US2217957A

US2217957A - Wave-signal translating system

Info

Publication number: US2217957A
Application number: US275781A
Authority: US
Inventors: Harold M Lewis
Original assignee: Hazeltine Corp
Current assignee: BAE Systems Aerospace Inc
Priority date: 1939-05-26
Filing date: 1939-05-26
Publication date: 1940-10-15
Anticipated expiration: 1957-10-15

Description

1940' i v H. M- LEWis 2,217,957 WAVE-SIGNAL TRANSLfiTING 4 Filed May 26, 1 39 FIG. I.

INVENTOR H OLD M. LEWIS ATTORNEY Patented Oct.15,1940 V q I I I Y UNITED "STATES, PATENT. OFF-ICE] f 22,217,957. f Q a wAvE-smNAL 'rnANsLA'rmG SYSTEM H Harold M. Lewis, Great-Neck;N.lY., assignor-to A t 7 HazeltineCox-poration', a corporation ofDela-- i ware 1 W V.

a Application May 26, 1939, SerialNo 275,781

10 Claims. 101. 118;)

This invention relates to wave-signal -transand itsscope'wjl be pointed out in the appended" lating systems. ,The invention is especially conclaims, v v cerned with signal-translating"systems of the 'In the-accompanying drawing,Fig.'1 is acirtype adapted to effect predetermined time delay cuit'diagram; of anrelectric signal-translating sys a in the translation of signals. tem embodyingthe present invention: while Fig; Various systems have heretofore been devised 2 is a. group of curvesillustratingthe waveforms;

for the purpose of effecting timedelays in the of-wavesappeanng at various. points in thesystranslation of wave signals. Ordinarily, these tern ofzFig. 1 to aid in the understandingfof .the systems have comprised networks or transmission invention I V 1 a lines having input vterminals to which the sig-' Referring now more particularly to Fig; 1Qqf1 Q, nals are appliedand output terminals at their the. drawing, there is illustrated a wavesigna'l remote ends at which the delayed signals appear. translating system embodying, the present in;- 1 In order to obtain time delays of appreciable ventionand comprising an input circuit includ-I magnitude, it has been necessary to provide relaing a resistor, in connected by way of a coupling tively long transmission lines, either actual or condenser ll across a wave-signal source indi artificial, embodying a large amount of relatively cated at S. Connected tothe input circuit in, II expensive physical apparatus, the amount of apis a first signal-translating channel comprisinga paratus required being substantially directly provacuum, tube. I3 having its input electrodes con-9' portional'to the amount of time delayrequired. pled to the input circuit I0, ll byway of asuit It is an object of the present invention, thereable coupling condenser l4 and leak resistor l5.' fore, to provide an improved wave-signal trans- A second signal-translating channel is'also cou- Y lating system adapted to provide apredetermined pled to the-input circuit and preferably comprises time delay in the translation of a wave signal a polarity-reversing vacuum tube l6 having its and embodying a-relatively small amount of sphyscontrol grid connected to, a suitable tap 10a .on ical apparatus;v w the resistor l0;.and having a load resistor I] in 2 It is a further object of the invention to proits anode circuit. A-second vacuum tube'l8 is g I vide a system of the type described, characterincluded in the-second signal-translating chan ized by simplicity of construction, efiiciency in nei with its input electrodes connected across load operation, and adjustability for efiecting various resistor illsbyway of suitable coupling condenser o controlsof the translated signal. and leak resistor 20. Thetubes l3 and I8, are 39 In accordance with thepresent invention, there connected in parallel to a common outputcircuit is provided a wave-signal translating system comin ludin a S e e i t r 2| and inductance 2- prising an input circuit to which is coupleda re,- Preferably .the tub s and fa e a l o fi r fleeting delay network, preferably a dead-end filconventional pentode type havingsuitable potenter network,'adapted.to reflect the signal with a tials applied totheir screens from sources indipredetermined time delay. An output circuit catedfil'l In ac Ofthe O S dat is coupled to the input circuit for translating the Ode cum-fits of these P F a Suitable bias 913 delayed signal and the input and output circuits Such as a battery 1S 'mcluded- .Opemtmg are also coupled by additional means for neutral- .7 a I d a d and I8 from a-suitable,source 1nd1cated'at +3 40 izmg or substantially suppressing the un el ye by ay of me load resistdr. H and du n 22 signal. The latter means preferably comprise I g and tothe-tube l6 b wa of the load resistor l1. means for reversing the polarity of the undelayed For the purpose 3} efizctmg a predetermined j and m{ mm'the P delay in the translation ofthe wave signal applied with the undelayed signal of opposite polarity. 'to thevinput Qircuit In for the systemfthemis In a preferred embodiment of the invention, the p i {reflecting delay t rkyi c t remote end of the delay network is terminated mn t g'4 g r 24 omp a in an adjustable p d a means j P low-pass filter of the dead-end type, including i e for adjusting s p n t r input terminals 25 which are connectedacross tentials are applied to the anodes of thetubes l3 7 adjust the polarity an amplitude of the reflected the load resistor H by way of a suitabiecoupling 50 Wave- I l condenser Fla, and an input terminating resistor For a better understandingof the invention, to- 2B. The filter 24 as coupled to the inputtermigether with other and further objects thereof, nals 25 comprises an m-derived half-section conreference is had toth'e following description taken sisting of a shunt arm comprisinga series-conin connection with the a o p i draw g nected inductance zeand condenser 28 andase- 6 .7

ries arm comprising an inductance 21, coupled to a series of constant-k whole-sections individually comprising full-series inductance arms 30 and full-shunt condenser arms 3| and terminated in a mid-series inductance arm 32. Across the remote terminals of the filter there is connected an adjustable terminating impedance, for example, a resistor 33, the value of which may be varied over a wide range of values.

The operation of the system oi'the present invention may best be explained with reference to the curves of Fig. 2. While the system is adapted for translation of a signal of anywave .i'orm or frequency, for the purpose of'clarity, the

translation of a periodic rectangular-pulse signal is assumed by way of example. Curve A of Fig. 2 illustrates the appearance of such a wave as it may be supplied from the source S and impressed upon the input circuit I0, ll of the system. This wave is translated by the first channel of the system by way of the tube l3 with a reversal in its polarity so that its wave form,:as repeated by this tube, is as illustrated bycurve B. The wave is further translated by the sec'- ond channel of the system by way of the tubes l6 and I8, each of which effects a reversal in the polarity thereof, so that the signal-input wave as repeated by tube I 3 has its original. polarity, as illustrated by curve A, opposite to that which it has as repeated by the tube I 3. By properly proportioning the gain of the tubes It, IS, and I8, and adjusting the signal input to tube It by tap Illa, these two waves'may be made identical in amplitude but opposite in pop larity and, being combined in the additive common output circuit, they neutralize or cancel one another. The undelayed wave is thus substantially suppressed and does not appear across the output load circuit 2|, 22. The signal repeated by the tube It is also impressed upon the input terminals 25 of the delay network 24 by way ofthe load-resistor i1 and condenser Ila. The delay network 24 comprises a two-terminal filter network and, with the value of the terminating resistor" properlyadiusted, for example, to an extremely high value so that its remote terminals are open-circuited, the wave impressed on its input circuit is. translated to the remote terminals and then reflected, back, with its original polarity, to theinput terminals 25 where it appears as illustrated by curve C of Fig. 2. The reversal in polarity of wave C with respect tothe wave A is due to the tube 13, the time delay indicated at D being effected by the network. The time delay in the passage of the signal from its input terminals 25 to its remote end need be but one-half of the desired tlmedelay, since the signal is also delayed in its reflected passage back to the input terminals. Hence, only one-half of the physical apparatus which would ordinarily be required to obtain the desired delay is utilized by the system c! the present invention. The resistor 23 terminates the filter in its image impedance, so that there isno further reflection of the echo orreflected wave. The reflected waveof the network 24 is impressed upon the input electrodes ofthe tube l8 and .is repeated in the output circuit of this tube and a voltage representing the delayed signal appears across the load circuit elements 2|, 22 free from the undelayed signal which is suppressed in this load circuit as described above. By adjustment of the terminatingresistor 33 so that its value is approximately zero, the filter is effectively short-circuited at its remote end and, under this condition, the reflected wave is of opposite polarity to that of the wave impressed on its input terminals. At an intermediate value or the resistor 33 corresponding to the image impedance of the fllter, there is no reflection 5 from the remote end, that is to say, the amplitude of the reflected wave is then zero. Adjustment of the resistor 33 thus affords a convenient conmi ofiboth the amplitude and polarity of the refleotedi delayed wave which is translated by 10 the system,

While there has been described what is at present considered to be the preferred embodiment of this invention, it will be obvious to those skilled in the art that various changes and modil5 ficatlons may be made therein without departing from the invention. and it is, therefore, aimed in the appended claims to cover all such changes and modifications ,as fall within the true spirit and scope of the invention. 20

What is claimed is 1.,A wave-signal translating system comprising an input circuit adapted to have a wave signal impressed thereon, a reflecting delay network coupled to said input-circuit, an output circuit 25 coupled to said n'etwork, for translating said delayed signal, and additional means coupling said input and outputcircui'ts tor neutralizing the undelayed signal in said output circuit.

2,.A wave-signal translating system compris- 30 ing an input circuit adapted to have a wave signal impressed thereon, a reflecting delay network having input terminals coupled to said input circuitQan output circuit coupled to said terminals for translating said delayed signal, and ad- 35 ditional means coupling said input and output circuits for neutralizing the 'undelayed signal in said output circuit. 1

3. A wave-signal translating system comprising an input circuit adapted to have a wave 813- O nal impressed thereon, a, reflecting delay network having input terminals coupled to said input circuit, an output circuit coupled to said terminals for translating the delayed signal and incidentally translating the undelayed signal, and additional means coupling saidinput and output circuits for translating said undelayed signal therebetween with a polarity opposite to said incidentally translated undelayed signal, whereby said undelayed signal is substantially suppressed 50 translating channel coupling said input and output circuits for translating said signal to said output circuit with equal amplitude and opposite polarity, whereby the undelayed signal is substantially suppressed in said output circuit. and a reflecting delay network having input terminals coupled to one of said channels and adapted to reflect said signal with a predeterminedtime de- 05 lay. i

5. A wave-signal translating system comprising an input circuit adapted to have a wave impressed thereon, an output circuit, a first signaltranslating channel coupling said input and out- 7 put circuits and including an odd number of vacuum-tube repeaters for translating said signal to said output circuit with one polarity, a second signal-translating channel coupling said input and output circuits and including an even numl5 ber of vacuum-tube repeaters for translating said signal to said output circuit with equal ampli tude and opposite polarity, whereby the undelayed signal is substantially suppressed in said output circuit, and a reflecting delay network having input terminals coupled to one of said channels and adapted to reflect said signal with a predetermined time delay.

6. A wave-signal translating system comprising an input circuit adapted to have a wave signal'impressed thereon, a reflecting delay network having input terminals coupled to said input circuit, an output circuit coupled to said terminals for translating said delayed signal, additional means coupling said input and output circuits for neutralizing the undelayed signal in said output circuit, and means for adjusting said network to control the amplitude of the delayed translated signal.

- 7. A wave-signal translating system comprising an input circuit adaptedto have a wave signal impressed thereon, a reflecting delay network having input terminals coupled to said input circuit, an output circuit coupled to said terminals for translating said delayed signal, additional means coupling said input and output circuits for neutralizing the undelayed signal in said output circuit, and means for adjusting said network to control the amplitude and polarity of the delayed translated signal.

8. A wave-signal translating system comprising an input circuit adapted to have a wave impressed thereon, a dead-end filter network having input terminals coupled to said input circuit and adapted to reflect said signal with a predetermined time delay, an output circuit coupled to said terminals for translating the delayed signal,

and means connected between said input and output circuits for neutralizing thevundelayed signal in said output circuit.

9. A wave-signal translating system comprising an input circuit adapted to have a wave impressed thereon, a dead-end filter network having its input terminals coupled to said input circuit and adapted to reflect said signal with a predetermined time delay, said network including an adjustable terminating impedance at its remote end, an output circuit coupled to said network for translating the delayed signal, means connected between said input and output circuits for neutralizing the undelayed signal in said output circuit, whereby adjustment of said impedance is efiective to vary the amplitude and polarity oi the translated delayed signal.

10. A wave-signal translating system comprising an input circuit adapted to have a wave impressed thereon, an output circuit, a first signaltranslating channel coupling said input and output circuits for translating said signal to said'output circuit with one polarity, a second signaltranslating channel for translating said signal to said output circuit with an opposite polarity,

whereby the undelayed signal is substantially suppressed in said output circuit, and a dead-end filter network including an adjustable terminat ing impedance at its remote end and having input terminals coupled to one of said channels for reflecting said signal with a predetermined time delay, whereby adjustment of said impedance is efiective to vary the amplitude and polarityof the translated delayed signal.

- HAROLD M. LEWIS.