o of the lamp ÜL at contact 12o p i. The flickering state of the lamp ÜL is canceled and switched on in the circuit (32): continuously lit.

If the officer hangs up the receiver, the circuit of the relay AS is opened. The circuit of the AL call lamp is switched off at the i26as contact. By disconnecting the officer from the exchange line to the contact 9o as-gi as the relay S is de-energized. Relay S interrupts the circuit (18) of relay V i. Relay Th, 2 is switched on in circuit (i) and causes circuits (2) and (3) to be established for relay B. Relay B unblocks the exchange line. The lamp ÜL is switched off at contact 71 b. If the subscriber of the call station N reports after the ringing circuit (51) has been established before the relay Fl is switched on, the counter-winding II of the relay H in the ringing circuit becomes effective and causes the relay H to drop out. The holding circuit (49) is opened. Holding circuits (45) and (47) of relays P i and W are never interrupted at contact 86 h, so that these relays return the contacts to the rest position. The relay W opens the circuit (35) of the relay K i at contact 92w. The monitoring lamp ÜL is switched on by dropping out the relay H via contact 68 h in the circuit (32) and hereby indicates the reporting of the desired intercom. Relay H switches the exchange line through via contacts 43h-48h. The relay S in the circuit (ig) is switched on. The relay V i is brought into effect by relay S in the circuit (18).

The subscriber of the intercom station N is the public subscriber calling with breath tied together. When the conversation is over, you can hang up or hang up the The circuit (i9) for relay S is interrupted by the handset at call station N. That Relay S drops out and causes the Release of the exchange line and the return of the exchange dialer AW to the rest position. Then relay B (circuits i to 3) is made to respond and through this relay B indicates the free state of the trunk line.

If the exchange dialer AW is set to the intercom stationN and this intercom station is currently busy, the R i and T relays of this intercom station are energized and the lamp BL in the circuit (7) is switched on. The test relay C of the exchange dialer AW cannot turn energized in the circuit (48). Likewise the relay P in the circuit (41). The monitoring lamp UL is switched on in the following circuit: +, lamp ÜL, 120P 1, 138 c, 136 bk, -. (56) The contact 136 bk, which is closed by the interrupter in the busy tone rhythm, also switches on the lamp UL in the busy tone rhythm. Because the busy lamp BL of the desired intercom N is switched on and at the same time the monitoring lamp ÜL lights up in the busy tone rhythm, the officer clearly identifies the busy state.

If the officer switches off from the exchange line by hanging up the receiver, the circuit (31) of the relay AS and the circuit (34) of the relay VS are opened by opening the hook switch HU. The relay W is kept in the holding circuit (47). By opening the contacts go as-9 i as the circuit (33) of the relay S is opened. The relay S drops out and interrupts the circuit (18) of the relay Vi at contact 50s. The circuit (41) of the relay P @ is interrupted at the contact iogs. The relay P causes the relay PH to drop out by interrupting the circuit (43). The waiting state of the exchange line is thus established. The relays H, W, K i and P i are excited and the Thermorel: ais Th.5 switched on parallel to relay P i.

If the participant of the intercom station N does not terminate the existing connection within a certain time, the thermal relay Th5 becomes effective. The circuits (52) and (53) for the relays WR and Fl are established and the call lamp AL of the exchange line in the circuit (54) is switched on. The AL call lamp flickers with the busy tone rhythm. Since at the same time the monitoring lamp UL in the circuit (56) lights up in the busy tone rhythm, the officer recognizes that the intercom N is still busy and has not yet answered.

Pressing the exchange key assigned to the outside line will activate the Relay AS in the circuits (30, 31) energized and thus the officer to the exchange line turned on. It becomes the relay S in the circuit (33) and the relay V i in the circuit (18). excited. The circuits (62, 53) turn on contact 129 v i interrupted and thus the relays WR and Fl returned to the rest position. The call lamp AL is switched on via contact i26as and lights up continuously.

The officer connected to the exchange line informs the calling person Participants that the desired intercom is currently busy. Wishes .the calling participant continues to wait, the officer switches off the trunk and the trunk will be put back on hold. If the calling participant renounces the connection, the officer in front of the Shutdown by pressing the disconnect button T. It will hereby trigger the connection devices carried out in the manner already described.

If the exchange dialer AW is set to intercom station N and the interception state is established for intercom station N by only energizing subscriber relay T, then, as already described, subscriber busy lamp BL is not switched on. The test circuit (48) of the exchange dialer AW cannot come into being due to the open contacts 14 t and 15 ri. Failure to respond to relay C initiates the same switching processes as when the desired intercom is busy. The lamp UL in the circuit (56) is made to light up in the busy tone rhythm: By the fact that the busy-. The BL lamp of the desired intercom does not light up and the UL monitoring lamp flickers with the busy signal rhythm, the officer clearly recognizes the state of the subscriber circuit. The officer can inform the calling station of this and take care of the removal of the interception circuit.

If you do not use the calling parts, you will have to wait again the release of the exchange dialer by pressing the disconnect key T in the described Way done.

If there is a connection between the telephone station N and the trunk line, the subscriber relays R i and T and the relays C, S and hi assigned to the trunk line are energized. If the participant of the intercom station N wishes to give the officer a flicker signal during the existing connection, the participant must press the Ta key for a longer period of time. The thermal relay Th4 is switched on. +, 139v 1, 140x, 141 fl, Th 4, 142 as, -. (57) The relay FZ is switched on by the thermal relay Th4.

+, 139 vi, 140x, 143 th 4, II FZ, -. (58) The relay FZ opens the circuit (57) of the relay Th4. A holding circuit is established for relay FZ independently of contact 143 tk4. .

+, 139v 1, 14O x, 144 fl, II F1, -. (59) The call lamp AL is switched on in the circuit (54) in which the lamp AL is made to light up in the busy tone rhythm. Since at the same time the monitoring lamp UZ in the circuit (3a) is switched on and burns continuously, the officer recognizes in a clear manner that a participant of the intercom connected to the exchange line wants the officer to be connected to the exchange line. After pressing the exchange key AT and the connection key VT, the officer is connected to the connection side of the exchange line via the contacts 98vs-99vs and can speak to the subscriber of the intercom IV.

By pressing the release button T, the officer can initiate the release of the exchange dialer AW and the renewed setting of the exchange dialer to another intercom. After the connection has been established in the manner already described and the officer has been disconnected from the exchange line, the triggering of the connection devices when the connection is established is dependent on the feeder bridge relay S.

Claims (1)

PATENT CLAIMS: i. Circuit arrangement for telephone extension systems with dialer operation and the busy lamps assigned to the call stations, characterized in that when the subscriber circuit is busy, the call relay and the disconnection relay are energized and the busy lamp is activated via a working contact of the calling relay (R i) and a working contact of the isolating relay (T) Station is switched on. See circuit arrangement according to claim i, characterized in that the subscriber busy lamp (BL) is switched on by the call relay (R i) and the isolating relay (T) of the subscriber circuit both for house connections and for office connections. 3. Circuit arrangement according to claim i, characterized in that when an incoming exchange connection is made to a free intercom (N) the subscriber busy lamp (BL) , switched on by the call relay (R i) and the isolating relay (T) and the monitoring lamp (UZ ) of the exchange line is lit up in the rhythm of the ringing. 4. Circuit arrangement according to claim 3, characterized in that the monitoring lamp (ÜL) of the exchange line is switched on by the test relay (C) of the office dialer. 5. Circuit arrangement according to claim i, characterized in that when an incoming exchange connection is made to an occupied call station (N) the subscriber busy lamp (BL) is already switched on by the call relay (R i) and the isolating relay (T) excited in the existing connection Monitoring lamp (UUL) of the exchange line is brought on in the busy tone rhythm. 6. Circuit arrangement according to claim i, characterized in that when establishing an incoming exchange connection and loading. The subscriber busy lamp (BL) is not switched on and the monitoring lamp (UL) of the exchange line lights up in the busy tone rhythm when the subscriber circuit is in the standing capture state (call relay R i dropped, isolating relay T energized). 7. Circuit arrangement according to claim 6, characterized in that, the catching state of the subscriber circuit (call relay R i dropped, isolating relay T energized) after triggering the connecting devices (AS-LW) and not hanging up the handset. established at the intercom and an acoustic busy signal is switched on for the participant of this intercom. B. Circuit arrangement according to claim i, characterized in that the subscriber busy lamp (BL) is switched on according to the choice of the message line, in the ringing rhythm and according to the choice of the office code by a semi-authorized body in the be @ set character rhythm. Documents considered: German Patent No. 540 446.