DE1233025B - Circuit arrangement for partially electronic small private branch exchanges with an exchange line and an internal connection network - Google Patents

Description

Circuit arrangement for partially electronic small private branch exchanges with an exchange line and an internal connection network The subject of the invention is a circuit arrangement for partly electronic small private branch exchanges with an exchange line and an internal connection set, the connection relay with the calling and / or via the individual subscribers and can be influenced by corresponding switching measures of these subscribers extension subscribers to be called are interconnected. In the previously used private branch exchanges of this type, which only work with relays, it is necessary to use blocking chains of the individual connection relays to ensure that the common internal connection satellite cannot be occupied by several,., I subscribers at the same time and that this is also prevented that -I can connect to another extension subscriber to an outside line that is already in use. These S- blocking devices in the form of contacts of the switching relays containing blocking and switching chains are often subject to malfunctions, so that it is precisely with these systems that double and cross connections can occur.

The invention eliminates the disadvantages of this known '. small private branch exchanges in that the switch relays are set via their associated bistable flip-flops that can be influenced by the respective assigned subscriber and are kept energized for the duration of the working state of these flip-flops until another switching measure is carried out by the respective subscriber, and that these flip-flops each have one of the remaining flip-flops influenceable, the simultaneous occupation of the trunk line or the internal connection set by several subscribers preventing blocking gate is connected upstream. In this partially electronic design of a small private branch exchange, the previously necessary blocking and exclusion chains are replaced by electronic components in the form of flip-flops and blocking gates.

An exemplary embodiment of the invention is shown in the drawing. It shows F i g. 1 the speech paths of a small private branch exchange with a maximum of six participants, an internal connection set and an exchange line, F i g. 2 the control devices of such a private branch exchange and Fi '- necessary for setting up an internal call. 3 the control devices necessary for the establishment of incoming and outgoing exchange calls.

Like F i g. 1 shows, the individual extensions Nl, N2 to Nn are assigned connection relays T1, T2, etc., via which the subscriber lines of these subscribers can be interconnected with the internal feed set containing the feed and pulse relay. In addition, the individual participants in F i g. 3 shown changeover relays Ul, U2 to Un, which cause the coupling of a subscriber line to the Amtsleituno, AL. In the subscriber connection lines there are differential relays XI, X2 , etc., which respond when the earth button is pressed on a call station and which serve to either interconnect the relevant connection line with the exchange line or to initiate the inquiry status when they become effective during an exchange call or at the end of the Query when picking up a call to couple the exchange line with the accepting subscriber. The extension subscribers are fed by the feed relay J for internal calls, while these subscribers are fed by the relay S for external calls. The call relay AR is in the exchange line to receive an incoming exchange call and forward it with its contacts to the respective desired extension.

The monitoring relay M, a delay relay, is attached to other relays V, the inquiry initiator relay H and a relay Y are provided.

The gate connections Tli to Tni, T4i to T6i and T71 to T91 in FIG. 2 and Tla to Tna, T4a to T6a in FIG. 3 are also provided for each participant. The bistable toggle switches BM1i to BMW or BM41 to BM6i (F 1 g. 2) and BM 1 a to BM na (F i g. 3) are also individual to each participant. The connection of the ringing current to the respective subscriber line to be selected is carried out by one of the ringing relay I, II to N in FIG. 2, the selection of which is a selection chain WK in a manner to be described.

Internal connection C If the subscriber loop is closed at a call station by unhooking the receiver, the assigned relay (7) responds. For example, if the subscriber Nl picks up his receiver, the relay TI speaks via + b, 1, Tl, t13, u12, Xl (I), m12, Nl, mll, X 1 (11), u 11, t 12, Wi, -.

Relay XI is not energized in this circuit because it is connected differentially. With the contact t 11 in FIG. 2, the bistable multivibrator BM1 i is reversed via the AND circuit T 1 i, thereby keeping the relay Tl energized via its winding II. The output al of the bistable multivibrator BM 1 i becomes negative, so that the AND circuits T21 and Tni are blocked. In this way, double occupancy of the internal connection set due to microphone units hanging out at the same time is prevented.

Via the contacts t12 and t13 the call station loop is connected to the inner path, i. H. to feed relay J, switched through. The feed relay J is energized and its contact i in FIG. 2 switches. Earth potential is removed from input E of timing element Z and relay B is switched on via output A. Contact b switches in FIG. 1 disconnects the starting circuit of the relay (7) and applies the busy signal BZ via a capacitor.

The dialing chain WK is set via the contact 1 and a pulse shaper JF by the impulses that now follow from the speech station Nl. Due to the delay of the timing element Z, the relay B remains energized during the impulse. After C in the setting of the dialing chain WK, the call switch relay of the selected point, for example relay II, responds. At the same time, the bistable multivibrator BM5i is activated at this point. Via its output, the multivibrator MV1 is switched on, which energizes the relay R in a ringing rhythm, which now switches on with its contact r (Fig. 1) in the ringing rhythm alternating current to the working side of contact 2 of the Rufanschalterelais II of the desired extension N2 . The selected call station is called in this way, and when you hang up your receiver, the relay T2 in the loop circuit already mentioned responds. With the contact t21 via the AND circuit T 5 1, which bypasses the locked AND circuit T21, reversing potential is switched on to the left input of the bistable multivibrator BM2i of the desired call station N2 , so that it is reversed and the relay via winding II T2 to respond. As a result, the called station is now connected via the contacts t 22 and t 23 with the feed relay J and thus with the calling subscriber. At the same time, via contact t21 and the right input of the bistable flip-flop BM51, this flip-flop is reset to its original position and thus the shutdown, the multivibrator MY1 and the de-energization of the relay R. The speech state is now established. If both units hang up their receiver at the end of the call, the feed relay J drops out. The contact i in FIG. 2 returns to its rest position and applies ground potential to input E of timing element Z. After a delay, which is slightly longer than a dial pulse pause, the relay B is made to drop out by the timer Z and a trigger pulse is given via the output L to the extinguishing pulse generator LJ and thus a reset of the selection chain WK and all actuated bistable multivibrators in their initial position . The relays assigned to them then also drop out.

In the above, it was assumed that the selected station N2 is free. On the other hand, if this is already occupied, and because only one Internet record is provided, it can only be an occupation by an external call, point U 2 '( FIG. 3) is identified by positive potential. After the setting of the selection chain WK, the bistable multivibrator BM8 is reversed via the AND circuit T81 and the OR circuit 01 and at the same time the setting of the selection chain WK is deleted. As a result, relay II cannot respond while relay R is continuously energized via the output of bistable multivibrator BM8 and thus transmits a busy signal to the calling station. The pulse shaper M is blocked via the same output of the bistable multivibrator BM8, so that a pulse is not possible. The attempted connection is released when the subscriber is hung up in the manner described above.

Outgoing exchange connection C If the subscriber loop is closed by picking up the receiver in order to initiate an outgoing exchange connection in the intercom, an internal record is initially occupied, as described above. If the internal set is already occupied, the intercom will receive a busy signal.

To seize the exchange line, it is necessary to press an earth button on the subscriber station. As a result, in any case, i. H. Relay X via its winding 11 to respond both when the indoor set is free and when it is occupied. If the exchange line is free, the contact xll and the AND circuit T la in FIG . 3 the bistable multivibrator BM1a is controlled. This tilts into its working position and causes the relay U1 to respond via output a. The AND circuits T2a and Tna are blocked via the output a, so that it is no longer possible for the other positions to seize the exchange line. The contacts u 11 and u 12 in FIG. 1 switch on the subscriber line to the exchange transmission. The flip-flop F l is also reversed via the output of the AND circuit Tla via a pulse detector JF, the output of which a becomes negative.

The subscriber speech loop is used to excite the feed relay S, so that the office loop can be switched through via the contact sl. The contact sl follows the impulses of the intercom during the subsequent dialing of the exchange number by the calling subscriber. When the impulse is generated, the contact s2 in FIG . 3 via the timer Z 1, the relay Y is switched on as an auxiliary relay whose contact v short-circuits the exchange transmitter in order to avoid pulse distortions.

If the exchange transmission is already occupied by another station when the earth button is pressed at a subscriber station, the relay U cannot respond to this station, as mentioned, because the corresponding gate circuit Tla to Tna is blocked. In this case, relay X is linked via contacts x12 and u13, and the subscriber also receives the busy signal in this circuit. If the office requesting the office is authorized to listen in and if the listener does not hang up within a certain time, the monitoring relay M responds via the timer Z2 controlled by the AND circuit T1a. Contacts m11 and m12 switch the relay into the holding circuit of the call station, while contacts m13 and m14 switch on the eavesdropping transmission. The X relay drops out after the monitoring transmission has been switched on via contacts m13 and m14. Inquiry and transfer If the intercom making an external call wants to make an inquiry, it must press its earth key again. When the button is pressed, the relay X is activated again via the winding II. The contact x 11 applies again to the AND circuit Tla on the assumption that the exchange call was established by the extension Nl, ground potential through which the flip-flop Fl is reset via the pulse shaper JF. As a result, the output a of this flip-flop becomes positive, and since the second input of the AND circuit T10a also has a positive potential due to the switching of the contact s2, the relay H is switched on via the driver stage RTr. The contact hl forms the holding loop of the trunk line AL, while the contact h2 switches on the relay Y. With the contacts y 1 and y 2, the exchange transmission is switched to the internal route. The internal connection is now established as described above. Way, assuming that the inner weave is free. If, on the other hand, the internal route is occupied, when the inquiry route is switched on, a ticker symbol (Fig . 2) is transmitted.

In the rest position of contact y4 , the bistable multivibrator MV2 is blocked. If, however, the contact y 4 moves into its working position, the multivibrator MV2 is also released as long as the bistable multivibrator BM7 is in the rest position. When Bele-Clen the free inner path, since the contact 1 C is initially still in the rest position, the bistable multivibrator BM7 is reversed via the AND circuit T10i and the astable multivibrator MV2 is stopped. If, on the other hand, the inner set is already occupied, then the AND circuit T10i has ground potential and the bistable multivibrator BM7 cannot be reversed. The ticker symbol Ti is therefore active while the inquiry path is switched on. When downshifting, i. H. when the contact y4 is returned to the rest position, the multivibrator MV2 is stopped and the bistable multivibrator BM7 is possibly brought into its initial position.

The switching back of the intercom station to the exchange line is done by pressing the button again. In turn, a pulse reaches the bistable flip-flop Fl via the pulse shaper JF ( FIG. 3). The driver stage RTr is now blocked again via the AND circuit T10a, since a negative potential is present at the left input of the AND circuit T10a. This has the consequence that the relay H drops out and thus also causes the relay Y to switch off via the contact h2.

Instead of switching the inquiring office back to the occupied exchange line, the inquired office can also take over the exchange call. For this purpose, it is necessary for the inquired office to press its earth key. The blocked AND circuit T2a is bypassed by the AND circuit T8a in the event that the extension N2 is the receiving station for the exchange call. In this case, all inputs of this AND circuit T 8 a are characterized by positive potential, so that the bistable multivibrator BM2a can be reversed via the output of this AND circuit. With this reversal, the relay U2 responds, which with its contacts u21 and u22 switches the trunk line transmitter to the voice line leading to the extension N2 . At the same time, the bistable multivibrator BM1a is deleted and the relay U1 is deenergized, so that the connection of the station NI to the exchange line is canceled. The processes with regard to the relays Y and H are the same as those described above when the interrogating intercom was switched back to the exchange line. End of the exchange call At the end of the call, the relay S drops out when the subscriber loop is opened. The timer Zl is actuated via the contact s2, which, if the state at its input lasts longer than a dial pulse pause, triggers the erase pulse generator Lf. The reset pulse resets the actuated bistable switching elements (BM and (F)).

Incoming exchange connection The intercom at which the respective An exchange call should arrive is indicated by the switch NI. Through the switch W is the place to which the call is to be given, determined.

The call relay AR ( Fig. 1) is switched on via the ringing current from the exchange. The contact ar 1 (F i g. 3) ., T to the AND gates T 4 a, T 5 a and T 6 a ground potential. However, only the gate identified by the switch NI is permeable. Thus, in the assumed exemplary embodiment, the bistable multivibrator BMla is activated and the relay Ul is switched on. The contacts ull and u12 switch the intercom to the exchange transmission. With the contacts ar 2 and ar 3 ( Fig. 1) , ringing voltage is applied in time with the incoming ringing pulses and one winding of the relay S is short-circuited. When the call station closes the loop by hanging up the handset, the relay S responds and switches the speech path through with its contact sl. The other processes are the same as for the outgoing connection.

If the intercom is occupied internally for an exchange call, the output al is negative and the AND circuit T4a is blocked. The multivibrator MY transmits a warning sign AZ to the internal connection via switch N2 and contact tl.

If the present outside call is not queried within a certain time, the toe member Z1 of the flip-flopF2 knocks over and the AND gate of the position determined by the switch W, z. B. the AND circuit T 5 a, open. At the same time, the previous setting is deleted. By the further call allocation, the Anschalterelais U2 is now energized, the interconnects with its contacts u21 and u22 the Weiterrufstelle with the exchange circuit AL. The contacts nk, via which the exchange line AL can be interconnected with the subscriber station N2 , for example, are contacts of a network control relay NK, not shown, which drops out in the event of a power failure and connects the exchange line directly to the relevant subscriber station N2 so that they make outgoing exchange calls and incoming exchange calls in Can receive.

Claims (2)

Claims: 1. Circuit arrangement for partially electronic small private branch exchanges with an exchange line and an internal connection set, which are connected to the calling and / or to be called extension subscriber via the individual subscribers assigned and influenced by appropriate switching measures of these subscribers, d a - characterized in that these relay (T 1 to T n and U 1 to U n) over their associated bistable (to Nn N1) influenced by the respectively associated subscriber latches (BM11 to BMW g in Fi. 2 and BM1a to BMn a in F i g. 3) switched on and kept energized for the duration of the working state of these flip-flops until a further switching measure is carried out by the respective subscribers and that these flip-flops each have a speech that can be influenced by the other flip-flops and prevents the simultaneous occupation of the exchange line or the internal connection set by several subscribers rrgatter (Tli to Tni or T 1 a to T na) is connected upstream. 2. Circuit arrangement according to claim 1, characterized in that by the response of the feed and pulse relay (J) of the internal connection set via a timing element (Z) with a delay time exceeding the duration of a dialing pulse, a switching means (B) characterizing the occupied state of the connection set is switched on and at the end of a connection, a reset pulse is sent out for the electronic toggle and counting circuits which are in a certain switching state for the duration of the connection.