DE1049438B - - Google Patents

Description

GERMAN

kl. 21 a ³ 67/40

INTERNAT. KL. H 04 HI

PATENT OFFICE

S 57409 VIII a / 21 a ³

REGISTRATION DATE: March 18, 1958

NOTICE THE REGISTRATION AND ISSUE OF THE

AU SLEGE S CHRI FT: January 29, 1959

The invention relates to a circuit arrangement for receiving. soundfre ^ uenten SteueT-sisüakn_ aui._ wired or wireless. Cables. The signals can be transmitted by audio-frequency signal streams themselves or by carrier currents that are modulated by raw audio-frequency signal streams.

The cost of the carrier current systems are reduced to such an extent that these systems can also be used on shorter distances, e.g. B. in local networks, can be used. In this case, however, the line relay sets assigned to the carrier current systems in the determination devices play a significant role. Given the large number of lines, it is therefore necessary to reduce the cost of these relay sets as much as possible. A promising way of doing this is to concentrate signal receivers, in which a central audio frequency signal receiver accessible to many lines (e.g. for many frequencies in the multi-frequency code method) with associated relays is temporarily connected to the line by a simple signal receiver assigned to the line. This considerably reduces the number of relays in the line relay sets. But even a simple signal receiver assigned to the line, which must be suitable for separating the signals from the speech with sufficient certainty, is expensive. A signal channel lying outside the voice band would also be too costly in a future application of carrier current systems in local area networks, because indhnduelle facilities such as e.g. B. Filters, would have to be provided.

The invention now shows a way in which the complexity of those devices which are individually assigned to the line can be reduced even further. It is assumed that all signals are within the voice frequency band. The invention proceeds from the known Verfalhren from any control character, regardless of whether it is provided in or opposite to the transport direction, to be provided with a pre-signal which the Tonsighalemplfäng'er "aüfsch üsselt 1 or turns to the line.

According to the invention, a line is only provided with those holding means, such as a resonance circuit, a timing circuit etc., permanently assigned to the evaluation of such audio frequency currents occurring on the line are suitable, which correspond to a distant signal in terms of their frequencies, but only last such a fraction of time that the occurrence of a distant signal is likely is, and that depending on this evaluation, the further test for any distant signal

Circuit arrangement for reception
of audio-frequency control signals,
each with a tone frequency
Distant signal are provided, in telecommunications, in particular telephone systems

Applicant:
Siemens & Halske Aktiengesellschaft,
Berlin and Munich,
Munich 2, Wittelsbacherplatz 2

Dr.-Ing. Friedrich Pfleiderer, Munich-Solln, has been named as the inventor

by a receiver that is shared by several lines and tuned to the distant signal, whichever is connected to the relevant line via a line fuse.

Another advantageous embodiment of the invention is that after the final evaluation of a distant signal a signal receiver shared by several distant signal receivers, which is responsible for the evaluation the actual control character is determined, for their evaluation passed on to the line is switched on. The central control character receiver then sends the evaluated signal to you Zeidhensammler assigned to the distant signal receiver, who in the office is occupied with the line in question marks or with the help of a signal transmitter the signal either to a marker of one's own office or via the following connection device as a tone signal on an outgoing line sends.

According to a further feature of the invention, the one that switches on the common distant signal receiver Vorsignalsudher released again * after the character collector has all set up for the further connection has passed on the necessary characters.

The invention can be applied with preference to carrier frequency systems, but also to pure tone dialing systems use.

809 747/123

1

The fi, g. 1 and 2 show an embodiment of the invention. The general connection setup can be seen on the basis of the block diagram shown in FIG. 1, while FIG. 2 shows circuit details of the individual connection devices insofar as they are important for understanding the invention.

In Fig. 1, L is an incoming, z. B. denotes two-wire line that is inductively sealed off with a so-called line assignment set LBS and continues two-wire or possibly single-wire to a connection field VF . The connection field can e.g. B. consist of coupling fields of crossbar selectors or cross-coil selectors. Its setting on the continuing connection path is effected in a known manner by a central marker M. In the line seizure record, the audio frequency signals coming from the forward direction of the seizure, the dialing, the triggering arrive, as are the signals coming from the reverse, such as e.g. B. busy signal, end of dialing, subscriber signaling, closing signal, etc. In addition to an occupancy relay, the line seizure record is now only assigned a "distant signal detector" VM , which evaluates the beginning of a distant signal, after about 50 ms, if it is already suspected that it is a Distant signal acts. This evaluation is transmitted to a starting device Anl common to several lines, which has a fast-switching, e.g. B. starts switching in 5 ms, line finder LS , which is not designed as a mechanical stepping mechanism, but as a relay selector, electronic selector or cross-coil selector. The line switch checks the pre-signal indicator VM of the line seizure record. This means that a common VSE pre-signal receiver, which is matched to the distant signal and equipped with a voice block, is connected to the line. As soon as the distant signal receiver evaluates a distant signal after being connected to the line, another audio frequency signal receiver TSE shared by several distant signal receivers is temporarily connected to the line, which is intended to receive and evaluate the actual control characters following the distant signals. This gives the evaluated character in direct current via one or more wires a, to a character collector ZS assigned to the distant signal receiver, which in turn marks the line in question as busy or passes the character recorded in coded form to the marker M of the own office or, if necessary, via a character transmitter ZD converts the character back into audio-frequency characters and passes them on as such via the outgoing line.

After this general description, move on to the circuit details shown in FIG.

The incoming line L is inductively sealed off in the line assignment set LBS by the transformer Ue. It should continue with a single core to the switching matrix P ^-r F. An isolating diode TD , which is able to isolate the line if necessary, is switched into the single-core line. The distant signal detector VM on the incoming line side contains a resonance circuit RK, tuned to the frequency or frequencies of the distant signal, in the form of a transformer connected between the line cores for receiving the audio frequencies. . As soon as such fire sequences occur on the line, they are transferred to the distant signal 438 via the rectifier Gr 1

meider also assigned resistor-capacitor element Rl, Cl transferred. The time constant of this timing element is dimensioned so that the capacitor C 1 after a certain time, e.g. B. 50 ms, after which it is likely that it is a preliminary signal, is charged so far that the capacitor C2 lying parallel to the capacitor C1 via the decoupling rectifier Gr 2 comes to the same voltage. The capacitor C2 is common to several pre-signal detectors and thus several lines. The charging of the capacitor C2 results in a base-emitter current of the transistor Tr 2 , which unlocks the transistor so that an emitter-collector current now flows:

1. +, Em, Ko (Tr2), An, -.

Relay A11 responds as a result of this increased current. Relay An connects a circuit for a drive relay VS of the line connector:

2. +, Unt, an, pi, VS, -.

For the sake of simplicity, the line sucber is shown as a mechanical step switch mechanism. However, it preferably consists of a fast-switching selector of a different principle. The voter now starts up and looks for the line that is not yet in use by checking the timer of the distant signal detector. As soon as he finds this, an emitter-base current of the transistor Tr 3 _{flows through the switching point I} S ^{- I of the line finder:}

3. 4-, Em, Ba (TrZ), si, Cl +.

This current unlocks the transistor. This results in an increased current through the transistor Tr3 for the test relay P :

4. +, Em, Ko (Tr 3), Ρ, -.

Relay P switches through its contacts p3, p4, p5 and the switching points s 2, s3, .? 4 of the line finder to the line. By opening the contact pl , the drive relay f ^ S * is switched off and the interrupter to the starting chain is switched on via contact / »2. The pre-signal receiver VSE, which is tuned to the frequency of the pre-signal and which is provided with speech protection, is now connected to the line L via the pass-through point i2 and the contact point p 3 blocked again because no more voltage is brought to the capacitor via line L and resonance circuit RK. Relay P drops out, which restores the central facility to its original state. But if it was a distant signal, the distant signal receiver VSE responds to this immediately and energizes the receiving relay VE. If necessary kaTin in the distant signal receiver also the. remaining length of the distant signal must be measured before relay VE responds. Relay VE energizes Relay V:

5. +, w 10, V, -.

As soon as the distant signal is over, Rdais VE and then relay V drops out. During the release time of relay V , relay D is energized:

6. +, v8, ve9> D, -.

After relay V has dropped, relay D also drops. During the release time of the relay D, the one for the evaluation of the actual control

Claims (1)

signal certain tone signal receivers TSE switched on via the line χ to the line L : 7. TSE, x, d-6, wll, C3, p3, s2, L. The receiver TSE now evaluates the control character, regardless of whether the signal was transmitted in or opposite to the traffic direction. It then transmits the evaluated character over one of the wires a, z. B. a2, and contact d7 direct current, but in coded form to the character collector ZS, which stores the character. At the same time, relay T and, if it was a return signal, relay W is also energized via the character collector. Relay T influences the isolating diode TD in the following circuit: 8. +, Ueil, TD, s 3, ρ 4, tl3, -. The line L is blocked by changing the bias voltage of this diode. The purpose of this is to prevent the audio signal receiver TSE from responding when the converted audio signals are passed on to the next line section. The character collector ZS identifies z. B. via contact p 5 and switching point s4 the line in question in the line assignment set by means of a relay assigned to this (not shown) as l> esets. In the same way, the character collector transmits the character, if necessary, to the marker M of his own office. Finally, the character collector can transmit the stored character, if necessary, to the signal transmitter ZD , which in turn converts it into audio-frequency signals and forwards it to the outgoing line L to the connection field VF via the wire ^, contacts w 12, p 4, s3 . The forward signals arriving in the meantime via the incoming side of the line L can then still influence the audio frequency signal receiver TSE via s2, p3, C 3, wll, d 6, χ. If it was a return signal, the signal transmitter ZD transmits the audio-frequency signals backwards via wire y, wl5, C3, p3, s2, Uell, +. The control characters arriving backwards are then given to the audio frequency signal receiver in the following way, since the line at the isolating diode TD is interrupted: 9. L, s3, ρ4, w 14, d6, x, TSE. bound or wireless lines, in telecommunication systems, in particular telecommunication systems, characterized in that only those switching means such as resonance circuit (RK), timing circuit (Rl, Cl) etc. are permanently assigned to a line, which are used to evaluate those on the line occurring audio frequency currents are suitable, which correspond to a distant signal in terms of their frequencies, but only last such a temporal fraction of the same that the occurrence of a distant signal is probable, and that, depending on this evaluation, the further check for the possibly existing distant signal through a number of common lines , receiver (VSE) tuned to the distant signal, which is connected to the relevant line via a line finder (LS). 2. Circuit arrangement according to claim 1, characterized in that a line- own timing element (Rl, Cl) is influenced by a line-own, tuned to the distant signal receiving resonance circuit (RK) when recording corresponding frequencies, the time constant of which determines the duration of the character to be recorded. 3. Circuit arrangement according to claim 2, characterized in that the capacitor (Cl) of the timing element is charged after the time determined by the time constant and in turn closes a starting circuit common to several lines by means of a second capacitor (C2) . 4. A circuit arrangement according to claim 1, characterized in that the line finder connecting the distant signal receiver to the line checks for the line's own timing element (charged capacitor C 1). 5. Circuit arrangement according to claim 1, characterized in that after receiving and evaluating a distant signal in the multiple lines common distant signal receiver (VSE) switching means (VE, V, D) become effective, which one of the distant signal receivers common for the evaluation of the distant signals 35 As soon as the symbol collector or sender has passed on the symbols, it becomes the central facility released again. The switching operations are not shown for the sake of clarity. It should also be mentioned that if necessary, e.g. B. if only tone-frequency number pulses are to be evaluated, the distant signal receiver VSE can be designed to receive and evaluate these characters, so that in this case a special over-central signal receiver TSE. for the control characters can be omitted. Patent claims: 1. Circuit arrangement for receiving audio-frequency control signals, which are each provided with an audio-frequency pre-signal, temporarily switch on certain audio signal receivers (TSE) to the relevant line on subsequent control characters. 6. A circuit arrangement mach claim 5, characterized in that the tone signal receiver (TSE) serving for the evaluation of the actual control characters transmits the characters evaluated by it to a character collector (ZS) assigned to the distant signal receiver, which they use to further establish the connection either directly or via a signal transmitter (ZD) passes on. 7. Circuit arrangement nadi claim 6, characterized in that the character collector converts the first evaluated character into the occupancy of the line concerned. 8. Circuit arrangement according to claim 7, characterized in that after passing on the Characters from the character collector are released again to the common recipient. 1 sheet of drawings © 809 747/123 1.59