US2738498A - Process for the automatic production of scrambled impulse and signal sequences - Google Patents

Description

/ ,March 135-31956, w. LIEBKNECHT 2,

- PROCESS FOR THE AUTOMATIC PRODUCTION OF SCRAMBLED IMPULSE AND SIGNAL SEQUENCES Filed June 14, 1952 I N VE NTOR: Warn em LL'QAKnec/xl PROCESS FOR THE AUTOMATIC PRODUCTION OF SCRAMBLED IMPULSE AND SIGNAL SE- QUENCES States Patent Werner Liebknecht, Schaan, Liechtenstein, assignor to C. Lorenz Aktiengesellschaft, Smttgart-Zufienhausen, Germany, a corporation of Germany Application June 14, 1952, Serial No. 293,705'

6 Claims. (Cl. 340-345 In connection with statistics and for coding purposes, nonsystematic, random sequences of figures and letters are required to a constantly increasingextent.

These sequences have hitherto been produced in a very vis so simple and operates in such an easily supervised manner that in practice the random sequence derived is assured even in continuous service.

One embodiment of the invention is morefully described by way of example in the following. i

The complete assembly can be regarded as comprising two sections. generating non-systematic short electrical impulses, namely, the impulse transmitter. Section 2, which is'-a valve trigger arrangement with two stable, end positions,' is operated by these impulses.

The following detailed operation is produced by the constructional example: Upon operating the key Ta, the control voltage Ust. charges the condenser Cu and, through R1,, also the condenser Cm. When the voltage at CLZ reaches the igniting voltage of the relaxation oscillator valve 1, CLz is discharged. The valve I continuously gen- Section 1 represents an. arrangement for erates additional sweep voltage impulses as long as the 7 key Ta is closed and as long as energy can still continue to flow from the condenser Cu to Cm after the key is opened.

If the key Ta is operated for a predetermined time, the number of sweep voltage impulses generated by the valve I depends on a large number of other determining values as well as on the time 2, namely: upon the control voltage Ust, upon Cm, RA, Rn, Caz, CK, RK and above all upon all the momentary electrical working conditions of the relaxation Kipp oscillator valve I. As a consequence of this large number of non-systematic variables, when Ta is repeatedly actuated, the number of the relaxation oscillation impulses generated is subjected to non systematicfiuctuations even when the time t is constant.

In addition, when operating the arrangement in practice, the time 2 also undergoes small fluctuations when the key Ta is actuated rhythmically, so that in this way a further non-systematic variable is provided.

If the control voltage Ust is taken from the mains without stabilisation, the normal mains voltage fluctuation is obtained as a non-systematic variable. An even greater uncontrolled fluctuation is obtained if the output level of a noise generator (valve noise) or the noise of radioactive counting tube ampiifiers are also used for th control.

It has been shown by experiments that the large technical expense this would involve is not necessary, since it does not provide any improvement in the random sequence 2,738,498 Patented Mar. 13, 1956 2 for the complete arrangement. The non-systematic fluctuations of the other determining valves of the impulse transmitter are definitely sufiicient.

The valve II, which serves to amplify the voltage impulses, is acted upon by the relaxation oscillation valve I through the coupling condenser OK and the coupling resistance Rn. I

The impulsing of the trigger arrangement, which operates with the valves III and IV, is effected by the anode of the valve II. In accordance with the circuit arrangement, one of the said valves III and IV is always, blocked by the negative grid biassing while the other is open. If an impulse occurs symmetrically on both grids, the blocked valve is opened thereby and the valve whichwas previously open is closed.

Consequently, if an even number of impulses is sent to the trigger arrangement upon actuating the key Ta, the trigger arrangement is in the initial position again after the impulses have finished. On the contrary, an odd number of impulses causes a new end position.

In conjunction with the impulsing by the impulse transmitter, the trigger arrangement operates in the manner of an electrical dice, which swings rapidly backwards and forwards between its two end positions and finally, .according to the number of impulses acting thereon, remains stationary on even or odd.

According to the position of the trigger arrangement, the indicator relay R disposed in the anode circuit of the valves III' and IV positions its contact on positive or negative. i

If the key Ta is operated systematically by any technical control arrangement, there is obtained a non-systematic random sequence of positive and negative values, resulting from the non-systematic dispersions of the impulse transmitter.

It is only a duty of the normal switching technique to operate simultaneously 5 or 6 or any desired number of electrical cubes by the key Ta in order in this manner to establish, with one actuation of the key, for example, a complete five-unit or six-unit signal of the teleprinter art, that is to say, a number or a letter.

Accordingly, a complete five-unit or six-unit signal is also defined by 5 or 6 processes with one dice.

Since the electric valve circuits have only a very low inertia, the operating speed is substantially only limited by the inertia of the indicating relay R, where the result is not indicated by inertia-free indicator elements such as glow-discharge lamps and the like.

During tests, it was possible to carry out up to 500 operations per second. This corresponds in the five-unit code to an output of letters or figures per second.

As regards the technical execution and the method of operation of the electrical dice, it is immaterial whether ion tube trigger arrangements or suitable electron tube circuits are employed for generating the, electrical impulses. Similarly, it does not affect the method of operation it the trigger device in the electrical dice is built up of two mutually blocking electron tubes or only of one or more ion tubes.

The sequences of figures and letters derived with the electrical dice may be used in many ways as number tables for statistical investigations, as groups of figures or letters for the purpose of hand ciphering or they may be stamped in perforated tapes as five-unit signals for automatic ciphering and the like.

I claim:

1. A random digit selecting system, comprising a source of control voltage, a normally blocked generator, means associated with said source of control voltage to shockexcite said generator and cause it to deliver a short train of pulses per shock, whereby the number of said pulses amuse} J is"odd"or"even"at-random*dcpendingmn' momentarilrpre" vailing oscillating conditionsJof said generator, a counter circuit which is adapted to be controlled vdepending/as to whether the number ofjp'ulsesrofthepulsei'trains. applied is odd or even, and? means "applying said trains of pulses to said counter. circuit.

"2..'"A random digit selecting system, compris'ingadirect current source of control voltage, a. normally" blocked generator,'means keying said "clire'ct currentivoltage to shock-excite said generator and cause .it to deliver a short train of pulses 'per.ishock,l.whereby theinumber of said pulses is oddior 'e'VenJat-random depending on"'the.momentarily 'prevailingioscillating conditions. acounter cir- .cuit 'ulhich. is adapted to. be controlled depending as to whether"'the number *of pulsesiof 'the pulse trains applied is odd or even, 'and'means'applying said trains oi pulses to said counter circuit.

3. A random digit selecting system,.,cornprising'a random noise source, a normally" blocked; generator, .means applying the "output of. said. noise source to shock-excite said "generator and cause'it'to deliver a short train of pulses'per 'sho'ck,"wh'ereby'.the' number of saidpulses is odd or evenat random 'dependingonthe momentarily prevailing oscillating "conditions, a counter circuit which .is adapted'to be'controlle'd depending 'as'to whether the number of 'pulses'ofthe pulse trains "applied is. odd or evenyand means applying saidtrains of pulses to said counter circuit. 7

4. A random digit selecting system, comprising a source of "control voltage, a normallybl'ocked generator, means associated 'With'said source" of. control. voltage to shockexcite said generator, and storage means between said source of control voltage andsaid generator, said storage means comprising a first branch condenser, a resistance shunting-said firstbr'an'ch condenser, a series resistance auda second branch condensenthe charging. capacity of 'said first' condenserbeing sufii'ciently high to excite said generator further for a short timeinterval afterthe actual shock from said source of control voltage.

4 *5. *wrandonrdigit'selectingsystemr-eomprisinga'some of control voltage, a normally blocked relaxation generator, means associated with said source of control voltage.

to shock-excite said generator and cause it to deliver a short train of pulses pert;shock,i whereby the number of said pulsesmis oddfirfleven at random depending o n the momentarilygprevailingioscillating*conditionsrofsaidsgenerator, a counter circuit'a'daptedtd be controlled-depending as to whether the number of pulses of the pulse trains applied is odd iorszeven,v.-,ands.means tapplyinguasaidstmins of impulses-to said-"counter circuit.

6. A random digit'selecting system;='comprising asource of controlrvoltage;a;.generator of the gasdischagge type, storage means between said source of control voltage and said generator, means"associated with=-said source of conv trol voltage to shock-excite said generator and cause it to deliver a short train,of,pulses,pershock, wherebygthe number of said pulses is odd, or even at randomdepeliding on the momentarily prev'aiiling oscillating conditions, of said generator, an'amplifier stage, a counter, circuitsconsis'ting of ,a.,two-coridition-circuit adapted to be. triggered .byfthe pulses ofth'e pulse-trains suppliedfrom .sai'darn'plifierstage and to rest'in either of .itstwo stable conditions after a respective pulse train is'finished correspondingto its even-or odd number of pulses, means applying said trains of. piilses via said amplifier stage to the input of said counter.circuit, anda-relay connected to theoutput of said two-condition circuit and responding. to said two condition. 7

References Cited 'irrjthe" file 'ofthisgpatent UNITED .STATESPATENTS '.=2';40 6;0 31 EParker Aug. 20, 1946 Ex ,41.5, 09'3 tiGerwin Feb.4,'- 1947 539,014: :SzPrantz Jan.; 23, '1951 ,079 =Beaufoy Feb.' 12, 19.52

612L743 :tiStorther 'Oct.' 7551952 2,637,845 Craiglow May' '5, 1953

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