US3005872A

US3005872A - Means for decoding signals telegraphed in binary code and for controlling teleprinters

Info

Publication number: US3005872A
Application number: US842988A
Authority: US
Inventors: Vierling Oskar
Original assignee: Individual
Current assignee: Individual
Priority date: 1958-09-30
Filing date: 1959-09-28
Publication date: 1961-10-24
Anticipated expiration: 1978-10-24
Also published as: FR1236861A; GB911826A

Description

0. VIERLING Oct. 24, 1961 MEANS FOR DECODING SIGNALS TELEGRAPHED IN BINARY CODE AND FOR CONTROLLING TELEPRINTERS Filed Sept. 28, 1959 3 Sheet ..s 1

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0. VIERLING Oct. 24, 1961 MEANS FOR DECODING SIGNALS TELEGRAPHED IN BINARY CODE AND FOR CONTROLLING TELEPRINTERS 3 Sheets-Sheet 2 Filed Sept. 28, 1959 d H" H W C 2 C W AI IHI 1 I II WIILW I I II I I Ir III[ c: :I 6:

Invenzorr Oct. 24-, 1961 o. VIERLING 3,005,872

MEANS FOR DECODING SIGNALS TELEGRAPHED IN BINARY CODE AND FOR CONTROLLING TELEPRINTERS Filed Sept. 28, 1959 S'Sheets-Sheet 3 6 I: 02 H I---d 0 E %N D7'II r/2 cc 773 Fig. 5

Invenfor:

LIL

ates

This invention relates to an arrangement for the translation (de-coding) of binary-coded telegraph signals in the form of n-digit impulse-element combinations, which are composed of n individual impulses of positive or negative potential following one another in point of time, particularly an arrangement for thecontrol of teleprinter receiving devices.

Ordinary teleprinting code signs, such as are transmitted as telegraph signals, are composed of a number of current elements of two dilferent potentials. Here the number of current element depends upon the code employed and upon the process of transmission. There is, for example, an internationally standardised five-unit binary code with two supplementary element, which serve for starting and for stopping the receiver. The duty of the receiver is therefore to convert, from time to time, a code combination of elements consisting of seven impulses into a form suitable for interpretation, and to feed it to an interpretation arrangement, in which the actual n-digit (for instance S-digit) code combination is identified (translated) and an actuating impulse is given to one of 2 (for instance 32) interpreting members, which immediately, it may be, prints in clear type a sign allocated to the code-element combination.

Now this invention relates to an improved interpreting arrangement which carries out the identifying (deciphering) of the coded signs, and can serve for controlling the interpreting members.

Arrangements which fulfil the said purpose are known in themselves. These known arrangements consist in general of electro-mechanical assemblies, in which a plurality of mechanically moved parts and almost exclusively mechanically moved contacts are employed. Thus the known arrangements necessarily exhibit the disadvantages of noisy wonking and heavy wear. They also require a considerable expenditure for supervision and adjusting work. Finally also the speed of working of the known arrangements for interpreting the code combinatios in comparatively low. It is therefore of interest to increase the speed of interpretation.

This invention provides a remedy by means'of an interpreting arrangement consisting of purely electrical constructional elements, the object of which is to obviate the abovementioned disadvantages.

In dividual constructional elements and assemblies of the electrical interpreting arrangement according to the invention are in themselves already known. Thus it is in case of need usual, in electronic technology, to employ so-called counting chains of relays, in Which each link of the chain contains a bi-stable or two-state connection. These connections are also constructed with semi-conductive elements. As bi-stable semi-conductive elements there are employed for example combinations of two junction transistors, or a point-contact transistor, or a double-base diode, or finally a so called switching transistor. All such bi-stable elements exhibit a negative resistance characteristic, and are substantially equivalent to one another. The links of the counting chain of relays are so controlled, by way of special switching elements it may be, that the impulses of a train of impulses arriving at the input of the counting chain of relays atent 3,005,872 Patented Oct. 24, 1961 are each supplied individually from time to time to a link of the counting chain.

The interpreting arrangement according to the invention for the interpretation (translation) of binary-coded telegraphy signals in the form of n-digit impulse-element combinations which are composedof n individual impulses of positive or negative potential succeeding one another in point of time, particularly an arrangement for the control of teleprinting receiving devices, is characterised essentially by a counting chain of relays connected to a supply line for the impulse-element combinations to be interpreted, thechain of relays comprising countingchain links which each contain two bi-stable semi-con ductive'elements, one of which can be switched by a positive impulse and the other by a negative impulse; impulse gates which are controllable by the countingchain links and which supply the impulses of the n-digit impulse-element combinations arriving in the arrangement individually in succession each to one of the counting-chain links; a selective branching connection branching stepwise up to a maximum of 2 outputs, in the branching stages of which are arranged electronic selective switching elements controllable stepwise by the impulse-element combinations substantially by way of the bi-stable semi-conductive elements of the countingchain links, these switching elements selecting one of the outputs by means of their impulse-dependent control; interpreting members individually connected to the outputs of the selective branching connection, of which the particular one that is located on the selected output is actuated by an actuating impulse released by the last impulse of the impulse-element combination; and a resetting appliance restoring the arrangement to the initial position after the interpretation of an impulse-element combination.

Owing to the fact that in the links of the counting chain there are two bi-stable semi-conductive elements, the part of the arrangement following the counting chain and connected to the links of the counting chain and constructed in the manner of a selective branching connection with electronic switching elements is very easy to supervise; it preferably consists almost entirely of purely similar transistor stages acting in the manner of circuit-closing or double-throw switches. These transistor stages also admit at the same time of being utilised as amplifiers for an actuating impulse to be passed on by the selective branching connection.

A further advantage of the arrangement according to the invention is given by 'the' fact that the succeeding transistors of the branching connection are connected directly, that is, without the interposition of galvanically coupled intermediate stages, with their tendency to cause drift phenomena, to the counting-chain links, and the counting-chain links are not overloaded as regards power.

In a further development of the invention the transistors located in one branching stage of the branching connection are each biased by a bi-stable semi-conductive element of two successive counting-chain links in such a way that they exhibit a working point suitable for amplification onlyswhen the bi-stable semi-conductive elements of both the counting-chain links are in the reversed condition.

With the entry of the impulses of a code signal impulse train, therefore, definite transistors, given or selected by the sequence of impulses, in the branching connection, are brought out of the blocked condition into a working condition.

In the case of a preferred form of construction of the invention, the transistors, adjusted by the bi-stable semiconductive arrangements to the desired working point, are supplied with the last impulse of an iu-coming code signal, which then follows, with simultaneous amplification by the transistors, the path prepared in the branching connection by the sequence of impulses received, by way of the last branching stage (in which it may itself determine its further path by its own polarity) and actuates the selected interpreting member. The transistors are so coupled or connected in groups that for the reception of code element combinations with an even number of elements, one transistor is allocated to each in-corning element combination, whereas in the case of code-element combinations with an odd number of elements, one transistor is allocated in each case to two combinations of elements differing only with respect to the polarity of the last element, on the collector of which transistor, upon the arrival of the combination in question, the last impulse thereof appears in amplified form. The further selection that is necessary in code-step combinations having an odd number of elements is effected in the last stage of the branching connection, preferably with the help of two oppositely polarised transistors or semi-conductive diodes each. i

From the transistors or the semi-conductive diodes to the outputs of the branching connection, the impulses, preferably already amplified in the branching connection, pass to members for the clear-script reproduction, for instance to the type magnets of a printing appliance, an electrical typewriter for example, which writes in clear script the messagesreceived.

The positive and negative impulses of the individual code combinations, to be utilized or dealt with by the arrangement according to the invention, are converted from the incoming telewriting signs, in a known and conventional manner, for instance by amplifying, limiting and differentiating, into trains of impulse elements with sharp positive and negative individual impulses. In so doing, any starting and blocking steps that may be present at the same time are separated out, so that to the interpreting arrangement according to the invention only the actual code-element combination of n impulses is supplied.

The invention will now be further explained with reference to the accompanying drawings, in which:

FIGURE 1 shows a diagrammatic and greatly simplified circuit diagram of an interpreting arrangement according to the invention for telegraphic signals of a binary code with five-digit element combinations, which can be used for instance for the control of an electrical typewriter;

FIGURE 2 shows a greatly simplified circuit diagram of an interpreting arrangement which works according to a principle similar to that of the arrangement in FIG- URE 1, but needs fewer switching means in the branching connection;

FIGURE 3 shows a detailed circuit diagram of the most important part of the interpreting arrangement of FIGURE 2;

FIGURE 4 shows a detail of the connections of the arrangement according to FIGURE 2; and

FIGURE 5 shows a detail of the connections to be optionally or selectively employed in the arrangement according to FIGURE 3.

FIGURE 1 shows, at the left-hand margin of the figure, the counting chain of relays consisting of five links A to A to the input L of which the trains of impulse elements are applied, which, before entering the input L, have been amplified, limited and differentiated, by known devices, not shown. As an example of such a train of impulse elements, beside the input L of the counting chain the impulse train S is marked, which is composed of two negative impulses, followed by a single positive, then again a negative, and finally a positive single impulse.

The closure of the counting chain is formed by the link A the object of which is to return the counting chain into the original condition after the passage of the impulse train S.

On the right, beside the counting chain, is shown a selective branching connection, which, in the case of this example, serving only for the purpose of explaining the fundamental method of working, for the purpose of simplifying the representation, may be fed from a battery B by way of a switch E. The selective branching connection contains in each branching stage switching means of an electronic nature, which in the position of rest are open, and which from time to time, in stages, by the links A to A of the counting chain switched by impulses, can be brought into a condition in which they prepare one of two possible current paths within the stage in question of the branching connection.

Thus the first electronic switch F is dependent upon the first counting-chain link A while the two switches G and G of the second stage are dependent upon the counting-chain link A The switches H H H and H are controlled by the counting-chain link A the countingchain link A, controls the switches I to 1 and the last counting-chain stage A controls the switches J to J To the two output contacts of each of the switches J to J of the last stage of the branching connection, interpreting members K to K constructed for instance as type magnets, can be switched on, and these in their turn are all connected to the other pole of the battery B.

According to the invention the links A to A of the counting chain (the construction of which will be gathered from FIGURE 3) contain in each case two bi-stable semiconductive elements, one of which in each case is switched over by a positive impulse and the other by a negative impulse. By this change-over of one of the two semiconductive elements of the counting-chain link in question, this counting-chain link is at the same time, in a manner to be hereinafter explained, blocked against further impulses, and a succeeding impulse is fed to the next counting-chain link, in which, according to the direction of the succeeding impulse, a change-over of one of the two bi-stable semi-conductive elements of this link is then likewise efiected.

The semi-conductive elements of each counting-chain link A to A now not in such a way upon the switches of the stages F, G, H, I and J of the branching connection that each switch of one stage is brought, by a negative impulse on the counting-chain link allocated to the stage in question, into a condition in which it establishes a connection with the left-hand branching conductor, whereas with a positive impulse it establishes a connection with the right-hand branching conductor.

When the train of impulses denoted by S is received, the first negative impulse occasions, in the counting-chain link A the response or change-over of the bi-stable semiconductive element of this link reversible by negative impulses. This in its turn controls the switch F to the left into the condition shown by a dotted line. The second negative impulse is operative in the counting-chain link A and this likewise throws over the two switches G and G to the left. The third impulse, positive, then following, brings about, in the counting chain link A a response from the semi-conductive element, which is reversible by a positive impulse, and which in its turn throws over all the switches H to H; to the right. The succeeding impulse, negative, evokes in the countingchain link A,, the response of the bi-stable semiconductive element reversible by negative impulses, which in its turn throws over to the left all the switches I to I In the last counting-chain link A the last impulse, which is positive, releases a reversal of the switches I to I to the right.

In the branching connection, dotted lines are employed in each case to represent the conditions of only those switches F to I which become operative in the selection of the interpreting member allocated to the impulse sequence S. These are the switches F, G H I and 1 It is recognised, provided the switch E is closed, that by the impulse train S a connection is established between the branching-connection input connected to one pole of the battery B and the interpreting mer t ber K which is connected to the other pole of the battery, and is consequently-actuated by closure of its actuating circuit when the switch 1;, is thrown over. The interpreting member K if it is a typing magnet of an electrical typewriter, prints a definite sign, for instance a letter corresponding to the impulse sequence or to the code-element combinationv S, in a known manner. All the other interpreting members K to K and K; to K remain at rest, since, as can easily be seen, their circuits are not closed.

By the last counting-chain link A on the other hand, the counting-chain link A is also controlled, which, immediately after the response of the interpreting member K restores all the counting-chain links. By this restoration of the counting-chain links, the switches of the stages F, G, H, I and J are also all brought back to their initial positions, in which all the branching places are interrupted.

Reference may be made to the fact that the switches of the stages F, G, H, I and I in the branching connection, shown as reversing switches for the purpose of simplifying the representation, are in fact not mechani cally switching contact appliances but electronic arrangements known in themselves, particularly transistor arrangements, which are controlled by the bi-stable elements of the counting-chain links in such a way that they carry out the functions of a reversing or change-over appliance. Since, as it known, transistors or transistor arrangements can be controlled with a small expenditure of controlling energy, there is no risk of overstressing the counting-chain links, particularly the last countingchain link A which has to control sixteen such arrangements at the same time.

Further details concerning the manner of connecting or influencing the transistor arrangements of the branching connection are given later on, in connection with the descriptio of FIGURE 3.

From FIGURE 1, which has just been described, it will be seen that the number of transistor change-over appliances in the branching connection is comparatively high, since in each successive stage of this branching connection the number of change-over appliances is doubled. If it is desired to employ transistors of as normal a kind as possible in the branching connection, two such transistors must moreover be inserted for each change-over appliance. This means that for the branching connection according to FIGURE 1, altogether transistors are required, if five-digit code signals are to be de-coded'or translated.

By the aid of an arrangement such as that shown in FIGURE 2, the number of switches needed, particularly the number of transistors in the branching connection, can be reduced, and furthermore the method of working of the interpreting arrangement as a whole can be simplified and improved. I

With this arrangement, two sucessive links of the counting chain act in each case jointly upon one group of switching means in the formof transistors acting as circuit-closing switches, which, within the branching connection, in each of the two stages P and Q, select in each case one of four possible paths.

'In this constructional example of the invention, the counting chain consists of fivecounting-chain links N N ,N N and N of which the links N and N act jointly upon transistors of the group P (P P P and P while the two following counting-chain links N and N act upon the transistors of the group Q (Q Q Q The last stage of the branching connection, which in this example consists of the sixteen switches U to U represented as change-over switches, is now however not controlled directly by the last counting-chain link N In'this last stage, only changeover means that respond to the polarity of an impulse traversing the branching connection are provided. 7

This impulse is guided by the last counting-chain link N preferably acting only as a gate, into the input of the branching connection (input of the group P) amplified within the branching connection in transistors of the groups P and Q which determine in each case the selected path, md then passed on, in one of the change-over means of the group U, to the member selected from the interpreting members K to K By the last impulse the switch E is also closed, so that an actuation of the selected interpreting member is effected.

Exactly as in the example according to FIGURE 1, a restoration of all the links of the counting chain is also required in the arrangement according to FIGURE 2, after an impulse train S has passed through. This purpose is served by the restoring appliance R. In this restoration, the transistors of the groups P and Q, which had been brought by an impulse train S into the conditions symbolized by the dotted switch positions, also go back into their open initial conditions.

With reference to FIGURE 3, which represents in detail the circuits of the arrangement of FIGURE 2, the fundamental structure of the counting-chain links, and the co-operation of each two counting-chain links with groups of four electronic switching means, only one of which is selected and actuated according to the incoming impulses, will be more fully explained.

FIGURE 3 shows towards the upper left-hand corner the input L, consisting of an input condenser, of the counting chain embracing the four links N N N and N and also the last gate-link N The first four links N to N of this counting chain each comprises two bi-stable semiconductive elements in the form of transistors T T T3, T T T and T T while the last counting-chain link N contains only one gate-diode.

The transistors T to T of the counting-chain links N to N, are coupled, for the purpose of correct stepwise advance of the counting-chain links by the impulses arriving, with gate-diodes D D D and D The transistors are adjusted, by suitable dimensioning of their resistances (Wc=joint collector resistance, Wb=base or ground resistance, and We=emitter resistance) to a oi-stable working characteristic. In the state of rest of the arrangement, all the counting-chain transistors are in the blocked condition.

Between the input L of the counting-chain connection and the gate-diodes D D D and D are located blocking condensers C, which are necessary in order to enable the diodes to be opened or closed independently of one another by appropriate bias voltages. Beyond each of the diodes D to D are located further blocking condensers C in the control conductors for the reversal of the bi-stable transistors.

On the outer voltage connections of the circuit are marked the letters a to e, which are to indicate the relative level or value of any voltages to be applied to these points. By way of elucidation, to the right in the middle of FIG- URE 3 a source of voltage B (as a battery) is represented. This supplementary FIGURE shows that the point a has the highest positive potential and the point e the highest negative potential; and the points b, c and d denote intermediate voltages diminishing in that order.

The transistors T to T are all, as their emitting arrows indicate, NPN transistors. Their collectors therefore have the highest positive voltage.a,-while their bases have a voltage d lower than that of their emitters, which are connected to the point 0. In the counting chain the feed voltages of the links diminish stepwise from link to link.

The gate-diode D allocated to the first counting-chain link N is connected on the one hand by way of an adjusting resistance Wd with the two collectors of the transistors T and T and on the other hand, by way of a second resistance Wd with the voltage point b. Since the col- 'lector potential (a) in the state of rest of the counting chain is higher than the potential I), the diode D has a voltage bias in the conducting direction. It can therefore transmit an in-coming impulse.

Each of the diodes D D and D is connected on the one hand, by way of a resistance Wd or W11 or Wd respectively, with the collectors of the transistors of the particular preceding counting-chain link, and on the other hand, by way of the resistances Wd, with the collectors of the transistors of the associated counting chain link, the idle voltage of which is in each case somewhat lower than that of the preceding link. The last diode D is connected by way of the resistance Wd to the collectors of the transistors of the counting-chain link N and on the other hand, by way of the resistance Wd, with the voltage point 1'). The diodes D to D are therefore, in the state of rest of the arrangement, biased in the blocking direction, and therefore blocked against in-corning impulses.

In the right-hand side of FIGURE 3, above, is represented an input stage P, consisting of four transistors P to P of the branching connection. In the middle there is the part of the second stage Q of the branching connection which is connected to the transistor P and is built up from the transistors Q to Q and which also embraces three further parts, correspondingly connected to the transistors P P and P with the transistors Q5 Qs Q9 Q12 and Q13 Q16; and right at the bottom is represented a switching means, consisting for example of two mono-stable transistors T and T of the last branching-connection stage U; the two transistors T and T one (T of which responds only to a negative controlling impulse, and the other (T only to a positive controlling impulse, forming together the switching means U Finally to the two transistors T and T are connected two interpreting members K and K All the transistors of the branching connection are in the blocked condition.

The emitters of the transistors P to P are connected in cyclic order, by way of two potentiometer resistances Wp each, to the emitters of the bi-stable transistors T to T so that in the state of rest the emitter potentials of the transistors P to P lie far below the potential of the bases of these transistors. The same applies to the transistors of the Q-stage of the branching connection, the emitters of which are correspondingly connected by way of the potentiometer resistances Wq to the emitters of the transistors T to T For the explanation of the method of working of the connection let it be assumed that at the input L of the counting chain there arrives a sequence S of impulses, as indicated at the upper left-hand corner of FIGURE 1. This train of impulses has the combination The negative impulse arriving first passes through the diode D biased in the conducting direction, and loads, by way of the two blocking condensers C of the countingchain stage N both the emitter of the transistor T and the base of the transistor T The negative impulse re duces the voltage of the emitter of the transistor T so far that this voltage falls to about the potential d of the base, and therefore the transistor T abruptly reverses from its stable condition of rest into a likewise stable unblocking condition. The negative impulse simultaneously coming on to the base of the transistor T has no action on this transistor, since it merely reduces the base potential further.

Owing to the fact that the transistor T is conducting, the potential at the two collectors of the transistors T and T falls in consequence of the load current, and the potential at the emitter of the transistor T increases. The fall in the collector potential is here so marked that the voltage applied by way of the resistance Wd to the positive pole of the diode D drops below the value of the voltage point 12, and therefore this diode is biased in the blocking direction, so that it is blocked against 8 further in-coming impulses. Since the transistors T and T have a common collector resistance, when one of them is switched on the characteristic of the other also shifts so far that an additional changeover owing to the voltage impulses occurring upon the blocking of the diode D cannot occur.

At the same time, however, the fall in the collector potential in the counting-chain stage N causes an unblocking of the diode D which had been biased in the blocking direction by the difference between the collector potentials of the two counting-chain stages N and N This opening of the diode D admits of being delayed by known measures, for instance by the selection of highohmic resistances Wd, until the first impulse has completely faded away. In addition the change of voltage is effected so slowly that the operation of opening has no reactions upon the transistors of the counting-chain link N2.

The second negative impulse now arriving passes by way of the unblocked diode D to the emitter and to the bases of the two transistors T and T of the countingchain link N It changes over, of these two transistors, the transistor T which is sensitive to negative impulses, as the result of which, on the one hand the potential at the emitter of this transistor rises, and on the other hand the potential at the collectors diminishes. This diminished collector potential now efiects in its turn a renewed blocking of the diode D and, by way of the series resistance or compensating resistance of the succeeding diode D effects a delayed opening of this diode, which thus sets free, for the next in-coming impulse, the path to the counting-chain stage N Before however going further into the method of working of the counting chain it is first of all to be explained how the two counting-chain links N and N now act upon the input stage P of the branching connection. By the first negative impulse the emitter voltage of the transistor T had been increased, and by the second negative impulse the emitter voltage of the transistor T had been increased. By the simultaneous rise of these two emitter voltages, the emitter potential of the first transistor P of the input stage P of the selective branching connection is raised so far above the potentiometer resistances Wp, which are brought, at their two outer terminals, to a relatively high potential, that this transistor comes to its normal working point, corresponding to a usual amplifietion The other transistors P P and P of the first stage P remain however in the blocking condition, since the change in their emitter voltageseifected by any onesided increase of the potential at one of the outer connections of their emitter potentiometer resistances Wp does not sufiice to control these transistors into their normal working range; for on the transistor P there acts only the positive emitter voltage of the transistor T while on the transistor P there comes into action only on one side the positive emitter voltage of the transistor T The emitter potential on the last transistor P4, of the stage P does not change at all. By the co-operation of two negative impulses and the bi-stable elements T T T T of the first two counting-chain links N and N therefore, a selection has been made from amongst the switching means of the first stage P of the branching connection, which has set merely one of four switching means in a working condition.

In a corresponding manner the two succeeding impulses now act in the counting-chain links N and N and also in all the sections or groups, each embracing four switching means, of the second stage Q of the branching connection.

The third impulse, which has been assumed to be positive, and which comes by way of the diode D to the emitter of the transistor T and at the same time to the 'base of the transistor T this time changes over the transistor T responding to positive impulses, and thus increases one-sidedly the emitter voltages of the two transistors Q and Q and also of the othercorresp'onding; transistors ofthe branching stage Q, up. to a value which however is still not high enough to put one of these transistors into the working condition. The negative impulse now following, which impinges upon the counting-chain link N switches the transistor Tq into a conducting condition, and thus causes an other-sided increase of the emitter voltages of the transistors Q and Q in the first section, as well as of the corresponding transistors in the other sections of the switchingmeans stage Q. Since the transistor Q is connected only on one side with an emitter at higher voltage of the counting-chain links, it does not come into its working range. In the case of the transistor Q and also of the transistors Q Q and Q of the other sections, however, the raising of the emitter potential is effected from both sides, namely from the transistor T of the countingchain link N and from the transistor T, of the counting-chain link N The transistors Q Q Q and Q are therefore controlled into their working range. Of these, however, only the transistor Q continues the current path already predetermined by the transistor P in the branching connection right to the member U of the third branching stage U.

The last impulse of the impulse train, which is again a positive impulse, passes over the diode D which has meanwhile been opened, to the input of the first branching stage P, and acts upon all four of the bases of the transistors P to P It can only be eflective, however, on the transistor P as the transistors P P and P are still blocked by too low an emitter potential. The impulse, amplified in the transistor P and with its polarity reversed, then comes to the input of the section of the stage Q of the branching connection which contains the transistors Q to Q Of these transistors, the transistors Q Q and Q, are in the blocked condition, owing to the emitter potential being too low. Only the transistor Q is at a working point, so that it alone can transmit the negative impulse arriving at its base, as an amplified positive impulse, to the branching stage U consisting of the transistors T and T These two transistors, with respect to their collector, base and emitter voltages, are biased in such a manner that they are normally non-conductive. The transistor T can be put into a conductive condition transiently only by a negative impulse on its base; in the case of the transistor T a positive impulse upon the emitter is necessary in order to put the transistor transiently into a conductive condition.

The finally arriving positive impulse of the impulse train S will now therefore put the transistor T briefly into a conductive condition, so that this transistor delivers a current pulsation, which actuates the interpreting member K If this interpreting member is a printing magnet of an electrical typewriter, the character selected by the impulse combination will be printed by it.

In order that the change-over of the selected transistors of the Q-stage may not already lead to an unintentional response of the transistors in the U-stage, the voltage e on the transistors of the U-stage is first brought by the last impulse to that level at which these transistors can respond to an implified impulse coming from the branching connection.

The last impulse, which is passed by way of the counting-chain link N consisting only of the diode D also passes over the connection marked 0 at the left-hand bottom corner of FIGURE 3 to the restoring member R shown in FIGURE 4, which is likewise marked in FIG- URE 2. This restoring member R comprises three transistors T T and T of which the transistors T and T are together connected as a mono-stable multivibrator known in itself. The diodes D and D take care that a positive impulse arriving at the point 0 acts upon the base of the transistor T Whereas a negative impulse acts upon the base of the transistor T In both cases the mono-stable multivibrator is released, and to the collector of the transistor T is given an impulse X, which is represented in the right-hand top corner of FIGURE 4, and the duration of which is determined by a time-constant arrangement which consists of the adjustable resistance Wt and the condenser Ct.

The duration of the impulse X at the collector of the transistor T is so adjusted by the time-constant arrangement that the rear flank of the impulse occurs only when the printing of the sign in question is definitely completed. The impulse X is diiierentiated in the coupling condenser Co, and conveyed in the form Y to the base of the transistor T which is adjusted to its normal working point. Upon the arrival of the differentiated impulse Y upon its base, the transistor T is for a short time blocked by the second part of the impulse, and it then delivers to its collector a strong negative impulse Z. This impulse Z is given to the bases of all the counting-chain transistors; and the counting-chain transistors previously changed over are again set by this impulse into their original condition, that is, the blocked condition.

The voltages at the transistors of the branching connection are thereby also at the same time restored to their initial condition, so that all the transistors of this branching connection are blocked. The entire interpreting arrangement is then ready for the translation of a fresh train of impulses.

Finally FIGURE 5 shows in What manner the transistors (T and T in FIGURE 3) of the U-stage of the branching connection can be replaced by simple diodes D and D To each of the output transistors Q to Q of the Q-stage, diodes D and D polarized oppositely to one another are connected by way of a condenser C, these diodes each' being connected with one of the interpreting members, in the present case, K and K The last impulse, amplified in the P-stage and Q-stage, is therefore, according to its polarity, supplied to the interpreting member K or K I claim:

1. An arrangement for translating binary-coded telegraph signals in the form of n-digit impulse-element combinations, which are composed of in successive individual impulses of positive or negative potential, particularly an arrangement for the control of teleprinter receivers, characterised by a counting chain connected to the feeding conductor for the impulse-element combinations to be translated, with counting-chain links each containing two bi-stable semi'conductive elements, one of which is controllable into a conductive condition by a positive impulse and the other by a negative impulse, each counting-chain link also containing a first outlet conductor which is influenced by the controlling electrodes of the two semiconductive elements, and comprises two second outlets which are each influenced by only one semi-conductive element, by controllable impulse gates controlled from time to time by the voltage between a first outlet electrode of the counting-chain link to be controlled and a first outlet electrode of the preceding counting-chain link, so that the counting-chain links are switched over individually and successively, and further characterised by the feature that in the branching circuit, one outlet in each case of an element located in one group of switches is connected with the inputs of 2m elements of the following switch group, (m being a small integer) that each element has m inputs, that the inputs of all the elements of one switch group are connected with the 2m second outlet conductors of m successive counting-chain links, in such a way that each of the m inputs of an element are connected with one of the associated counting-chain links, that the inputs of the individual links of one group of switches are connected in a manner difierent from one another with the 2m second outlet conductors of the m counting-chain links, and that the first outlet of the last counting-chain link is connected with a switching element 1 1 for the purpose of controlling the latter, which is arranged between the input conductor of the signals and the inputs of the first group of switches, so that this switching element becomes conductive when the last counting-chain link is actuated, and that a device known in itself is provided which restores the arrangement into the initial position after the translation of an impulseelcment combination.

2. An arrangement for the translation of binary-coded telegraph signals as claimed in claim 1, characterised by the feature that as selective switching elements in the branching circuit transistors are provided, which are switched on from time to time in pairs in forked branchings of the stages of the branching circuit, and are coupled to the bi-stable semi-conductive elements of the countingchain link allocated to the associated stage of the branching circuit, in such a way that they are in a state of rest in a blocked position, and that only one transistor at a time of a pair of transistors is changed out of a blocked condition into a working condition in dependence upon the potentials of the coupling positions of the associated counting-chain link.

3. An arrangement for the translation of binary-coded telegraph signals as claimed in claim 1, characterised by the feature that as switching elements in the branching circuit, transistors are provided, and that the outlet of a switch element is connected each time with the four inputs of four associated switch elements in the succeeding group, that each switch element is provided with two input-control conductors, that all the input-control conductors of a group are so connected with the four second outlet conductors of two associated counting-chain links that in each case the two input-control conductors of a switch element are connected with the one outlet of the two asso- 12 ciated counting-chain links, that the input-control conductors of the individual elements in one group are connected in ways different from one another with the outlet conductors of the counting chains, and that the working points of the switch elements are so selected that a switch element is actuated only when voltages of definite polarity are applied to both its inputs.

4. An arrangement as claimed in claim 1, characterised by the feature that when employing an odd number of impulse-sequence elements, the last group of the branching circuit comprises only switches interconnected in pairs, one of which becomes conductive at a positive input impulse and the other at a negative input impulse, and that a switching device is provided which from time to time conducts the last impulse of a sequence of impulse elements to the input of the branching circuit.

5. An arrangement as claimed in claim 3, characterised by the feature that when employing an odd number of impulse-sequence steps, the last group of the branching circuit comprises only switching elements interconnected in pairs, of which one becomes conductive upon a positive input impulse and the other upon a negative input impulse, and that a switching device is provided which in each case conducts the last impulse of a sequence of impulse steps to the input of the branching circuit.

6. An arrangement as claimed in claim 1, characterised by the feature that as translating members, magnets of a sign-printing appliance, particularly one with an electrical typewriter, are provided.

References Cited in the file of this patent UNITED STATES PATENTS 2,628,277 Spencer Feb. 10, 1953