DE2145702B2 - Circuit arrangement for converting telegraph characters between a single power line and a double power line in teleprinter systems - Google Patents

Description

specialist current sign the transmission of incoming relays (U) is connected and its emitter prevents double current signs, in particular connected to one pole of an operating voltage source.

special in telex exchanges, it is concluded that the normally closed contact of the third

those with two-wire single-current operated switching contacts (U 3) on the double-current side

Subscriber stations connected to the switching center via four-wire double current input (s) of the logic circuit (LOG) 15 (FIG. 4).

8. Circuit arrangement according to claim 7, damerstellen without triggering the built-up Ver characterized in that two connections interruptible by counter-writing are provided as timing elements, the different Verist, characterized in that delay times cause that the relay (U) in the incoming four-wire branch (ED) has a fourth switching contact (u4), which in ncte logic circuit (LOG) at the same time one position of one of the two timing elements with the occurrence of character current state in the departing first delay time (60 ms) and in the other position of the four-wire branch (SD) and isolating current state, the other of the two timing elements in the incoming four-wire branch (Elf) which switches the Linfach current symbols arriving with a second delay (600 ms) to double-25 (Fig. 4) . current sign converting device (71) in the
Separating layer holds (by means of Eq.).

2. Circuit arrangement according to claim 1, characterized in that the logic circuit The invention relates to a circuit arrangement {LOG) a single-current-side input and output 30 for converting telegraph characters between a gang (<) and a double-ended single-wire-operated single power line and gang (d) and output («·) and has a trigger of a four-wire operated double current line gerstufe (7 / ·), the input of which is connected to the Ab- in teleprinting systems, in which the incoming double handle of a voltage divider (R3 / R4) and to the pelstromzeichen The transmission of incoming single-current-side input and output (r) is 35 single-current characters and incoming single-circuit characters and their output to the double-current character prevents the transmission of incoming current-side output (d) of the logic circuit double-current characters. This circuit (LOG) is connected, and that the double arrangement is particularly applicable in remote current-side input (e) ' and output (d) of the write switching systems, in which with two-wire logic circuit (LOG) via a gate (Gl) at 40 Single current operated subscriber places via four the base of the transistor stage (71) is connected wire double current lines to the exchange, whose emitter-collector path is connected in series and the news broadcast the voltage divider (A3 / A4) to the poles of a better subscriber station without triggering the built-up drive voltage source (Ub) , the connections are interrupted by counter-writing (FIG. 2). 45 bar.

3. Circuit arrangement according to claim 2, since Fig. 1 shows a known arrangement / to Umdurch characterized in that as a gate (Gl) a set of Telegrafiersignaleri between a / wei-NAND gate is provided (Fig. 2). wired single power line and

4. A circuit arrangement according to claim 2, characterized in that a four-wire-operated double-current Lidurch that the arriving for the 50 device. This known arrangement consists of the double current line (ED) subscriber station 7h provided for the signals and the converter circuit US. on the one hand directly to the input of a second subscriber station Tn is connected via the single current catters (G4) and on the other hand to the input line 7 / with the converter circuit US , a timer (L) is connected. that the output The lines a 1. b 1 and al.bl belong to the double gang of the second gate (G 4) on the double current line, via which the converter circuit ί'5 current-side input (s) of the logic circuit to a switching center (not shown) is connected (LOG) and that the output is closed. Of the subscriber station Tn are ledigder ZeitMuU - (/ <) connected to a relay (U) is Hch the transmitting contact Sk and reception magnet, the polarity reversal of the single power line EM of the teleprinter Fs and the distance (7f) causes (Fig. 2) . 60 switching device Fg shown. The converter circuit US

5. Circuit arrangement according to claim 4, da- contains the telegraph transmitter relay / i, whose winding is characterized in that the second gate ment I in the line circuit and its winding II (G4) an exclusive-OR gate is provided in the replica circuit, the replica resistor (Fig . 2). Rn contains, is arranged. By means of the send con-

6. Circuit arrangement according to claim 4, that 65 clocks α the double current to be sent out are characterized by the fact that the single voice side signals over the line «2, bl to the switching input (c) of the logic circuit and a pole of the point delivered through which they one Operating voltage source, not shown, can be supplied via a first and further subscriber station.

The outgoing al via the line, bl of the switching voltage of the type mentioned an incoming in ankommcnstelle double-stream signals pass the four-wire branch arranged logic circuit vorzum telegraph receiving relay ß, which seen this double, the b-current condition with simultaneous occurrence of characters current signals by means of the received contact in the Four-wire branch and via the Einfachstromleituag Tl as a single-current 5 isolating current state in the incoming four-wire branch characters to the subscriber station Tn . In addition to the incoming single current characters in the Dopdem, the converter circuit US also contains the device converting the reverse current characters in the switching contacts / 1 and / 2 of the relay L. öas Retejs L holds the separating layer.

serves to reverse the polarity of the single current line, so that in contrast to this, in the case of the FIG. 1 in the connection establishment of the motor of the telex- xo set arrangement with simultaneous occurrence? machine Fs is switched on and the idle state of character current in the outgoing four-wire current flows through the receiving magnet EM and branch and isolating current state in the incoming when the connection is disconnected, the motor is switched off and four-wire branch which is restored via the lines al, bl other idle state; In addition, coming double current characters in single current switches on the relay L ilen holding resistor Rh , which converts 15 characters and prevents the Eir.rich converting them from the occurrence of reflections. The red, that is, the telegraph receiving relay B, win; nicht lais L recorded a pick-up delay of around 60 ms in the separating layer.

and a fall-out delay of awa 600 ms. Except- The invention is characterized in that Re-

the converter circuit US contains the relay R flexions are prevented without a time over-

with the windings I and II and the associated ao wachung using the relay R according to

Contacts r 1 and r 1. When establishing a connection F i g. 1 must be carried out, which only after a

the relay R responds with a delay, so that the contact responds with a delay time of hO ms and after one

r 1 only drops after a delay time of about 60 ms drop-out delay of about 300 ms. By

moved from the position shown and the omission of the relay R in the invention results

Winding I is no longer short-circuited. The REAS thus a simplification of the signaling process.

lais R has a dropout delay of about 300 ms. This is particularly advantageous when using the

so that the holding resistor Rh when the invention is released in conjunction with an electronic

Is no longer connected. Would a switching system with larger transmission

the holding resistance Rh works according to the final calibration speed. The invention enables

if the subscriber station Tn did not give 30 the end signal withdrawal at any time,

It is expedient to use a l.logic-

isolating current polarity sent to the central point to provide a circuit that has a single current

Trigger gnal, the input and output via the lines al and bl and one double-current-side each

transmitted to the exchange and has there as an input and output. This logic circuit

Terminating signal would be interpreted. 35 contains a trigger stage, the input of which is sent to the output

In the following text, binary signals from a voltage divider and a single current are often mentioned, with the help of which one of two binary values is connected and transmitted. One of these binary values corresponds to its output at the double-current-side output, the character current polarity, which is connected to the logic circuit as a 0 signal. In addition, it is net. The other binary value corresponds to the 40 a transistor stage is provided, the emitter-Kol isolating current polarity, which is referred to as a 1-signal. lektor route in series to the voltage divider to which the illustrated position of the contacts represents the pole of the operating voltage source is connected. Retirement, during which no messages are transmitted while the double-stream side input and the and via which the lines al, bl and double-stream side output of the logic circuit via a 2, b 2 each send 0 signals (character stream) to a gate to the base of the Transistor level can be specified. When the connection is established, i.e. closed.

Write state, is transmitted over the lines al, bl and The logic circuit is characterized by the Είπα 1, bl each a 1-signal (isolating current). set of electronic components in place of the mechanical telegraph relay with the help of the line completion resistor R 1. In the invention, the line current is set. The Nachbildwider- 50 is thus used only a single relay, which carries out the stand Rn is used to compensate for minimal F.mp polarity reversal of the single current line. The capture distortion. This relay works when establishing a connection and when

The in F i g. 1 shown known arrangement connection cleardown only once and is thus far the disadvantage that they are maintenance-free with several relays.

The following are some examples of the requirements and are therefore undesirable. In order to make the connection based on FIG. 2 to 4 explained, where Interrupt the connection by counter-sliding to the same counter-ability shown in several drawings, special relays with specific statuses must be identified by the same reference symbols Entitlement and dropout delays may be provided. are. Show it:

The invention is based on the object of providing eire 60 F i g. 2 a first embodiment in prin-

Circuit arrangement of the type cited above,

indicate those with a smaller number of Re- F i g. 3 timing diagrams of signals and switching

Lais works and gets through minor technical positions on the basis of which the operation of the in F i g. 2

Effort. In particular, the arrangement shown in the invention is explained and

Application is based on the task of developing a circuit arrangement. 4 a second embodiment in electricity

the relays A, B and R of the sequence display.

familiar arrangement is not required. F i g. 2 shows the logic circuit LOG, which

According to the invention, in a circuit arrangement, via the circuit point c and via the switch

S 6

Switching contacts u 1 and w 2 to the subscriber station Tn signal Ek = I at the base of the transistor 7Ί is this

and on the other hand via the circuit point d or e conductive, and'die operating voltage Ub is applied to the

to the double current line SD or to the gate G 4, two resistors R 3 and R 4 are shared. It is

connected. The double current line ED is the amount of the resistor R 4 significantly greater on the one hand with one input of the gate G 4 and 5 than the amount of the resistor R 3.

on the other hand with the input of the time stage L. The states of the trigger stage Tr, in which this

bound. The relay U controls the contacts u 1 and emits a 0 or 1 signal via its output,

u 2. The logic circuit LOG consists of the trigger, which is referred to below as a 0 or 1 state,

stage Tr, the transistor Tl, the voltage divider The threshold value of the trigger stage Tr is set so that

from the resistors R 3 and R 4 and the NAND ίο that the voltage drop across the resistor R 3 and on

Gate Eq. Collector of transistor Tl with applied 0-Si

If a 1 signal on the input side of the timing stage L is not sufficient to put the trigger stage Tr in its signal, for example a signal with a positive isolating current 1 state. If the trigger polarity output is longer or shorter than 60 ms, then gerstufe Tr and the line Sd becomes a 0-Si, a 1 signal 15 signal, i.e. negative symbol current polarity, is output via the output of the timer .L, or 0 signal emitted. If at the input of At time 1 1 the subscriber at the time stage L expresses a 0 signal, that is, a signal from negative subscriber station Tn , to send a telex character stream polarity longer than 600 ms or shorter ben. The calling subscriber presses a 600 msec, then a 0 signal or a 1 signal is emitted via the output of the timer L, not shown, located in the remote switching device Fg , ao call button, and the transmission contact SA- is closed - the output of the timer L is one hand to the switching device so that the remote operation from the rest Fg working winding of the relay U and on the other hand with current 4OmA JM flows through sen. The contacts connected to the exclusive OR gate G 4. u 1 and u 2 are in the position shown in full.

In the following, the mode of operation of the in F i g. 2 The voltage drop in the resistor R 3 increases, the arrangement shown in FIG. 3 represents »5 and the trigger stage Tr flips into the 1 state and explained timing diagrams. In FIG. 3, a 1-signal is sent to the switching center via its output. The signals with the same reference symbols are given. The exchange recognizes the call net as well as the lines over which the signals in FIG. 2 of the subscriber and sends its part at the time to be transmitted. For example, in FIG. 3 12 a selection request pulse ED with a signal ED shown over the duration shown in FIG. 2 of about 25 ms. Transferred to the election request line ED. The two binary values of the pulse at time 12 have the effect that a 0 signal is emitted via the output signal ED in FIG. 3 with the reference symbol 0 of the gate G 1, wound 1 is shown. The Si shown in Fig. 3 through the transistor T 1 for the duration of the selection signal U relates to the relay U, the demand pulse blocking and the current Jm below the C-O value the switched-off state and the 1 value 35 is broken . The interruption of the current Jm means that the relay U is switched on. is remote from the acoustic device Fg Wahlaufforden ^ The signal Ek the operation characterizes the counted, and it is not shown Wählin F i g. 2 shown transistor T1. with the 0-disc released. At the time / 3, the or 1-value of the blocked or the conducting calling subscriber selects the call number of the desired emitter-collector path of the transistor T 1 ent- 40 subscriber. After the exchange spoke to the. The in Fig. 3 has called the called subscriber in the diagram EM shown in FIG. 3, it sends the caller, identifying the operating state of the subscriber shown in FIG . According to the The time step L tilts in its 1 state, since a 1 -Si-0- and 1 is the value in Fig. 2 shown recom- gnal longer than 60ms is applied, and after a Dauei capture magnet EM respectively with no current . with stream 45 of about 60 ms is the time 1 5 via the off traversed the diagram SK and its 0- or gear of the time stage I. a 1 signal issued Re-1 values indicate the open or closed relay U responds and places the contacts u 1 and κ 2 in the contact path Sk in FIG. 2. In FIG. 3, the bottom is the position shown in dashed lines. Thus the EinVerlauf the current JM is represented with maximum fold power line Tl reversed. The current amplitude Jm of flies ■ + 40 mA and minimum amplitudes 50 from time 1 5 into the other direction by von-4OmA. the remote control unit Fg. and the motor remote

Up to the time 1 1 and the degraded state typewriter Fs will start. At time t S is

the connection between the subscriber station Tn thus the connection between the two subscribers

and the exchange displayed. The lines are built up and the write status is reached. Of the

SD and ED each transmit 0 signals. The motor 53 subscriber at the subscriber station Tn writes. That

the teletypewriter FS is at a standstill, and the first send 0 signal sent by the calling subscriber

contact & t is open. The remote switching device Fg causes a 1-state of the trigger level Ir, so that

from a small negative quiescent current Jm through the gate Gl receives a 1-signal and also from the

raft. Output of the gate Gl a 1 signal to the tran-

Since a 0 signal is transmitted via line ED 60 sistor 71 is output, which conducts transistor 71

is also due to the two inputs of the generic power. This interrupts the ED line.

ters G 4 in each case 0 signals, and via the output chen, and the transistor 71 remains in the

of the gate G 4 is a 0 signal to the gate G 1 conductive state.

transfer. Since the remote part 0 signal called at time 16 is also transmitted via line SD , the two recipients at the remote station wish to bypass gate G1 in each case 0 signals, so that about reverse direction via the line ED signals to the output of which a 1-signal is transmitted, as is transmitted. The remote party presses a signal Ek not shown in FIG. Key on his teletypewriter represented by the Si, and

an O signal arrives on the line ED. As long as machine writes Fs. Between the times / 16 the calling subscriber emits a 1-signal, occurs and / 17 the remote calling in this case writes no effect of the subscriber received via the line ED. At time 1 17 the remote Tcil-O signals. Only at the time 1 7 is the transmitting party has the clearing signal, so that the Vermittkontakt closed Sk, the trigger stage Tr is responsive, 5 of the subscriber station switching center Tn at the receiving and at the transmitting line SD is a 1 signal exceeds line ED is an O -Signal transmitted. After a contract. At this point in time the gate G 1 is given a delay time of about 600 ms at the time when an O signal is output at the output point / 18, the time stage L , and the relay U drops and the transistor Tl blocks. From the point in time / 7 onwards and puts the contacts mI and u2 back into the position, the transmission line SD is no longer fully marked on the transmission connection. At time / 19 the clock Sk is connected and it is cleared regardless of the connection, and a 1-Si signal is constantly transmitted on the Scndc line 3D of the position of the send contact Sk and a 0 signal is transmitted on the receive line ED. The punched tape, not shown, transmits signals.

The transmitter in the teleprinter Fs is, if necessary, F i g. 4 shows a further embodiment. It stops. From time / 8 onwards, the remote part 15 in FIG. The transistor stage shown in FIG. 2 with the receiver via the exchange to the calling sistor T 1 correspond in FIG. 4 the transistor Γ1, subscriber. The transistor Π opens and closes the resistors Λ 17, R 18 and the capacitor of the received steps, C 3. The RC element with the resistor R 18 and via the receiving magnet EM weakens the capacitor C 3 the message captured by the voltage peaks is printed. 20 that depends on the inductance of the typewriter

At the point in time / 9, the calling part now gives origin, and thus protects the transistor T 1 from receiving a counter-write signal via the communication of a destruction. Via the terminals / and g is put from the non-illustrated remote subscriber, subscriber in question with his in Fig. 3 dargedas by pressing one of the Feinschreib- button presented remote switching device Fg and its teleprinter Fj and by opening of the transmit clock 5aR overall 35 machine Fi connected. About the Umschalikon happens. As soon as the send contact Sk is open via clocks u 1 and u 2, the single current line around the receive line ED receives a 1-signal, polarized. With the resistor R 36 of the Linienwas in the time / Io is the case, the transit is current sistor of the supply voltage of + 120V T 1 locked. This means that what is generated for the opened one can be set to a certain value. Transmitting contact Sk corresponding 0-Signal 30 by turning on the embodiment shown in Fig. 2 trigger level of the trigger stage entspresprechen Tr Tr on the transmission line SD chen in F i g. 4 of the operational amplifiers OP that are given. The conductive connection of the Emp resistors R 5, R 6, R 7, R 8, R 9, R 10, R 11, R 12 catch line ED to the circuit point Ek is under- and R 37, the capacitors C 1 and C 2 and which broke, so that at the output of the gate C 1 a Zener diode Z 1. Before the trigger stage an off 1 signal is emitted and the transistor T 1 is connected to the resistor R 37 and the capacitor C 1 is conducive to a limited extent. From time / 10 onwards, the standing low-pass filter is arranged, which flattens the edges of the calling subscriber to the called remote subscriber - incoming telegraphing steps, so that mer in the remote station. Prevents bruises and the influences of induction

At the time / 11 the calling participant gives the activity of the receiving magnet on the curve shape a final sign. To do this, he presses his final 40 the telegraphing steps are eliminated. With this key in the teleprinter Fs and sends a low-pass filter, dynamic protection is achieved, with a 0-signal. After a period of about 350 ms rend with the resistor R 10 and the Zener diode - at the time / 12 - the switching center recognizes that Z1 has reached static protection. In the locked final signal and in turn sends to the subscriber state of the transistor T 1, a 0 signal arises with the resistance. Here, at time / 13 45, R 37 and the capacitor C1 at the low-pass filter, after a duration of about 600 ms, the time stage L to full operating voltage of +120 V. Via the resistor, the 0 signal and emits a 0 signal Resist R 7 is the current and with the help of the Zener relay U drops and controls the contacts u \ and κ 2 diode Zl, the voltage back to a permissible value in the fully drawn position. The single limited, occurring interference voltages direct current line Tl is polarized back again, and it 50 are also limited in time. The resistors R 8, the idle state prevails: the motor of the teletype R 9 and R 10 cause positive feedback on the Operamaschineff is switched off and the transmission line amplifier OP, so that the amplifier "already at SD and the receiving line ED transmit very small input voltages With the 0 signal. Capacitor CI is the positive feedback of the amplifier

From time 1 13 to time / 14, Beckers OP dynamically improved. With the resistances, the diagrams in FIG. 3 extend to the connection established RS and R 6, adding the voltage. If the remote subscriber wishes to set a threshold of +120 V, which is connected to the subscriber station Tn in a write input of the operational amplifier OP after selecting the effect. Only when the input voltage call number of the subscriber station Tn from the exchange 60 exceeds this threshold value does the operational station transmit a 1-signal, which occurs on the reception amplifier OP in response to the input signal and the reception line ED at time / 14. After working as a trigger level. The rectangular off delay time of about 60 ms gives the timing signal via the resistor R 11 to stage L at the time / 15 via its output on the transmission line SD. From the 1-signal shown in Fig. 2, the relay U responds, and via the 65 gates G 4 , the transistor T 3 in Fig. 4, contacts u 1 and u 2 in the dashed line correspond to the resistors R 13, R 19, R 20 and R 21, the neten position, the single current recovery Tl reversed polarity, Zener diode Z 2, the diode D 3 and the contact u 3. so that the motor starts and the teletype machine appears on The end-

ίο

output a 1-signal if one of the inputs has a 0-Si. When the connection is established, the receive signal is received and the other receives a 1-signal. From this, ED derives a 1 signal. The transistor 74 and the fact that when the relay U and da- diode D 4 responds are blocked. Thus, when the contact u 3 is actuated, the capacitor only charges the voltage at the capacitor C 4 via the resistor R 23 on a span receiving line with a potential of -12 volts. At the base of the transistor borrowed 0 and 1 signals either directly or negated 74 is using the resistors R 25 the second input of the NAND gate G 1 pulls and R 26 a fast value of about -5 V is set, leads. when it is exceeded by the capacitor discharge

The receiving line ED is across the resistor charge, the transistor 74 is conductive. The threshold R 13 directly at the diode D 2 when the contact u 3 io is reached after a duration of about 60 ms. The transistor 74 is in its conductive, fully drawn position of the contact u 3 , the state, and in the capacitor C 4 , the charge on the receiving line ED is kept constant in the voltage occurring in the position shown in dashed lines. The two downstream Tran transistors 73 are negated and transistors 75 and 76 are fed in via the resistor R 19 to form a so-called Darlingder diode D 2. With the diode D 3 and the 15 ton stage, which has a current amplification equal to the pro-Zener diode Z 2, a threshold value is set so that the duct of the two current amplifications of the two on the one hand causes a safe blocking of the transistor 7 3 '' transistors. The transistors 7 5 and 76 reached and, on the other hand, a response when opening is controlled to be conductive, so that the diode D 6 entered smaller interference voltages is prevented. With locks is. The transistors 77, 78 and 79 are connected to the resistor R 20, if the input current is now in the blocked state, the relay U drops out, and the resistor R 21 switches the blocking off, and the contact u4 switches to full drawn voltage supplied. Lie turned down on the two diodes. The capacitor C4 is thus switched off Dl and DZ each 0 signals or the combination is switched.

nation consists of a 0 signal and a 1 signal, so When the connection is disconnected, the gate becomes permeable via the receiver, and the transistor 72 »5 Interception line ED transmitted a 0 signal, so that it is conductive, which then also controls the transistor 7 1 in transistor 7 3 and the diode D 4 in a conductive manner and controls its conductive state. The diode DS and the transistors 74, 7 5 provided gates (7 Ϊ correspond in FIG. 4 to the tran- and 7 6 are blocked. Since before the transistor 76 sistor 72, the diodes D 1 and D 2 and the resistance was discharged, the capacitor C 5 is discharged through the levels R 14, RIS and R 16. With the help of the resistors, the blocking of the transistor 76, the capacitors RIS and R 16 are set a threshold value C 5 against a voltage across the resistor /? 28, which safely blocks the transistor Γ 2 and charges its voltage from -12 V. As soon as the threshold value set to the conductive state by means of small resistors R 31 and R 32 prevents interference voltages. The resistance ft 17 is equal to the capacitor charge, the transi enables a safe blocking of the transistor 71. The 35 interferes 7 7 conducts and keeps the capacitor charge on the time stage L shown in FIG U drops out of the transi disturb 74, 7 5, 76, 77, 7 8 and 79, and the contact μ 4 in the fully drawn position of the resistors R 22, R 23, R 24, R 25, R 26, the capacitor C 5 is over rapidly discharge the transistor controlled by the R 27, R 28, R 29, / 7 30, R 31, R 32 and R 33, derived from the input line ED, the capacitors C 4 and C 5, the diodes D 4, 40 76. The high discharge current is from DS and D 6 and the contact μ 4. The relay U the Darlington stage with the transistors 75 and responds only when the in F i g. 2 shown T 6 applied. In the write state, the capacitor timer L is charged with a delay of 60 ms or capacitor C 5 during the step duration; it responds with a delay of 600 ms. However, the response threshold of the transistor 7 7 switching to one of these two delays 45 is not reached. The charged capacitor CS must be discharged within a step duration with the help of the contact u4 of the relay U The charged capacitor CS, so that both delay times of 60 ms and 600 ms at an input current of about 100 μ when the capacitors C 4 and C 5 and the sistor 75 a current amplification of about 1000 associated charging and discharging resistors is required to ensure rapid discharge. The relay U is energized in the idle state. At 50 it is performing. This is achieved with the Darlington stage, the established connection requires the power supply. The resistor R 29 is used to limit the current for the relay V to apply no current. the Darlington stage with transistors 75 and

In the dismantled state, the contact u 4 is in the 76 when the capacitor CS is discharged. The position shown in dashed lines. On the on-diode Dl parallel to the relay I / protects the trunk line ED , a 0 signal is transmitted, which keeps the 55 sistor 79 from voltage peaks that keep transistor T 3 in its conductive state when it is switched off. Occurring due to the inductance of the relay winding. Diode D4 is conductive, and resistor R 23 is connected to it. It would also be conceivable to apply a voltage of 24 V instead of the one in FIG. The capacitor C 4 is set time stages with the transistors 74 and discharged, since at its two electrodes the potential 75, 76, 77, 78 and 79 is a differently structured tialvon + 12V. Use the diode D 5 and the Tran-So time stage without changing the mode of operation of the sistor Γ 4 are blocked arrangement to be changed ..

1 sheet of drawings

Claims (1)

P "tpntan_nrüf.h_. second switching contact (iil, u2) of the relay U to claims. dn television viewing device (Fg) one of the participant 1. Circuit arrangement for converting places (Tn) are switched on (FIG. 2). Telegraph characters between a two-wire 7. circuit arrangement according to claim 4 operated single current line and a four- 5 and 6, characterized in that the second wired double current line in gate (G 4) a second transistor (73) is provided Teleprinter systems, in which incoming dop- is seen, whose base with the double-stream side pelstromzeichen the transmission of the arriving input line (ED) is connected, whose coI- the single current symbol and incoming reader to a third switching contact («3) of the