DE677282C - Telephone system with stations located in a common closed-circuit monitored line - Google Patents

Description

Telephone system with a common quiescent current monitored line Stations The present invention relates to telephone systems in which the individual subscriber loops leading into the control center with simultaneous use the loops for reporting purposes by means of looped detectors in a common Quiescent current loop united and individual telephone calls in the control center both at undisturbed as well as with disturbed subscriber loop are possible. With a well-known Arrangement with safety circuit for the transmission of messages from a receiving point to another, in which the individual message loops are also in a common Quiescent current loop are combined, the call receiving organs provided for the individual call are located in bridge to the individual message loops and are therefore permanently in the closed circuit with switched on. This results in undesirable current branches that the Significantly impaired the safety of the plant. In particular here are very precise coordination and dimensioning of the receiving relay switched on in the closed circuit necessary.

The present invention simplifies such arrangements by it avoids current branching in the closed-circuit current loop, "thereby increasing safety of such systems is increased. It achieves this through the fact that the individual Subscriber loops individually assigned call receiving organs in the exchange for 'the telephone traffic with a part of a subscriber for the production a long-distance, voice connection caused a call stimulus to the closed-circuit current loop immediately switched on and made to respond in this. That will be beneficial Call receiving organ designed with a switchable start winding, such that if the loop is undisturbed, it is indirect through direct current and if the subscriber loop is disturbed by alternating current immediately 'to respond. The indirect excitation of the Call receiving organ takes place in such a way that the start winding a certain Has DC resistance and in the case of a call in bridge to the loop branches from see a relay that responds to current changes to all participants is placed. Only that call reception relay can respond which is parallel to a calling subscriber station lies. Due to an individual call, which is recognized by an optical signal attached to a jack the call can be queried and in a known manner via connection means, z. B.-be switched through according to the two-string principle. This will be useful maintaining the subscriber loops involved in a telephone connection the closed-circuit current loop for the other subscriber loops from the closed-circuit current loop separated and to the connection devices for the establishment of the telephone connection turned on. The connection takes place advantageously in the way; that also with the disturbed subscriber loop is able to speak.

According to the further invention, provision is made that a in the Loop next to telephone stations arranged detectors prefers its current impulse can send to headquarters. Accordingly, the invention provides switching means in Connecting circuit before which at the beginning. address a submitted message and interrupt the telephone connection in favor of a message transmission. at the current surges caused during the message delivery also becomes the common one, normally The relay triggering the telephone call in the control center is energized. To make a phone call In the event of the message, the indirect connection of the start-up winding is therefore to be prevented suppressed for the call reception relay by delaying means.

The features of the invention are best understood from a description of an embodiment.

The embodiment deals with a circuit arrangement for loop lines operated with quiescent current, which detectors and telephones contain; if necessary, alarm clocks can also be accommodated in the loops be. This telecommunication system works in a safety circuit, i. H. Messages will be not only if the line is undisturbed, but also if the line is disturbed due to a broken wire. or earth fault as well as wire entanglement received.

Likewise, the embodiment provides the possibility of a To be able to carry out telephone operation with a disturbed and undisturbed loop. The arrangement is made such that the closed-circuit monitored loop is divided into several each in the center opening loops is divided, each of the sub-loops has only one telephone next to the detectors. Naturlieh can do more Loops can be provided in which only detectors and / or alarm clocks are switched on. In the common part - the quiescent current loops there is normally one energized relay T, which responds to any weakening change in the quiescent current. It is used to record call IDs on the part of the in the sub-loop lying individual telephone parts.

Each sub-loop provided with a telephone station has two relays TA and TV. There is also a jack 1 (1 and a call sign L.

The usual changeover switches, which in the event of a wire break or in the event of an alarm are to be operated, are with D! designated.

Telephone traffic takes place with the assistance of a. in the central office and the plugging cord.

The other monitoring and control switching means are known per se and do not need to be mentioned here The central receiving station in the detectors is only the essentials shown, the familiarity of this reception center operated according to Morse code security is assumed.

A circuit example is only used for sub-loop III arriving telephone station T3 has been shown. The telephone station owns Local battery operation and has a microtelephon and a call alarm clock Inductor and two buttons. The AT key is the call key, which when pressed switches on the resistor W in the loop. The ST key is the talk key. The .4T detectors in the loop are only shown schematically been. When one of the detectors is activated, after a long power interruption Given a series of signaling currents, which are received and received in the receiving point Acting pressure devices in a manner known per se.

Both the telephone stations and the detectors as well as the individual Alarm clocks A, not shown, have a ground connection, which is also used in the event of a malfunction Loop secures telecommunications operations. Both outgoing and incoming Speech and ringing currents flowing to the telephone station run over the earth branch. The alternating call currents generated by the inductor also take the marked Way in which, by the way, the capacitor C is switched on.

The mode of operation of the telephone system is as follows: Normally flows from the quiescent current battery RB 'a current of a certain size across the various merging into the headquarters cascaded lower loops I to IV. From. This quiescent current, the relay T is kept constantly energized and holds with its contact ts the circuit of the delayed relay I is open. Through this the circuit of the further delayed relay II is maintained and with contact II4 the circuit prepared for the relay TP.

The participant, e.g. B. T3, which is turned on in sub-loop III lies, presses his call button AT and sets the for a corresponding time Resistance W in the loop. It weakens the quiescent current so much that relay T has to come to waste. With contact 1s, relay 1 is activated after a short time brought and thus the circuit of the relay TP is closed. The excitation time of the Relay TP depends on the delay time of the relay II, which as a result of its Winding parallel high capacitance capacitor is significant. The relay TP closes its contacts tpl to tp @ 3 and sets the starting windings I of the relays TA, to TA3 in bridge to the loop branches of the lower loops I to III. While these start-up windings remain short-circuited in loops I and II, the Address the start-up winding of the relay TA3 parallel to the resistor W of the call station Ts. With contact 1a34 relay TA3 creates itself via winding II depending on the Contact 1v34 the holding circuit. With contact (a32 is also dependent from contact 1v32, the lamp L3 ignited, via the common relay 1 (R. The relay I (R brings in the common control lamp 1 (L and, if necessary, also acoustic signal. The illuminated individual call lamp L3 indicates the control panel operation the presence of the call from the T3 intercom and asks you to interrogate it, d. H. Plug the latch l (13 on.

If the interrogation plug Ast is plugged into the calling jack I (13, the relays TV3 or UI winding 1 respond via the c-wire. The responding relay TV3 switches its contacts 1v31 and t%, whereby the wires of loop III together Before that, the closed-circuit current loop was kept closed with contact (v33, so that no message is triggered. Contacts 1v34 and tv39 switch off the call reception relay TA3 and the call lamp Ls.

Relay U I is created via the jack sleeve and the d-wire of the plug a holding circuit via its winding II. With its contact u 12, it lays preparatory the relay SR I to the a-wire of the cord. However, the relay cannot respond, since there is a. sealed off by the capacitor Cs, which is connected to the b-wire of the jack is.

The officer can use her query key AS Switch on and find out what the calling subscriber T3 wanted. Will this participant z. B. with the subscriber TL of the sub-loop I tele # phonic, so stuck the officer pushes the connecting plug Vst into the corresponding latch 1 (l1 relay TV is made to respond with relay U II. Relay TV, effects in the same Way, as this was described for loop III, the interconnection of the a-, b-wires, also the loop I to the pawl spring a, after the closed-circuit current loop axn contact 1v13 had been maintained.

If the officer activates her call key RS, she lays it down in detail Pole changer PW, not shown, which calls alternating current via the a-wire and earth sends. This alternating ringing current goes through the capacitor C1 and the capacitor the station, whereby the alarm clock in the subscriber station TI is activated.

After lifting the handset at the point called, the alternating speech currents via the parallel-connected wires of loops I and III and via earth as a return conductor get lost. At the end of the speech connection, the participants press briefly their inductor, which emits low-period alternating current. This alternating current is able to use the capacitor C3 or C, the relay SR I or SR II to Bringing appeal. With the contacts sr h and sr I I6 are tail lamps SLl or SL., brought to light up. They stay on because they are relay SR Place I and SR II in holding circuits via their windings II. Due to the mutual At the end, the officer at the headquarters pulls the stopper, which means that it is in rest position is effected again.

It is possible to enter by pressing a call button RT through the intermediary of a relay RR also the calling subscriber call sign from the pole changer PW.

If a detector causes signal current surges, ie intermittent interruptions of the quiescent current, the receiving means located in the control center are set. The telephone pagers, however, are not made to respond, since the delay relays 1 and II prevent the relay TA from starting.

If a detector is pulled during the call, in In a well-known way, apart from the intermittent looping refraction Earth created. The start-up windings of the relay SR that are connected to the earthed battery I and SR II of the cord receive excitation current and respond. They bring, As described above, the tail lamps as a request to separate the conversation. With The contacts sr 1s and sr IIE are also the circuits of the relays TVg and TV, immediately interrupted, and these relays put their contacts back on Rest, so that the lower loops are switched back into the closed circuit, via which the actual reporting can then take place. That way will a forced interruption of the conversation due to the discharge current that precedes each message causes in favor of the message to be preferred in each case.

If a wire break occurs in the course of the under-looping, it becomes one identified in the headquarters by means of known facilities. Because of of the D seam break sign are the switches, e.g. D, 3, to operate. Above all, it is the switching contact 13 through which the start-up winding I of the relay TA3 is switched to the capacitor C3. The other contacts of the Wire break switch insert throttles Dr3 or Dr4, which are not explained further here Purposes.

If a telephone call is made with a disturbed loop III, so has pressing the call button AT has no effect, it is rather the inductor closed actuate, through which the start-up winding of the relay TA3 to respond is brought. The following operations are essentially the same as those of undisturbed loop. If the ä or b line is broken, it can still be over the undisturbed wire and earth establish a communication link. A phone call is also possible in the event of wire breakage and grounding. In this case, however, speech communication can not be carried out a fact; recognized when the call was queried can be.

Claims (7)

PATENT CLAIMS: i. Circuit arrangement for telephone systems, in which the individual subscriber loops opening into the control center with simultaneous utilization of the loops for reporting purposes by means of looped detectors are combined in a common closed-circuit current loop and individual telephone calls in the control center are possible with both undisturbed and disturbed subscriber loops, characterized in that the individual subscriber loops individually assigned in the switching center call receiving organs (TA) for telephone traffic in the case of a call stimulus caused by a subscriber to establish a telephone connection in the closed-circuit current loop and made to respond in this: 2. A circuit arrangement as claimed in claim i, characterized in _ that the activation of the call receiving bodies takes place indirectly in the Ruheströmschleife by affecting the closed-circuit loop. 3. Circuit arrangement according to claim i and 2, characterized in that the indirect activation of the call receiving organs in the closed flow loop only takes place when the subscriber loop is undisturbed. q .. Circuit arrangement according to claims i to 3, characterized in that the call receiving device of the calling subscriber in the case of a disturbed subscriber loop, it responds immediately through alternating current. 5. Circuit arrangement according to claim i to q :, characterized in that the call receiving relay is provided with a switchable starting winding, so that this is in direct current without; with alternating current upstream capacitor is excited: 6. Circuit arrangement according to claim i to 5, in which a common relay lying in the loop responds to changes in the quiescent current, characterized in that the common Relay the start-up winding of each call reception relay in bridge to the associated one Subscriber loop places and this winding is dimensioned such that it is only parallel can address to a subscriber station in the call state. 7. Circuit arrangement according to claims i to 6 with detectors located in the subscriber loops, thereby characterized that the common; Relays in the closed circuit use the start-up winding the call reception relay switches on via delay-on-response means. B. Circuit arrangement according to claim i to 7; characterized in that switching means (Tv) are provided which switches off the call reception relay when the voice connection is established and maintaining the subscriber loops involved in a telephone connection the closed-circuit current loop for the other subscriber loops from the closed-circuit current loop disconnect and to the connection devices for the establishment of the telephone connection turn on. G. Circuit arrangement according to Claims 1 to 8, characterized characterized in that the connection of the subscriber loops to the connection devices takes place in such a way that speech is possible even when the subscriber loop is disturbed can be done. ok Circuit arrangement according to Claims i to 9, characterized in that that messages act on switching means (SR) in the telephone connection circuit, which is interrupted in favor of the message transmission.