DE1031838B - Circuit arrangement for preventing disruptive effects from discharging or charging currents of capacitors and lines in telecommunication systems, in particular telephone systems - Google Patents

Description

GERMAN

The invention relates to circuit arrangements for preventing disruptive effects from discharge or charging currents of capacitors and lines in the case of DC control signs between switching devices on the receiving relay in the assembly direction (forward sign) and against the assembly direction (Backward sign) as well as internal processes in telecommunication systems, especially telephone systems.

It is known that after the beginning and the end of a Control character, strongest in the event of a potential reversal, on the capacitors between the line wires or a line cadre and battery pole are lying, as well as a charge remains due to the Leitumgskapacity, which, as soon as you in or after the sending of control characters or with any switching process in Connected facilities a way for discharging or charging is offered, compensates for this. With one on the sending side on the relay lying on the line and not involved in the signaling, the fault current value is exceeded and therefore the relay armature will be tightened incorrectly. It can also be found on the opposite side of the toe reception Telai'S the armature drop off with a delay and, moreover, in the event of rapidly successive power surges (short Impulses with time-limited pauses), as they come from the number switch of a telephone set, the relay response time for the second and -: the following characters can be greatly reduced. As a result can also be used against the direction of connection establishment Signs arise or switching operations are initiated prematurely. In the construction direction can If the character distortion is too great, shorten the pause between two pulses so that the pulses converge. In any case, the proper establishment or handling of a telecommunication connection, especially telephone connection, disturbed.

With regard to damping and symmetry requirements, the capacity of the affected Do not reduce the size of the condensate arrows. To prevent the disruptive effects of capacitors and Line transfers to the relays on the line are already various switching measures known.

So when signaling in the construction direction usually the wires on the sending and receiving side are separated. Contacts are used for this of the send and receive relays as well as delay relays (control relays), isolating contacts actuated by them The main purpose of the receiving relay is a line distortion caused by capacitors to avoid. However, they are often ineffective with the first impulse. Besides, they can neither the line capacity still on the receiving side

Circuit arrangement for prevention

disruptive effects from discharging or charging currents from capacitors

and lines in telecommunications,
in particular telephone systems

Applicant:
Siemens & Halske Aktiengesellschaft,

Berlin and Munich,
Munich 2, Wittelsbacherplatz 2

Oskar Leykam, Munich,
has been named as the inventor

disconnect all capacitors. That on the sending side Receiving relays intended for giving in the opposite direction therefore usually do not receive a sufficient one Protection against the electricity currents, in particular when a symbol voltage is applied at the same time on the transmitting side, primarily via a second line wire coupled by capacitors, z. B. a tax code, remote code and the like when removing the character tr omes on the second line wire (control wire) or at the Söhluß of the signaling when the line is resumed even to an increased discharge current flow over the Wieklung of the endangered receiving relay. The protection can also differ from time to time Reduce the work of the delay relays on the connected Sdialt members. Very often the receiving relay can be used for characters In the backward direction, do not cut off the forward signs for the entire duration of the passage to secure with simultaneous signaling. After all, one has always strived for, and recently one has in the case of line transmissions, it is also realized to completely avoid disconnection contacts in the Sprec'hadern. In order to be partially ineffective, they sometimes require that the armature of the receiving relay favors the second pulse signal anyway by existing real magnetism, faster than with

809 530/122

first character- attracts / TJaduiehu begins passing of the. first character later and the following impulses earlier, the first pause is therefore for the im Connection establishment. subsequent _ receiving switch. footprint also shortened. Furthermore, contacts in dien, Spredhadern through their fluctuating transition resistance the speech understanding and In addition, the stability in four-wire circuits when disconnected disturb.

- see two rapidly successive impulse signals, while an extension would usually be necessary. In addition, separation contacts are imperfect because of their Effect and because of transmission-5 technical disadvantages, especially in relay transmissions have to be omitted. Finally, there are sometimes additional disadvantages, including time dependency of the operation of the relays in other switching elements, differently large distortion of the

Other known measures against malfunctions io first to the characters below and therefore to by discharge currents, ■ which are based on an attenuation of the rapid character string, z. B. with dialing characters, especially Response effect based, 'bring with short and disadvantageous consequences, sometimes also worsening characters following one another in rapid succession, such as B. the character penetration or increased risk the impulses of others connected to the line from the number switches are too great a character distortion. In limited to 15 relays.

In the following cases, the following can be used on the transmission side when removing

of a control character the receiving relay by briefly improving the current impulse, but only behind timely bridging against capacitor currents and the signal receiving relay, which is then sensitive to condensation be made. But this still has almost the followers and line capacities part that other relays located in the discharge circuit, 20 can have an undiminished disruptive effect. At the Stromz. B. Pulse relays for forward pulling, through a series of strong bursts they do not easily avoid pulling Electricity will be even more endangered. In addition, two impulses converge if one of the others is absent With this measure as well as with the Auftrennem contact the first impulse by opening contacts any protection occurs after the end of the sign-late and therefore the pause to the next would give z. B. when switching through the speech wires to 25 impulse is greatly shortened.

an occupied switching element. The known protective measures for changing

Current surge control circuits are also used. Current relays and polarized telegraph relays are isolated Kind became known. These are locked lines protect the receiving relay for but-only- and only, from the signal receiving relay forward signal only when signaling contrary to the distorted recorded 'Wahlstrompulses in a useful 30 construction direction (backward sign) and can be convertible current impulse ratio implemented and further - in the Zeic'benstrotnkkreis for direct current over given. Do not use a protection of the lines on the transmitting side. Satisfactory protection of the Management against discharge and charging currents endangered by the sign The interception relay is not intended to be used with these circuits still reachable. Even from the signal reception 35 second drop-out delay at the reception relay, Relays will mostly work with sufficiently long breaks, especially in the case of longer breaks that are to be provided in the future assumed between two impulses. To the non-contact. Lines, downsize and the andieser limited rush talk time improvement on a rapidly following second and after the receiving relay there are always several relays, if necessary enlarge further control characters, variable and fixed resistors, capacitors 40 to especially include the first pause time between two and rectifier necessary. . ■ It is not necessary to save characters in a usable length

Furthermore, two arrangements for the protection of are known. Furthermore, arrangement receiving relays are not satisfactory when sending backward characters known to / in the character pause and at the end known. In both. However, if there is a sign in the opposite direction, it is a wrongly locked one Lines around a signaling against 45 pulling the armature from the receiving relay to unterbkider Construction direction and. thereby to the protection of the after the receiving winding through the sending / receiving relay against line discharges. Im contacting the backward sign back to the line In the first case, an auxiliary relay must be connected to the AC relay.

relays are assigned, and in the second case, the invention aims at DC control

a polarized telegraph relay a reverse winding. 50 signaling in forwards and backwards direction and at In addition to these protective attitudes, there are also those for - ■ internal processes that are linked to one another the forward signal receiving relay, restricts switching devices for those on the line on the sending of reverse signals, known the relays, the special current and time conditions also require an auxiliary relay, but subject to, in the danger time a sufficient Control of the receiving relay capacitors and protection against disruptive capacitors and line-line transfers do not render ineffective. To offer transshipment. In addition, the line influence

■ Reduced when signaling to protect the reception to the relay anchor drop-out time, with quickly Relays on lines against disruptive capacitors- consecutive characters, e.g. B. from the number and line currents in common arrangements are switch outgoing dialing control characters, one yet limited to the connection establishment or counter-60 sufficient pause time even with long cable lines direction, on dde equalization of recorded current and contact-free line cores in the switching elements surges (surge control circuits, impulse correction achieved and the strength of interference currents reduced tion, impulse repetition) or on certain processes. The invention avoids the expense of gears (pulling backwards, reverse cable discharges) and auxiliary relays and the disadvantages of the previously used ReI aisbau types. You also need the 65 partial solutions borrowed here.

cases to be taken into consideration without exception auxiliary This is achieved according to the invention in that in

relay. The forward signs caused by the discharge and charging processes are also satisfactory seen relay contacts for separating the Lei- danger time caused by charged capacities for line wires in the 'signaling do not cause the line and the signaling rather, sometimes a shortening of the pause between 70 uninvolved relays at the end of the signaling in the

Opposite direction when the relay is switched on again, a rectifier and its effect depends on the contacts of the device that releases the interference current Relay parallel to the winding of the relay to be protected a discharged capacitor or parallel to one a charged capacitor is connected to the line of the uncharged capacitor.

The advantages of the arrangement in particular are that the inventive concept is more expedient Way either for forward and backward signals on the relay winding to be protected, if one Protection is not necessary in the case of backward signals, at the sender contact or if the time of danger is on endangered relay cannot be mastered, can be realized on the uncharged capacitor that is added leaves. In addition, the desired effects complement each other when the switching arrangement is applied according to the invention, for example, at the same time on the transmitting contact and the receiving relay. Further advantages are that discharge currents at the end of sent in both directions Sign only partially about the winding of the controlled or by sign of the opposite direction endangered relay can flow, so that the relay araker drops in a shorter time or not incorrectly is attracted. If two control characters intended for the relay are in rapid succession, the second and. any subsequent control characters delay the tightening of the relay armature additionally. For the the signaling of uninvolved receiving relays acts the protection against charging currents also delaying, e.g. B. if the line only after the end of the dialer setting is switched through. The dependency of the armature, which drops differently over time, on control relays is not applicable, and the line capacitance is also ineffective. In the speech cores, there can be separating contacts without any adverse repercussions on the line relays easily avoid, whereby Transmission improvements are added. Finally, in the case of control characters, if appropriate, by reducing the stream of characters at the end of the anchor suit a further shortening of the Anchor drop time can be reached. Through sensible arrangement the components can once the current limiting resistor at the same time to control the Time constant of the current flow to be absorbed or delivered by the capacitor of the protective arrangement on the other hand, some of the protective circuits already exist in the facility Components are also used.

From the signal reception relay lying on the lines a distortion-free transmission of the incoming control characters. The relays should generally be without additional pick-up and drop-out delays work. Above all, the response time of the relay at the first control character, which at longer lines become larger anyway, should not be delayed any further. The anchor drop time should not be either with longer cable lines © ine exceed a certain duration. In contrast, the quality of the transmission of characters suffers not if the relay response time is increased so much from the second character onwards that the The length of the continuing control characters is not less than the length of the first character. With that, the The pause time between two control characters can advantageously be increased. With regard to something like that Character relay is the following control circuits, as they are usually present in relay transmissions, except for the first character, an increase in response time is desirable. To secure a sufficient If there is a long pause, an accelerated anchor drop can be useful.

If a line relay temporarily from disconnected from the line, discharge currents may affect the receiving relay that is reapplied to the line not affect effectively. The relay should also be insensitive to charging currents that occur when it is switched on of capacities are added. Its response time should therefore be as possible at such times be large, the prescribed fault current value must not be exceeded.

These requirements are met by a capacitor, a rectifier, a contact of the Character reception relay and, if necessary, a contact of the transmission relay for the opposite direction and one each Discharge and charge resistance fulfilled. With the send contact or with an empty connected capacitor a charging resistor is not absolutely necessary. Often the components mentioned are partly can be used by other circuits.

The subject matter of the invention is explained in more detail below with reference to the exemplary embodiments shown schematically in Figures 1 to 5. Mainly simplified circuit excerpts of outgoing and incoming relay transmissions Ue-g and Ue-k in telephone connections were used, insofar as they are necessary for understanding the invention. The two relay transmissions can be connected to one another directly via selectors or via a longer galvanically guided connection line VL. The examples for the circuit arrangement according to the invention are each drawn out in greater detail.

According to Figure 1, this circuit arrangement has the same beneficial effect for receiving relay A when control characters are received by i2 and χ2 and after reverse characters have been applied by e2 / i3. Control characters can be used in the direction from transmission Ue-k to transmission Ue-g through % 2 via line wire α (dialing character) and. at the same time through x2 over the line wire fr (a remote numbering offer limited to the first character duration), in the opposite direction from the transmission Ue-g to the transmission Ue-k through e2 and. e 3 a backward character of any length can be transmitted over the two lines.

When dialing signals, i2 sends short earth pulses to the ^ relay. Only with the first impulse does i3 close the circuit for relay X, whereupon relay R responds via the now closed contact χ 1. The contact χ 2 offers on the δ-line forward remote identification voltage for a dialing end earth that is approximately present at the other end of the line, but takes it here (when connected to Ue-g) due to the floating fr-line shortly before the start of the second earth pulse in the α -Ader through t'2 again, in order to allow a character to reach relay S in the opposite direction, if necessary, and furthermore, in order not to falsely excite the winding of relay F as a result of capacitor and line surges. If i2 is now open and covers x2 , the capacities C 2, C 3, C 4 and C _L cause a charging surge across the rest side of the ^ contact, which can be very strong as long as r is still closed and the winding of relay 5 has bridged. The r-contact thus protects the winding of the relay S from the charging surge and is opened later by the fall time of the relay R after moving the ^ contacts, but before the start of the

second impulse sign. Now, in the transmission Ue-g for the receiving relay A, the strongly drawn arrangement acts as follows:

Before the arrival of the first pulse signal , the capacitor Cl had assumed full charge via the charging resistor WI , which the rectifier Gr ensures. When the control character arrives, the state of charge at capacitor Cl remains unchanged and thus the pick-up time of the ^ relay is unaffected by the additional switching arrangement until the contact a I has flipped over. The capacitor Cl now loses its charge via the discharge resistor Wl. After the ^ ί armature has dropped and the a 1 contact has been moved back, a charging current leads to the cross capacitors C 2, C3, C 4 and the line VL with the line capacitance C _L , which after moving the Jtr2 contact into the transmission Ue-k via d in the rest position and r still closed by the earth applied to the ö wire, in the transmission Ue-g initially to charge the capacitor C1 and thus only partially flows through the winding of the relay A. The current intensity in the relay can be kept slightly below the fault current value by appropriately dimensioning capacitor C1. A briefly following symbol would find capacitor C1 only partially with full charge, so that the relay current increases somewhat more slowly and the armature tightening is delayed to ensure a usable pause time.

In the event of a backward signal sent by the contacts e 2 and e 3 in the transmission Ue-g , with e 2 separating the ^ -winding, the capacitor C1 also loses its charge via the closed contact e 1. When the ^ -winding switches back to the line at the end of the character e 2, charge-reversal currents flow via capacitors C2, C 3, C4 and C _L, as with the forward sign, for the most part via Cl and only a small harmless part via the ^ -winding, see above that for these the fault current value can easily be maintained or at least the response time can be extended sufficiently.

According to Figure 2, the ^ relay would be protected without a bridging contact r in the same processes as in Figure 1 during the signaling from the transmission Ue-k to the transmission Ue-g when the contact χ 2 is moved back . Due to the omission of the bridging contact r (see Fig. 1), the character penetration is improved and the charging surge, which endangers the Α relay, is weaker. This circuit arrangement is drawn in the sense of the circuit for the A-Kt lais of the transmission Ue-g according to Figure 1 for the .S relay of the transmission Ue-k . It protects the S winding in the same way as described in Figure 1 for A when x2 travels during the first break or later. In many cases it will also be sufficient to simply connect capacitor C1 in series with rectifier Gr parallel to the endangered S winding (on the fr wire) and to bridge Cl via resistor Wl with only a χ 1 normally open contact.

Figure 3 shows a circuit variant modified from Figure 1 for multiple use of the circuit arrangement according to the invention. The first series of characters is sent to relay A1. After switching the receiving circuit through the M-contact, relay A 2 is controlled by further incoming characters. Instead of changeover contacts al and α2 of the relays Al and A2 to be protected, make contacts al and a 2 were provided. Thus, after the armature is almost finished, the relay current is weakened by the branching of the incoming character stream via Wl , so that the armature drops more rapidly at the end of the character. The break time is extended.

According to Figure 4, the circuit arrangement reduces the influence of the capacitors C 2, C 3 and C 4 and especially that of the line capacitance C _L on the fall time of the ^ armature in the transmission Ue-g during forward signaling through contact * '2.

In the idle state, capacitor C1 is charged via W2 . This is expedient here to 6 "taken Rückwärtszeidhen not to delay in a relay on the response time of the armature by .S-charging of the capacitor Cl. When working of / -Ankers t'2 control characters sends yi to the relay. At the same time i bridged 1 the capacitor C 1, so that this at each replacement of the contact il completely discharged to the α line comes. Now taking the capacitor C1 a part of the capacitor and line currents through the capacitors C2, C3, C4 and C _l. this gives the ^ (- relay also only part of the interference currents, and its armature drops off more quickly.

The protection arrangement fulfills its purpose just as well if it is moved to the center of the transformer Ü for reasons of symmetry.

In Figure 5, a discharged capacitor C 7 switched to the line at any time by contact k 2 is to be rendered ineffective by the protective capacitor C 6 for the endangered S-winding. It is assumed that when the contact k2 closes, it clears the path for interfering currents via the uncharged capacitor C 7, via the & -wire of the connecting line VL, contacts 2, relay S and contact d . When the JT relay has dropped out, capacitor C 6 is charged via Wl. The contacts k 1 and k 2 folded, capacitor C is from 6 its charge to capacitor Cl, so that can only flow a partial flow through the shunt connected .S-winding. The charging resistor Wl was arranged, for example, in such a way that it can be used to determine the duration of the discharge of the capacitor C 6.

The arrangement of Cl or C 6, Wl, W2, Gr and the contacts depends on the given circuits. By determining the size of capacitor C1 or C6, the strength of the interference current and the necessary protection time for W1 or W2 can be taken into account.

Claims (9)

Patent claims: 1. Circuit arrangement to prevent disruptive effects from discharging or charging currents of capacitors and lines in the case of DC control characters between switching devices on the receiving relay in the Aufbauridhtung (forward characters) and against the Aufbauridhtung (backward characters) as well as internal processes in telecommunications systems, especially telephone systems, characterized in that in the dangerous time caused by discharging and charging processes, the dangerous time due to charged capacities (C 2, C3, CA. and C £) for the relay connected to the line and not involved in the signaling (A or S) at the end of the signaling in the opposite direction when the relay is switched on again (A or S) , a rectifier and its effect depending on the contacts of the relay releasing the interference current (E, S, X, J and K) parallel to the winding of the relay to be protected (A or S) a discharged capacitor (C 1) or a charged capacitor (C 6) is connected in parallel to an uncharged capacitor (C 7) added to the line '. 2. Circuit arrangement according to claim 1, characterized in that if there is a risk of rapidly successive pulses converging due to discharge currents, the capacitor (C 1) via a resistor (Wl) and a contact (a1 and optionally α 2) of the receiving relay controlled by current pulses ( A or, if applicable, Al and A2) takes effect and in the event of a second and subsequent control characters that follow quickly, the response time of the receiving relay (A or, if applicable, Al and Αϊ) is delayed (Fig. 1 and 3). 3. Circuit arrangement according to claim 1 and 2, characterized in that the capacitor (C 1) is discharged via a contact (e 1) of the transmitter relay (E) of the control characters for the opposite direction and the current limiting resistor (Wl) and thereby after the anchor drop The interference current flowing back from the transmitter relay (E) , limited in time by the size of the resistor (W2) , can only partially flow through the winding of the relay requiring protection (A or possibly Al and A2) (Fig. 1 and 3). 4. A circuit arrangement according to claim 1 and following, characterized in that the contact (al or a 2) of the controlled reception relays (A, Al or A2) sets the current limit resistor in parallel with the relay winding (A, Al or A2) and NADH almost After anchor suit the Excitation current and thus the armature drop-out time is reduced (Figure 3, correspondingly also Figure 1). 5. Circuit arrangement according to claim 1 and following, characterized in that the circuit arrangement is used at the same time for several relays in need of protection (Al and A2) and is switched accordingly by contacts (Figure 3). 6. Circuit arrangement according to claim 1 and following, characterized in that the capacitor (Cl) via a contact (xl) dth control relay (X) for a time-limited number of license plates that ends in a pause between the characters sent by the relay (/) puts the discharged capacitor (C 1) parallel to the winding of the endangered relay (S) and thus does not allow the interference current to pass fully to the winding (S) (Fig. 2). 7. Circuit arrangement according to claim 1 and following, characterized in that the contact (ti) of the transmitter relay (/) at the end of the control character by the fall of the relay armature (7) the discharged capacitor (Cl) parallel to the via a contact (x2) one other control relays (X) charged capacitors (C2, CZ, C4 and Ci) in parallel and the discharge currents are mainly absorbed by the protective capacitor (Cl) (Fig. 4). 8. Circuit arrangement according to claim 1 and following, characterized in that when switching on an uncharged capacitance (C 7) through a contact (k 2) of the relay causing the interference current (K) to the line with the relay at risk of the charging current via a contact ( k 1) of the same relay (K) comes from the fully charged capacitor (C 6) (Fig. 5). 9. Circuit arrangement according to claim 1 and following, characterized in that a rectifier (Gr) between the line and protective capacitor (Cl) and a charging resistor between the rectifier (Gr) and capacitor (Cl) have a disruptive effect of the capacitor (Cl) on the line or the first response of the receiving relay. Documents considered: German Patent No. 727 637; Austrian Patent No. 171 124; French patent specification No. 970 488. 1 sheet of drawings 809 '530/122 6.