DE291960C - - Google Patents

Description

IMPERIAL

PATENT OFFICE.

The invention relates to a circuit arrangement in central switches for exchange line, Branch and private branch traffic, in which in a known manner the control the final signal in the central switch or to prevent premature final signaling after the office serving relays are connected to the connections of the office jacks, so that the pairs of cords are kept free from these relays

ίο are.

According to the invention, this is thereby achieved in a particularly simple and expedient manner achieved that a relay lying on a connection of the office jack of the central switch when inserting the interrogation plug of the central switch into the latch via the normally closed contact a second relay lying on the same connection of the office jack and a final signal of the central switch is excited and in a manner known per se a bridge containing a choke coil in the exchange line switches on to the final, signaling in the office when continuing the Exchange connection through the cord pairs to a call station until the end of the to prevent the call being recorded.

In the drawing, a circuit arrangement produced according to the invention is illustrated schematically in one embodiment. . '. . Once the query plug ASt of the central change-over switch is inserted in one of the connected to the central battery office through a line 1, 2 pawls AK, a current from the + pole flows through the normally closed contact 3 of a relay Ru, d via a relay Ri, line 4, the body of the Jack AK, a tail lamp SLi or a resistor Wi shunted to this lamp and a line 5 to the - pole of the battery, so that the relay Ri is energized. The relay Ri has such a high resistance that the lamp SLi does not yet light up. The excitation of the relay Ri can also take place via a special wire in which the 'tail lamp SLi is not switched on.

When the relay Ri responds, a bridge is switched on in the exchange line 1, 2, which is formed by a line 6, a line 7, the contact 8 of the relay Ri and a choke coil D. Instead of a choke coil, another means influencing the final signaling after the office can be switched on in the bridge.

By inserting the connecting plug VSt into the jack NK , a connection between the office and a speech station (extension) N authorized to communicate with the office is established. As soon as the receiver is picked up at the extension N , a relay NAR is excited in a known manner by the current + pole, NAR, N, NAR, - pole. When this relay responds, a circuit comes from the + pole via the normally open contact 9 of the relay NAR, resistor W, c wire

of the pair of cords, contact 25 of the speaking ·, switch SÜ, a high-resistance relay Rm connected to the c-spring of the jack AK , a low-resistance relay ATr connected in series with this relay, which can also be connected in parallel to the relay Rm , to the ■ —Pol established. The resistor W reduces the current flowing through the relays Rm and ATr to such an extent that only the high-ohmic relay Rm responds, while the low- ohmic relay ATr remains in the rest position. When relay Rm responds, relay Rn is also excited by switching the high-resistance winding 10 of this relay via + pole, normally open contact n of relay Rm, winding 10, line 4, tail lamp SL ₁ or resistor Wi, line 5 and -pole will. The resistance of the winding 10 is so high that the tail lamp SLf does not light up even now. The winding 10 can also be connected to the ■ pole via a special wire in which the tail lamp SL / is not switched on.

When the relay Ru is energized, its contacts 12 and 13 are closed. A holding circuit is established via contact 12: + -Pol, 12, io, 4, 51 / or Wi, 5, -Pol for relay Rn . By closing the contact 13, a circuit is prepared which, in the manner described below, lights up the tail lamp SLi after the conversation has ended.

When the armature of the relay Rn is tightened, the relay Ri is also de-energized by opening the contact 3, so that the bridge 6, 7, 8, D is interrupted by opening the contact 8. When the relay Rm responds , however, a new bridge, also containing the inductor D , has been switched into the exchange line 1, 2, which bridge is formed by the line 6, the contact .14 of the relay Rm, a line 15 and the inductor D.

If the receiver is attached to extension N after the call has ended, the relay NAR is deenergized. As a result, the relay Rm is de-energized by opening the normally open contact 9 of this relay. When the relay Rm is de-energized, the bridge 6, 14, 15, D connected to the exchange line is interrupted by opening the contact 14, so that the final signal is given in the office. In the present circuit there is therefore a direct final signaling, dependent on the extension N, after the exchange. When the normally closed contact 16 of the relay NAR is closed, a circuit comes from the + pole via contact 16, a line 17, a contact 18 of the pawl NK, body d of the pawl NK, a tail lamp SL // or a resistor Wn and the line 5 after the - pole so that the tail lamp SLu lights up. In addition, the tail lamp SLi is made to light up by de-energizing the relay Rm by a circuit via + pole, normally closed contact 19 of the relay Z? ///, contact 13 of the relay Rn, a low-resistance winding 20 of this relay, line 4, body d the office handle AK, tail lamp SLi, line 5 and -Pol is closed.

When the two lamps SLi and SLu light up, the end of the call at the extension N is indicated to the user of the central switch, so that he can now disconnect the connection to the jacks AK and NK. In the case of communication between an extension N and the office, the tail lamp SLu could serve only to give the final signal to the central switch. The tail lamp SLi acts mainly as a control sign for the correct operation of the relays of the central switch connected to the office handle.

By the switching on of the choke coil D containing bridge 6, 7, 8, D, or 6, 14, 15, D i in the exchange line, 2 premature signaling circuit according to the Official is prevented.

As soon as after inserting the plug ASt into the office latch AK the establishment of the connection of a call station (private station) Pr not authorized to communicate with the office is attempted by inserting the plug VSt into the latch PrK , there comes in the c-core the jack Pr K lacks a resistance corresponding to the resistance W , a circuit is established from the ■ pole via ATr, Rhi, c-wire of the pair of cords, c-wire of the jack PrK directly to the + pole. The current flowing through the relay ATr is strong enough to make this relay respond. The exchange line i, 2 is therefore separated in the contacts 21, 22 of the relay .ATr , so that no traffic between the office and the private station Pr is possible.

The activation of the relays Ri, Ru, Rm, ATr in the connections of the AK office jack offers the advantage that the lines are shortened and the switching of the central switch is significantly clearer compared to known devices in which relays that have similar effects as the relay Ri Exercise, Ru, Rm, ATr , lie in the pairs of cords and, because of the limited space under the table top carrying the pairs of cords, must be arranged at a certain distance from this table top.

The extension N and the private unit Pr can be brought into connection with one another in the usual way by inserting the plugs ^ 4Si, VSt into the pawls NK, Pr K. The call sign for the desired part

subscriber is given in a known manner by a ringing current flowing over the line 23, 24 as soon as the speech switch SU is turned over in a corresponding manner.
At central battery offices, it is advisable to take precautions to prevent erroneous ringing current from being sent into the exchange line. To this end, trim Schaltungsan in the present one all line pairs common isolation relay RTr is provided which has a significantly higher resistance than the relay Rm- If the plug FTSI introduced into the official pawl AK and Sprechumschal- ter SU folded in the Rufstellung, so a circuit comes from the + pole via relay RTr, line 26, contact 27 of the speech switch SU, the right-hand part of the c-wire of the pair of cords, c-wire of the AK office jack, relay rest relay ATr after the -— pole. The relays Rm and ATr receive so little current that they remain idle. The relay RTr responds on the other hand and separates the ringing current line 23, 24 at its contacts 28, 29, so that no ringing current can be sent into the exchange line. The RTr relay can also be controlled using a special wire in the pair of cords instead of the c wire.

Claims (4)

Patent Claims: i. Circuit arrangement for central switches for exchange line, branch and private branch traffic, characterized in that a relay [Rj) lying on a connection of the office jack [AK) of the central switch when inserting the interrogation plug [ASt) "of the central switch into the jack [AK) via the normally closed contact (3) is of a second, located on the same terminal of the Official latch relay [Rn), as well as a final sign [Sl ₁₎ of the central switch energized and containing in known manner a choke coil [D) bridge (6, 7, 8, D) switches on the exchange line in order to prevent the final signaling in the exchange when the exchange connection is continued through the pair of cords to a telephone station until the call recorded by the telephone station is ended. 2. A circuit arrangement according to claim 1, characterized in that after introducing the interrogation plug [ASt) into the office jack (AK) and introducing the connec tion plug [VSt) into the jack [NK) of a call station [N) when the listener is suspended from this call station . ah a connection of the office jack [AK) lying third relay [Rm) is excited, which by closing a circuit (+ -Pol, 11,10 of R _n , 4, d, SL ₁ , Wj, 5, -Pol) through the second relay [Rn) the interruption of the first, the choke coil [D) containing bridge (6, 7, 8, D) causes, at the same time a new, the choke coil [D) containing bridge (6, 14, 15, D) in the exchange line (1, 2) switches on to prevent premature termination signals in the office. 3. Circuit arrangement according to claim 1 and 2, characterized in that when the handset is attached to the intercom connected to the office [N) the third relay [Rm) 'is de-energized, whereby on the one hand in a known manner by separating the choke coil [D ) containing bridge (6, 14, 15, D) the final signal is given after the office and on the other hand via a normally closed contact (19) of the third relay [Rm), a working contact (13) of the second relay [Rn) and, a low-resistance winding (20) of the last-mentioned relay, a circuit that sets the final character [SLj) in the central switch comes about. 4. Circuit arrangement according to claim 1 to 3 for central switch at central battery offices, characterized by a high-impedance relay [RTr) which is common to all pairs of cords [ASt, VSt) of the central switch and has only a single winding, which after inserting a connecting plug [VSt) of the Central switch in an office jack [AK) is excited when the voice switch [SU) is moved into the Rufstellurig and interrupts the ringing current line (23, 24) so that no ringing current can be sent into the exchange line (1, 2). 1 sheet of drawings.