DE1015060B - Circuit arrangement for preventing unintentional call stimulation in telephone systems with crossbar switches - Google Patents

Description

It is known to prevent unintentional calling incentives in telephone systems, the subscriber line to put in a so-called catch circuit if the subscriber line is faulty, a Outgoing connection established via this line does not lead to the goal, because any downstream connection Connection device is busy, or if a switching action by an operator is on existing call or a connection being established is disconnected. In telephone systems With run selectors it is known to design the subscriber line circuit accordingly, in such a way that in the interception circuit the isolating relay of the subscriber circuit via the subscriber loop is kept energized while the connecting devices downstream of the preselection element and in many cases the preselection organ itself can be triggered. To build such a However, at least two relays are always required in the subscriber connection circuit. Circuit arrangements of telephone systems with crossbar switches now have compared to the Circuit arrangements with rotary selectors have the particular advantage that one is significantly simplified with one Subscriber circuit can get by because the adjustment rods contained in the crossbar switch and bridges can control contacts themselves. There are circuit arrangements with crossbar switches known that in the subscriber line circuit only with a single relay, which also only has to control a single contact. If you wanted to build a Make interception circuit out of the subscriber line circuit, so one would be the special Give up the advantage of this system, which essentially consists of the simplified subscriber line circuit.

For telephone systems in which the subscriber lines are connected to contacts of the selector bar of a I. Coordinate selector are connected, whose switch rails over the switch rails of a II. Coordinate selector are connected to intermediate circuits, it is already known that after triggering a Connection until the subscriber is hooked up, a safety circuit is closed over at least one contact of the switching rail of the first coordinate selector involved in the connection, the to This switching rail belonging switching magnet and the subscriber loop runs and through which the Switching solenoid is held in the working position. Such an interception circuit does not require any special effort on the subscriber line circuit, but it has the disadvantage that as a result of Holding the switching magnet of the shift rail of the circuit arrangement

to prevent inadvertent incentive calls in telephone systems

with coordinate switches

Applicant:

Telefonbau and Normalzeit GmbH,
Frankfurt / M., Mainzer Landstr. 136-142

Dipl.-Ing. Karl Wiedemann, Offenbach / M.,
has been named as the inventor

I. Coordinate selector over the subscriber line a continuation of the flying restart circuit in the event of a subsequent selection of the one held in the flying restart circuit Participant is not guaranteed. The switching magnet ^ which is excited from the marker must be very be responsive, and as a result one cannot design one's winding or windings in such a way that that it does not drop during an impulse via the subscriber line.

In order to overcome this disadvantage of the known arrangements of this type, in the present invention suggested that after the termination of a connection until the subscriber was hung up The interception circuit runs via a relay, which is activated when the first coordinate switch is switched through actuated auxiliary contacts is connected to the speech circuit and the switching magnet keeps excited. This relay, which is in each case of the switching rail of the first crossbar that is in use is assigned, can now easily be dimensioned and with additional windings be interpreted that there is an impulse on the subscriber loop during the existence a flying restart circuit does not drop out. This relay can also be used for double assignments of the To avoid coordinate selector, as it is only necessary for this to have an additional winding of this Relay energized during the implementation of each setting process in and with the relevant selector keep.

The drawing shows an exemplary embodiment of the invention on the basis of a simplified circuit arrangement a telephone system with I. and II. Coordinate selectors shown.

709 660/1 «

In the exemplary embodiment, subscriber selectors TW and connection selectors VW are provided, which are equipped with cross members Q and with shift rods S. The cross links Q of the subscriber selector TW are assigned to the individual subscribers Nst , while the Ouerglieder Q of the connection selector VW are assigned to the shift rods 5 ^{1 of} the selector TW . A free connection set Ü is reached via the shift rods 6 * of the selector VW , via which the further connection is established via further connection stages. For this purpose, the transmitter gives access to a register, not shown, which records the digits selected by the subscriber and evaluates them to provide the desired subscriber output. There is also a marker M , which is not shown in detail and which has the task of setting the associated subscriber dialer TW and a connection dialer VW so that the calling station Nst receives access to a free connection set U when an extension is called.

If the intercom station Nst lifts its receiver, the relay R assigned to this intercom station, which has only a single contact r , is activated. The contact r is the cause characters in the common marking M, by the shown because known manner is not detected, a free junctor Ü and in which this connection set associated connection selector VW made a free cross member Q (VW) to locate in. The magnet QM of this cross member is switched on from the marker via contact ts 3, which is in the idle position, and at the same time - also controlled by the marker - the cross member Q of the subscriber selector TW assigned to the calling subscriber is activated by excitation of the assigned magnet QM (TW) adjusted. When the cross member Q (VlV) of the connection selector VW is moved, the contacts labeled t (VW) are actuated, whereby the relay TS is switched on via its winding I. The contact ts 1 switches on the bar magnet SM (TW) of the subscriber selector TW , whereby the cross member of the subscriber Nst is actuated so that the contacts t (TWl-TWIl) dependent on an adjustment of this Ouer member turn off the relay ie from the subscriber connection circuit. The transverse magnets QM (TW) and QM (VW) are de-excited by the marking device M. The rod magnet SM (VW) of the connection selector VW is held by the connection set Ü , since the relay / is excited via the subscriber loop, which in turn the relay V to respond.

If the connection set is now activated without the call station in question having hung up, i.e. if the call station is thrown off, for example because it does not dial properly, disconnects the operator or, in the event of an attempt at a connection that is not entitled to the call station in question, the follow-up mechanism triggers the connection, then speaks the relay TR in connection set Ü and separates with its contact tr the holding circuit of the bar magnet SM (VW) . The rod drops and releases the cross member Q of the connection selector VW , as a result of which the isolating contacts t (VW) go into the rest position. During this switching state, the relay TS remains on its winding I, the isolating contacts t (VWl-VWH) in the rest position, the actuated rod contacts s (TWl-VWIl) of the subscriber selector TW and the subscriber loop. The contact ts 1 gives the winding III of the relay TS such an auxiliary excitation that this relay does not drop out if the intercom Nst lets its dial expire during the interception circuit. Another winding II of the relay TS _1, which is made effective via the contact ts2 , is dependent on the contact uv of a relay UV, not shown, of the marker M. This relay UV is actuated during all setting processes and prevents the cross-connecting link Q (VW) from being released as long as there is another adjustment runs.

During the interception circuit, the extension unit receives the busy signal transmitted via the windings of relay B. The interception circuit is terminated by hanging up the intercom, because in this case the relay TS drops out and the switch bar of the subscriber selector TW that is still held is triggered.

Claims (5)

Patent claims: 1. Circuit arrangement to prevent unintentional call incentives in telephone systems, in which the subscriber lines are connected to contacts of an I. coordinate switch, the switching rails of which are connected to intermediate circuits via switching rails of a II Participant's interception circuit runs through a relay (TS) , which is connected to the speech circuit by means of auxiliary contacts activated when the first crossbar switch is switched through and keeps the switching magnet energized. 2. Circuit arrangement according to claim 1, characterized in that the relay is in use taken switch rail of the I. crossbar switch is assigned. 3. Circuit arrangement according to claim 1 and 2, characterized in that the circuit of the relay depends on the contacts of the II the switching of this switch in their Rijlielage to return. 4. Circuit arrangement according to claim 1 to 3, characterized in that the relay has a additional winding an the attitude of the relay during a current impulse by the in the Interception circuit held participant receives securing auxiliary excitation. 5. Circuit arrangement according to claim 1 to 4, characterized in that a further Winding the relay is kept energized while an adjustment process is being carried out. Considered publications:
German patent specification No. 943 125. 1 sheet of drawings © 70 »« 60/146 8.57