US1919888A - Multiple signaling system - Google Patents

Description

July 25, 1933- c. w. HouGH MULTIPLE SIGNALING SYSTEM 3 Sheets-Sheet l Filed Dec. 27, 1930 July 25, 1933. C;l w A HQUGH 1,919,888

MULTIPLE S IGNALING SYSTEM Filed Dec. 27, 1930 :5 Sheets-sheet 2 INVENTOR Clin t0n, W Halli/IL.

BY WSEMY N July 25, 1933.

c. w. Houcal-l MULTIPLE SIGNALING SYSTEM 3 Sheets-Sheet 3 Filed Deo. 27, 1930 IT .mhls o WM nu 'Hf Il .mhngvwo INVENTOR l i12 fon W Hough.

c 'Mu-A4 g ATTORNEY siste in providing u multiple signaling sys- 1 1 nuiltiple sign sling Patented `July 25, 191313` y CLINTON WALLACE 11011111101 11111.11 Yon-K, N. Y., iissIGfNoR 111017111111111 111111310, 111e.,

OF NEW YORJQN. HY., A CORPURATXON OF DELAWARE i Y MULTIPLE 116111111111116 SYSTEM Appiieliiimi 1111111 December 27, 1930. serial No. 505,055.

"My invention 'pertains in general to signaling systciuis Vand vspecifieelly relates to si guiding systems` tor siniultiineously `transinitting' 11nd receiving-1:1 'plurality otf111essages or prog-rains.` v ,y 1 1 One oftlie 'objects of niy invention con* terri in wliicli'nieiiiis'are-,provided1to1.' simultaneously trzuisinitting end reeel *111g `inoi'e than one niessugie or progriuil by.c11rr1er 1l-iiiotber object Iconsists inproducing` a. systeurfor the sin'iultzuieous *t1i111s1111ss1o11 `end reception of inoiethan one program by `carrier frequency current etonerlrequency `produced by tlie interruption "of irradiaa tions incident upon pliotosensitive ineens.

A i'urtl'ier object coiiiprises producing 11- stem in' which signal ii'iodulzition occu before liigglifrequency oscillation 'gen(1111151.11011 y l` accomplish `tlie above desirable obgec'l's 5 in 11 novel. signaling system employing liglit triiiisinitter 11nd receiver;

interrupting uien interrupting 11111111191 ior trzuisniitting and rel` eeiviilg'fi plui'zilii'y olE` programs or messages `bythe .multiple nieduliition oi carrier tre-` queney current nt 11 single-lrequencv.

" :[11 tlie drawings Wliieli accompany 11nd forni i1 part of this specificfiition iuidin designate 'which `like re'lei'eiioe i'iuiiieiii'ls1 eorreslfionding parte tliroi "rhoutf 1 Fig. l is lingiiuniiie "respresentetion ot one embodiment oli tbe multiple signaling; sysieni oi? "my invention",showing` tlie nt eveletion'o s en'iployed 1n :ny syst-e111; y liig. 18 is `sideelevation, Vpartially sectioned, ot the" light `interi?uptingi` ineens of ling'. is 1:1- sectioiiel View of 1pl1otoelec tric .Y cell housing :ind a.. lyinipliousing ein- "ployed in tlie 111p11111'iit11s ojl lV` n 1 Fig. 15111.11 un alternative foi-.111 111i! thev 11r- 'iiiliigenient o'f 1311.124; :1nd, 1

the system of `n'iy` invention. 1.' 1,

lii'c'zil "representation of1 In `111y co-pendiiig epplicetioinseriel 1111111!` ber 469,725,"iled1 July 22,1980, patentedl November l, 1932, No. 1,886,188 and entitled High frequency,generator and iiiodulzitorf" l lieved'isclosed a system iii which the ii`1`-"`V tensities of e plurality of light beeins" iii-e variedVV in accordance with modulating cui` rents and periodically intercepted at superf audible frequencies by ineclienical ineens to produce lnioduleted multi-frequency poly pliese alternating currents. My present invention contemplates providing,` signal trans* inissioii ineens for varying the `intensities oiI zi plurality oiliglit beeins iii accordance with modulating curi-ents 11nd, sequentielly exposingl pliotosensitive devices to these light beams et super-audible frequencies to produce' liigli frequency oscillations l at e single frequency wliicli will be modulated. with several `simultaneous messages `or prof.`

1 grains. ,1 My invention` 'further eonteinpletes providingsignal reception ineens for sequentizilly exposing` other pliotosensitive de! vices to i1 source oli' ii'i-adiations'under control ot tlie aforementioned liigli frequency,`

`oscillations to atleet the selective energizetui'n ,secured to e bese Referringto Fig.. 3ei1otlier mounting ring 5 siinilariiicoiistruction to a'iid-coextensive with the inouiitf ing ring l is positioned on the bracket 7 Wliieli secured to tlie bese 3, `as shown.A

in opaque disli1 -8 interposed between the mounting ring, 1' and 5 end is secured to tlie` ernietureslieit 9 oit' a1 inojtor l-O. The inotoiY l0 is secured to `standards `11 "which ere mounted on tlie besev 3Q .Y Two lainpliousings 121 1nd` are posi tioned upontlieinountiiig ring1 l. rRefer-C ringto Fig. 4l, it will be` seentliet the leinp liousinglZ isrsecui'edlto tlie ringl bye liol-` 10117 stud l5 which extendstlirouglienennu! leislot intlie ring` l and is secured. byfenutV 16; A neonglow laiiip 17 is mounted Within alziinp housing 12.11 Connection `Wires fromV .the lamp 17 are extended through the hol- ,5 by means of a hollow stud 2O extending through an annular `slot in the ring 5 and secured by a nut 21. A photoelectric cell 22 is positioned Within the housing 19 so that the photosensitive cathode thereof is directed towards the adjacent neon lamp 17. An-

other photoelectric cell housing 23 similar to the housing 19 is mounted upon the ring 5- adjacent the lamp housing 13 and is prof vided with a photoelectric cell 24 diagrammatically illustrated in Fig. 1. pertures are provided in both the'photoelectric cell housings and in the lamp housings so that light will be directed fromthe glow lamp contained within each lamp housing to the sensitized cathode of the adjacent-,photoelectric cell. 1

The disk 8 is provided.A with an annular series of apertures 25 each of which will permit the 1 passage .of light therethrough. These apertures are spaced in a manner such that, in the rotation of thedisk 8,only one aperture` will register with either of the apertures in the housing 12 or 13. For eX- ample, in the positionof the disk 3, shown in Fig. 2, one of the anertures 25 is in register with the Vlamphousing 12 permitting light to pass to the adjacent photoelectric cell, while light from the lamp housing 13 is entirely cutoff by the disk 8, there be n no one of the apertures 25 in register therewith. Rotation of the disk will iermit light to 'C pass, alternately, from the lamp housings 12 and 13 to the adjacent photoelectric cells.

It will be evident, then, that these photoelectric cells will be sequentiallyY exposed to the light rays'emergent from tue lamp housings 12 and 13; Y

YThe motor 10 is preferably of themsynchronous type for keepin` in step with an alternating current and is adapted to rotate the disk 8 at high speeds so that the sequential excitation of the photoelectric cells opposite the lamp housings 12 and 13 will talre place at super-audible frequencies.

Fig. 1 diagrammatically represents means for the transmission and reception of multiple programs according to my invention. Referring in detail to Fig. 1', the neon glow lamp V17 is connected vthrough batt-ery 28 to the secondary of Va transformer 29. A microphone 30 is connected through battery 31 to the primary of transformer 29.

32 to` theserondary of a transformer 33,

The neon glow lamp 18 is connected through battery release battery to the primary of the transformer 33. Sound waves incident upon the microphone 30, acting through the transformer 29,y control the intensity of illumination of the lamp 17 in accordance with the sound waves. @ther sound waves incident upon the microphone 34 act through transformer 33 to similarly control the intensity of illumination of the lamp 1 8 in accordance with the sound waves. rl`he microphones 30 and 34, and their associated circuits, are representative of diilerent sources of modulating currents. According to my invention these sources of modulating currents are entirely independent of each other and may constitute two distinct program or message channels. t will he obvious that the illumination intensities of the lamps 17 and 18 could be controlled Afrom other sources of modulating currents, such as from a television scanning system, without departing from the intended scope of my invention.

'l`he' photoelectric rcells 22 and 24 are connected to amplifiers 36 and 37. The amplifiers 36 and 37 may be any suitable type of conventional amplifier well'known in the art. 1n the present embodiment of my invention l employ a multi-stage resistance coupled thermionic ampliier. r1`he output from amplifier 36 is connected to an inductance 33 while the output from transformer 37 is connected to inductance 39. The inductances A33 and 3) form independent primaries of a "than those lfin@ within a band above the rate of the interceptions of the disk 8 minus the modulating frequency range and below the rate of the interceptions of the disk 8 plus the modulating frequency range. The output from 'the filter 41 is directed to a transn'iitter 42 which comprises means well known in the art for suitably increasing the energy value of high frequency signaling currents for transmission over distances. ln the present embodiment of my invention the output of the transi'i'iitter 42 is directed through capacitive couplings 43 to power lines 44. High frequency oscillations from the transmitter 42 are therefore impressed, as carrier current, upon the lines 44. The lines 44 are connected at the terminals 45 to a source of commercial alternating current.

Accordingto my invention, I provide neon glow lamps 47 and 48, disl 49, photoelectric cells 50 and 5l, and motor 52, which are similar to the neon glow lamps 17 and 18. the disk 8, the photoelectric cells 22 and 24, and the motor 10. These elements are arranged in a mechanical construction similar v15o that :Shawn in rigse, amid 4.1 A highA frequency `tuner and amplifier is provided Leiaess y ,i reception of high frequency signals substantially within the frequency rangeftransmitted by the filter 41 and, also, av multi- `stage amplifying Vsystem for the amplifica@ y tion of thesesignals. lilhe input to the tuner y 53 is vconnected through capacitive couplings l 54 'to` the, power `lines-44 for the reception of carrier frequency energy from `the trans-f g `spectivelyconnected to amplifiers 55 and 56.

i The amplifiers `55 and 56 aresimilar in lcon-` struction to ampliers 36` and 37; VThe out-V put `of the amplifiers 55 and 56 are directed f tothe demodulation device 57 and theV de- . inodulation device 58,1 respectively. "The de-V modulation devices 57and 58 eaclicomprise "a vacuum tube-detector systeniwell known initheart for demodul'ation of the'modulated high frequency energy.` rlhe output of the.demodulation devices 57 and 5,8 is

` vdirected to two :loud speakers 159 land 60, re-

former 65, the primary of which isffconnect-` spectively, which comprise :means for translatingelectrical signaling energy into'equivaient acoustical enelgyi Fig. 5 representsan alternativemethod of In this arrangement two neonlamps 61 and q G2 are positionedwithin,an'elongated lamp` housing 68.4 The neon lamp 611s connected throughbattery @4to the secondary of transed througha battery toimicrophone 67.

The neon lamp`62 is connected to batteryl`68 and is maintained lat "a steady `illumination A intensity.` The intensity` of illumination* `preduced by, thelampl is varied in acy. system for the effective )transmission and, `reception of simultaneous programs, Ormesj sages,is asfollows:`

cordaneefwithl modulating currents y under C control of fthe microphone 67. Thephotoelectric cell 22is, therefore, Vunder.` control ofthe additive .intensities of the -twolamps (i1 land .62. Theintensity yof the lamp 62" servestolbias the operation ofthe 'photo' electric cell 22M Such an arrangement for modulationv may befveryfdesirablefor someY purposes, such ,as `when it is'desired to modulate upon a higher {part "of the character-` isticA curve of .the photoelectric ,cells i The operation `of mymultiple signaling Sound lwaves, comprising a program or `message, impinging upon the microphone `d0 fact through 'the `transformer `29` to controll "i theintensity? ofthe "illuminationi ofthe lamp At the same time, other sound waves comprising: a different program or message and :impingmg upon the microphone 34fact through thetransformer 33 'tocontrol the intensity'of theillumination of the lamp 18. 'The motorlO is madetorrotate the disk 8 at ya constant high speed wherebythephotof h .electric cells 22 and-24 are alternately, orV

sequentially, exposedtothe lamps 17 and 18,

respectively", q at Asuper-audibleI i frequencies,V

Each of the photoelectric cells 22 and 24 will then `receive a. series of light impulses, :the illumination intensityV as before explained.

Y inductances 38 and789 alternately act to induce, inhthe` inductance.40,` electromotive forces `corresponding to the sequence of modulatedimpulses from the two amplifiers 86.and87.p'l`he-filter 41 substantially at-` tenuates all frequencies other` than those desired and eliminates `harmonics and other objectionable extraneous` frequency effects. The transmitter42 increases the energy `value.` offtheoutput from thefilter 41 for transmission,through 'the l capacitive couplings ,43,v over the power lines 44. Y modulating illumination intensity which" differs frontthatshown in-Fig.` 1" inV thata l source `of biasing illumination isprovided in addition'to the modulatedv light source. f

` The transmitted high frequency currents are directed `from the capacitive `coupling cillations which are `received and amplified by the highV frequency'tuner andamplifier 53@ .'llhemotor 52,7{being connected through `:thepowerf1inesj44 to the same source `of *alternating current which supplies the ,i

motorlO, will rotate the disk 49 at sub..

stantiallyi the same speed as the disk It`V will,v Vof course, be `understood that` the motors 10 and 52 are inotnecessarily conl nectedito the same source of .current supply but maylbeconnec'ted to independentsources Y of currentlsupply and synchronized byother i means Vwell known in the art.`

exposes the photoelectric cells"50 and 5.1 to

the effects ofirradiations from the lamps 47 The disk 49,rotating ata highspeedin y and 48,4 respectively;` .Thelamps 47 and 48, Y being connected ,in series withthe .output of tl1e`7high frequency" tuner and amplifier 53,

`have substantially equal illumination intensities at all times. However, `1 the `disk 49 sequentially `exposes the photoelectric cells 50 and lfto the lamps 47 and 48 so that the intensityof the `light impulses incident upon. vthe ,photoelectric .cells 50 and 51 will respectively correspond 1 to fthe, intensity of the kas light impulses incident upon the photoelectric cells 22 and 24. These highl frequency light impluses willV produce photoelectric currents in the photoelectric cells'() and 5lv which, when respectively amplifiedby the amplifiers 55 and 56, and respectively detected by the deinodulation devices 5,7 and 58, will cause the loud speakers 59 and 6() to reproduce, in efli'ect, the sound waves respectively incident upon the microphones 30 and 34.A Y

In Fig. 6, curve graphicallyrepre sents, for a'given time interval,xthe amplitude of the modulating current 'Linder control of the microphone 30 forY typical acous tical conditions during a program. The curve Bis a graphical representation, for the same time intervahof the amplitude of the modulating current under? controlof the microphone 34 for typical vacousticalconditions of a different program. VThe curves- A71 and A2 graphic-ally represent the theoretical upper and lower` side bands transmitted by the high frequency carrier current produced according to my system under control of the modulating current ,A, while the curves B1 and B2 represent the theoretical upper and lower side bandstransmitted by the high frequency carrier current produced according to my system underconi trol of the modulating. current Bz The frequency of the carrier current is Ysufficiently highso that the time intervals `between the high frequency wave peaks for a particular side band, such as the difference between f2 and 151 for sideV bande, are considerably` 'less than any frequency audible to the human ear. For example, the carrier frequency used in the present embodiment of `my system could be of the order of 30,000

cycles per second` which wouldmake the time interval between t2 andV t1 equalto one.fifteenth-thousandth Vof asecond. t 'lhe effective frequency ofthe carrier foreach modulating' current is fifteen kilocycles, while thefactual frequency of the carrier current isrthirty kilocycles.` However, the actual Y frequency band necessary for the transmission of both the modulating currents A and Bn-is'equal to the frequency of thercarrier current plus' twice the fre quency rangeA Within vwhich the modulation occurs. "lhat is, the actual frequencyvrange required according to my system is substantially the saine as ifbut one-modulating current, comprising the upper and lower side bands, wasbeing transmitted bythe single carrier frequency, v lt will be obvious that, cy using higher frequencies foi-'the carrier current, more than two programs can be, in effect, simultaneously transmitted and j received according to 'my'inventiou It is, therefore, to be understood that the present embodiment of my invention, showing means fortransmitting and receiving two programs, is'k purely arbitrary and that the number 4of transmitted and received programs canbe increasedif desired. 1t will also be obvious that the aperture disks used in ymy system may be arranged so that several light impulses in succession are given to each `photoelectric. cell `so that several wave `peaks in succession are modulated by one modulating current and then another group of wave peaks are'inodulated by a different modulating current.

lt will now be apparent that I have provided a novel signaling system for the transmission and reception of multiple messages or programs which offers many advantages in its use, principal among which is conservation of frequencie. Although l have shown a preferred Vembodiment of my multiple signaling system itis, of course, conte1nplated that changes therein will readily occur to those skilled in the art lbut which will not depart from the intended scope of my invention. l do not, therefore, desire to limitinyself yto the foregoing except insofar as may be pointed. out in the appended claims. l

'lllfhat l claim as new 'and original and desire to secure by Letters Patent of the United States is:

l, 'multiple signaling system comprising, a plurality of sources of modulating current, a group of different sources of irradiations cach of which composed of a plurality of sources one of which is under control of one of said sources of modulating current, pliotosensitive means, means for sequentially exposing said photosensitive means to said group of plural sources of irradiatious at super-audible frequencies, other; means for producing irradiations under control of said photosensitive means, a plurality of photosensitive devices all of which are commonly under control of said last mentioned irradistions, means for sequentiallyexposingsaid last mentioned photosensitive devicesto said irradiations, and a vplurality of translating devices each of which is under control ofone of said last mentioned photosensitive devices.

2A multiple signaling system comprising, a plurality of sources of modulating current, a pluralityv of sources of light cach of which consists of apair of sources one of which is underccntrol of' one of said soul of modulatingcurrent,.a group of photoelectric cells, a disk'interposed. between said sources light andsaid photoelectric cells and .having apertures for sequentially eX- posing said photoelectric cells to said pairs ofl sources of light, means for rotating said disk, means vfor producing irradiations underv control of said photoelcctric cells, another group of pho'toelectric cells, a second disk having apertures for sequentially eX- posing saidv last mentioned photoelectric `cells to said irradiations',` and a `plurality ,of

electric cells.

translating devices each of Which isunder control of one of said last'ineiitioned photo- 3. A multiple signalingsysteni compris-` ing, a plurality of microphones, a plurality `of sourceso'f light eachjof` which consists `of a pair of sourcesv one of which ls'under n control of one of said microphones, photosensitive means, means for sequentially eX- posmg said photosensitive means to said pairs of sources of light at super-audible frequencies, means for producing irradiations under control oi said photosensitive Vmeans, a plurality oiphotoelectric cells, a

CLINTON VALLACE HOGH. y

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