DE680314C - Circuit arrangement for telephone systems - Google Patents

Description

Circuit arrangement for telephone systems The invention relates on a circuit arrangement for telephone systems with one of two metallic Cores exist between two end points and over several branch points extending line, the optional traffic of the branch points with each other enables.

While with general telephone systems there is the possibility of in the event of a line failure, e.g. B. Disturbance of a line of a connection path between two switching devices, the traffic over another undisturbed line To handle the same connection path occurs with company management, i.e. plants with only one two-wire common line for several optionally callable subscriber stations, the difficulty of disrupting wires of this one common line, z. B. in the event of a wire break or earth fault of a wire, still carry out an emergency operation.

For such systems, facilities are already known which enable emergency operation in the event of a fault. However, these arrangements are very much inconvenient, since the participants first use the normal facilities with each call need to operate only when they discover that there is a fault in the line is available to put the emergency facilities into operation. Doing this can be unnecessary a lot of time goes by, what especially in vital operations, what such arrangements in particular are provided to be of the utmost importance. can.

For remote control systems it has also been proposed to break switch on a signal on one wire of the remote control line and then manually to switch on a reserve wire, so that the remote control operation via this wire and the undisturbed core of the control line can be maintained.

The object of the invention is to provide a safe; fast and flawless To enable emergency operation on company lines in telephone systems without Provide special reserve wires or have to switch over by hand. This is achieved in that when faults occur on line cores automatically Switching means in the central office used to control the traffic on the line become effective, which switch on a jamming control transmitter, through the at the branch points Disturbance signs are switched on, which are to be used by in the individual Branch points permanently to the Company management connected and the establishment of connections via the undisturbed core of the common line and call on earth enabling facilities. -On the drawing is a Embodiment of the invention shown, on which the invention, however is not restricted. There are only those necessary to understand the invention Details shown.

As an exemplary embodiment, a telephone system is chosen in which several subscriber stations on a connecting line VL originating from a central station ZSt TSt lie. A terminal ESt is provided at the end of the connecting line.

In the central station, the system is in the idle state on the connection line a direct current source is connected, from which a quiescent current via the connecting line and the two relays Br and X connected in parallel flow in the central station. The relay Br is excited by the quiescent current and keeps its armature attracted (Contacts i br closed,: 2 br open), while relay X only when amplified Electricity responds. Depending on these two relays Br and X, there will be no-nnalem operation when lifting the handset at a subscriber station, the connection line to a common control device StE switched through, in which the from the calling Subscriber station outgoing direct current surges are accumulated to be called alternating current surges to be sent out again to adjust the dialing mechanisms at the subscriber stations or to enable connections to other switching devices while in the event of a fault in line cores, switching means become effective, which control the connecting line switch through to the interference control transmitter HE.

The subscriber stations TS't are for normal operation with one on known and therefore only schematically shown telephone and dialing device TA equipped, while for emergency operation, simultaneously continuously on the connection line switched, an inductor station Ina is provided. Parallel to the inductor station a time switch device ZR is provided, which the on. and deactivation the fault lamp StL causes, in the terminal is in addition to these facilities still a choke Ar provided, which a bridge between the two wires of the Establishes connecting line.

In the event of a fault in the line, the time switching devices ZR are excited at the subscriber stations by a longer current surge emanating from the interference control transmitter HE , whereby the fault lamp StL requesting the use of the emergency facilities is switched on at the subscriber stations.

The switching operations in normal operation and in emergency operation are as follows: i. Normal operation When the system is idle, a quiescent current flows through the connection line: earth, the relays Br (winding I) and X, contact 3y, connection line VL, contact .Ia in the end point, throttle Dr, contact 5e , back via the Connection line, contact 6y, -. When the receiver is picked up at a subscriber station, a short circuit is produced between the two wires of the connecting line, so that the relay X also responds as a result of the current amplification in the central station. By closing the contact 7 x the relay Y is energized via: -, 7x, i br; I '; X (winding 1I), 8t, earth. Relay 1 ' responds and, by moving its contacts 3y and 6y, causes the connection line to be connected to the common control device SM, from which an alternating current surge is emitted in a known manner to block the dialing units in the subscriber stations. This reverse current surge also excites relay A in the terminal via: -, relay A (winding I), 9a, io b, r i r, earth. The relay A holds on to its second winding and the contact 1 2 b, while the pulse transmission relay R has already dropped out again, so that the relay B in the terminal does not respond. The calling subscriber now selects the desired connection by pressing his number disk, whereby a memory is set in the control device which, after the selection has ended, sends out current pulses to set the dialing mechanisms. The relays fr, X and Y remain energized in the central station for the duration of the connection. After the end of the conversation, the common control station sends a special trigger current surge over the line in a known manner, not shown, by means of which all dialing mechanisms are brought into the zero position. In the end point, apart from the pulse, transfer relay R, the relay B is energized via: -, B, 13a, 14y, earth, whereby the relay B creates a holding circuit independently of A via its contact 1.4b. By opening the contact 12 b, the relay A is switched off and the contact 13 a is opened. Furthermore, the contact 4 a is closed, so that the throttle De bridging the connecting lines is switched on again and quiescent current can flow again via the connecting line.

After the end of the conversation, the contact $ t of a relay T of the common control device is opened depending on the common control device in a manner not shown, so that the holding circuit for the relays Br, X and Y is now interrupted. The relays k and Y drop out, while the relay Br through the. the winding BrI now remains energized again flowing quiescent current. The system has returned to its idle state. 2. Emergency operation If there is a fault in the connection line due to a wire break or a ground fault in the line cores, the quiescent current is interrupted. In the central station, the relay Br drops out, whereby the relay N and, in parallel, the control lamp KI and other alarm devices, alarm clocks, etc., not shown, are switched on via the contact 2 br. An interference control transmitter HE is simultaneously connected to both wires of the connecting line via contacts 16n and 174. When switched on, a particularly long alternating current surge is automatically emitted via both wires of the connection line and earth in a manner not shown, which means that the simultaneously switched on Zeitgchalteinrichtungen ZR come to respond in the subscriber stations. First of all, the processes in a subscriber station TSt are considered. By closing contact i8zr, relay D is energized via: -, D, ige, 2o f, i, # zr, earth. Relay D is kept in the following circuit via its own contact 2i d : -, Relay D, 2i d, relay E, 22f, earth, which also causes relay E to respond and its contact 23e to close. As a result, the fault lamp StL, which calls for the use of the emergency equipment, lights up in all subscriber stations and remains on until the time switch devices ZR are again energized after the fault has been eliminated. As shown, the fault lamp StL can be fed from the high-voltage network; however, local batteries or the like can also be provided. The same processes also take place in the terminal, where relay D ' is activated via contact 24 - r' via: -, D ', 25 e', 26f ', 241-r', Eide and over - -, D ', 27d', relay E ', 28f', earth holds. As a result, (las relay E 'is energized and causes the fault lamp StL' to respond via its contact 29e '. All subscribers on the connection line are now informed of the presence of a line fault fault lamp that he has to use not provided for the normal operation of the telephone and selection means TA, but the emergency operation enabling Induktorapparat in. by Induktorkurbeln the calling subscriber can in a known manner by certain Morse o ,. like. the central office or other Call the subscriber stations of the connection line. In the meantime, the control lamp KI and possibly also other alarm signals have been switched on in the central office as a result of the relay Br dropping out, which draws attention to the fact that the connection line is no longer operating automatically, but has started emergency operation is. In the case of incoming calls to the central office, a placement officer therefore makes the desired connections to other switching facilities or company management by hand.

Once the fault has been eliminated, the relay comes to the central station. Br to respond again, whereby the control lamp KL and the relay N are switched off again. Before the contacts i6yu and 17Y6 open, however, the interference control transmitter HE again sends a particularly long alternating current surge over the connecting line in a manner not shown, which in turn causes the relays ZR, ZR 'to respond at the subscriber stations and the terminal. As a result, the relay F is energized in each subscriber station via: -, F, i9 e, 2o f, i 8 zr, earth, which is held by its contact 20f . By opening the contact 22f , the relay E is switched off, whereby the malfunction lamp goes out. In the same way, the malfunction lamp is switched off at the terminal.

After the relays ZR, ZR 'drop out, the relays F, F also drop out, so that the devices at the subscriber stations and at the terminal station return to the rest position.

Claims (1)

PATENT CLAIMS: i. Circuit arrangement for telephone systems with a line consisting of two metallic wires between two terminals and over several branch points, which enables the optional traffic of the branch points with one another, characterized in that when faults occur on line wires automatically in. The to control the traffic on the Central office switching means (Br, N) serving the line become effective, which switch on a Störsteuersen.der (He) , through which fault signals (StL) are switched on at the branch points, which are permanently connected to the company management for use in the individual branch points and the structure request of connections via the undisturbed wire of the common line and earth enabling auxiliary equipment (In). z. Circuit arrangement according to Claim r, characterized in that the auxiliary devices (In) which enable traffic via a line wire and earth are located in a bridge between the two line wires and earth. 3. Circuit arrangement according to claim r, characterized in that the control of the switching means (ZR) for the fault operation at the branch points is carried out from the central point by an alternating current of a certain duration. q .. Circuit arrangement according to claim r for systems with quiescent current operation, characterized in that. that the switching means (Br) of the central station, which become effective in the event of a fault, initiate a switching process which enables the fault signals (StL) to become effective at the branch points when the quiescent current on the line is interrupted. 5. Circuit arrangement according to claim 4, characterized in that the switching means (Br, X, Y) of the central station when a branch point is called as a result of current amplification a switching device (StE) serving to set up a connection and, in the event of a fault in a line wire as a result of interruption of the quiescent current, a disturbance control, to turn on (He). 6. Circuit arrangement according to claim r, characterized in that auxiliary switching means (D, E, F) are provided at the end of the common line, which when the disruption of a wire characterizing switching process takes effect, which enables the quiescent current over the line when the line is undisturbed Switch off the bridge (Dr). 7. Circuit arrangement according to claim t, characterized in that the auxiliary device at the branch points are equipped with call devices (In) allowing direct mutual calls from the branch points.