US1855569A - High speed telegraph transmitter - Google Patents

Description

April 26, 1932. H. CHIREIX HIGH SPEED TELEGRAPH TRANSMITTER Filed June 30, 1927 E w M sum 5 khxhQNk ii: M 5 H T i n; 5255 h5w ki mi uw-wwkk law n. w v QWHUW ,ooooooooo.oooooooooooo.ooooo oooooooooooooooooooood N 0 O mum O v v INVENTOR HENRI tHlRElx A ORNEY Patented Apr. 26, i932 u 'ran status jPfATEMT- LQFEEQE HENRI 'dirmnrx,or

V mem'srnnn rn nnenarn Application fllecl June 30, 1927, Serial No. 202,484, mid inFrance J'uly 9', 1926.

. The object of the present invention isto provide means whereby a line current may be sent according to the rhythm of Morse-code signals, for instance, at an extremely rapid rate, at all events, more rapidly than has been possible by mechanical systems involvingfinertia in relays, etc. i

Systems known in the prior art consist in the use of a perforated strip or band allow-- 10 ing of the passage at intervals'of a beam of light caused to impinge upon a photo-electriccell. Systems of this kind involve the drawback that they require a whole set of optical devices, a photo-electric cell and an amplifier folri amplifying the currents produced by the ce Now, the system forming the sub'ect-matter of the present invention consists: asically is active; The dielectric may consist of air or of a material possessing a dielectric constant higher than air. The result is a varia-- tion in capacity and consequently a variation in the ensuin frequency. To carry this method into e ect as will be understood, it is necessary that the frequencies of the said small oscillators should be very high in such a way that the action under consideration 40 may result in a variation in beat frequency chosen in the following way: When a solid portion of the band (solid dielectric) is placedopposite the electrodes of the small auxiliary condenser, the beat frequency is vmade very low, while when the perforated band presents a hole opposite the electrodes of the small auxiliar condenser, then the beat frequency is 'shi ed into the range of musicahnotes. This frequency is then modof several hundred periods. According to a. preferable plan, arrangements may then becrately' amplified by the aid. of trans formers. provided with a limited number of turns sdthat the grave-note periods may not rent is detected. Hence, it will be seen that our cut is available at the output end of the ampifier only in the presence of one or two be transmitted, and then, if. desired, the cur- By paying out the-perforated.

A better understandingof the invention willbe had from'the following detailed description and therefrom when read in connection with the drawings-in which,

Figure 1 shows a perforated tape be used to vary the capacii; of the condenser in 'one of the oscillation generators,

Figure 2 shows a modification of the perforated tape shown in Figure 1 Figure 3 shows a circuit arrangement including the oscillation generators and the amplifiers, h

Fi ure 4- shows the relation between the v'aria le frequency oscillation generator and thle frequency controllingperfiorated tape, w ile,

Figure 4a shows a modification of the condenser arrangement of Figure 45.

fora'tions of the band may be arranged and chosen irgggdifierent ways. For instance, it is practicalfy recommendable to use for the Morse code, and in combination with existent perforators, a band of the kind shown in Figure 1.

Referrin to 1 re 1, 1 stands for the forward-feed 0168?; the tape; 2, the perforations indicating dots; and 3, the perforations indicatingdashes. 4c and 5 finally. indicate the projections of one of the electrodes of two small auxiliary condensers connected in passage ofa dot such as 2, though the varia- 4 u, so The plates ofhe condenser and the pera bridge circuit input which would be adtape.

tion in capacity remains the same regardless of whether dashes or dots are dealt with.

As shown in Figure 2, it is also possible to use a special tape directly perforated in Morse signals, the dashes 3' corresponding to a longer perforation than the dots 2. 1 indicates again the tape feed holes, while 4' shows a projection of an armature of an auxiliary condenser.

Figure 3 shows a circuit arrangement which ma be used to carry out my invention. Tu e10 produces oscillations of a fixed frequency F. Tube 12 produces oscillations of a frequency H which depends upon the capacity amount of C.-- The capacity of C in turn depends upon the perforations of the Both F and are Very high frequency so that the slight variation in C will produce a considerable percentage variation in the difference between H and F. This difference HF need not necessarily be audible.

i The only requirement is that when an unperforated part of the tape is passing, the difference I-I-F should be sufficiently out of tune with the, amplifier so that nothing happens, but when a perforation passes, the difference H-F should be that to which the amplifier is tuned. Tube'13 is the tube which produces the difference frequency and I have shown vantageous in practice as it prevents the oscillators 10 and 12 from influencing each others frequency. The resistance capacity 16 and applied to the grid of tube 17 which,

combination Z is the element required to balance the bridge and its value is determined by the grid filament impedance of the tube. Oscillator 10 is coupled to circuit F of tube 13 while oscillator 12 iscoupled to circuit H. The beat frequency HF is selected by the tuned circuit in the plate of tube 13 and amplified by tube 14 and detected by tube 15. As each dot in the tape passes the condenser there will be an increase of current through the resistance in the plate circuit of detector 15.

The pulses of .voltage are amplified by tube acts as the modulator tube of a Heising system of modulation of which tube -18 is the oscillator which is adjusted to a frequency S which is the frequency at which the radio transmission is to be efiected. The oscillator 18 is then coupled to the input of a two stage amplifier which vfeeds the antenna. This amplifier shown for convenience at the bottom of Figure 3 includes an inductance S couled to the oscillator 18 and included in the i 3' "input circuit of an amplifier 19 the output circuit of which is in turn coupled to an yes.

inductance 21in the input circuit of a second amplifier'20. The second amplifier 20 is coupled by means of an inductance 22 in its out-' circuit to the load circuit which for purposes of illustration has been shown to be a radiating circuit.

Figure '4 show'sgin detail a variable freby a main capacity and a capacity C which is variable in accordance 'with the present invention by changing the dielectric between the plates 4, 4 thereof. As pointed out above, the capacity of the condenser C is altered in the invention by altering the dielectric between the plates 4, 4. This is accomplished by passing the perforated tape between the condenser plates. Since the dielectric constant of air is different than the dielectric constant of the material of which the tape is composed, the capacity of the condenser C will be varied as the dielectric thereof is composed alternately of air and of the material between the perforations in the tape. In Figure 4, the tape has been shown to be similar to the tape illustrated in Figure 2.

In case the tape shown in Figure 1 is used to control the frequency of the variable frequency generator 12, a condenser arrangement as illustrated in Figure 4a is used. As will be seen in Figure 4a, the condenser C comprises plates 4, 5 cooperating with ure 1 to control the frequency of the oscillation generator 12.

It will be understood that the invention is capable of a great number of modifications,

' plates 4, 5' and with the tape shown in Fighaving coupled input and output circuits, a

second thermionic oscillation generator having coupled input and output circuits, means in the, piput circuit of said last named oscillation-generator to tune said last named oscillation generator to a frequency differing from the frequency of the oscillations generated by said first named oscillation generator, an auxiliary capacity connected in parallel with said tuning means, means for varying the dielectric between the electrodes of said auxiliary capacity in accordance with the signal to be transmitted, and a utilizing circuit connected toboth of said oscillation generators.

2. In radio communication apparatus, a source of oscillations of constant frequency, means for producing oscillations at a frequency differing from the frequency of said frequency amplifier connected with said combining circuit, signal translating means connected with said beat frequency amplifier, means for modulating the oscillations produced by said thermionic oscillation generator comprisinlgan auxiliary capacity connected in para 1' with 'said tuning capacity and means for varying the dielectric of and auxiliary capacity at slgnal frequency.

3. A telegra h, --transmitter including a thermionic osci lation generator having coupled input and output circuits, a sec on there mionic oscillation generator having coupled input and output circuits, capacity means in I m the input circuit of said last named oscilla tion generator-to tune said l ast named oscillation generator to a frequency difiering from the frequency of the'oscillations generated by said first named oscillation generator,'a n auxiliary capacity connected in vparallel with said first named capacit means for varying the dielectric between the electrodes of said auxiliary capacity 'in accordance with the signal to be transmitted, a thermionic relay having its input circuit coupled to bothiof said generators and its output circuit coupled to a selective amplifier tuned to the beat frequency, and a transmitten connected ,with said amplifier. r

4. In radio communication apparatus, a

source of oscillations of constant frequency, thermionic means for producing oscillations at a frequency difiering from the frequency of said first named source compiising a thermionic tube having coupled input and output circuits, capacity means fortuning said input circuit, a combining circuit connected with both of said oscillation generators, a beat frequency amplifier connected with said combining circuit, signal translating means connected with said beat frequency amplifier, an OS.- cillator connected with said signal translating means, a work circuit connected with said 7 oscillator, means for modulating the oscilla- 4o tions produced by said thermionic oscillation generator comprising an auxiliary capacity connected in parallel with said tuning capacity, and means for varying the dielectric of said auxiliary capacity at signal frequency.

HENRI CHIREIX.

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