US797169A

US797169A - Space telegraphy.

Info

Publication number: US797169A
Application number: US70460599A
Authority: US
Inventors: Ferdinand Braun
Original assignee: Individual
Current assignee: Individual
Priority date: 1899-02-06
Filing date: 1899-02-06
Publication date: 1905-08-15
Anticipated expiration: 1922-08-15

Description

SPAGE TELEGRAPHY.,

APPLICATION FILED IFBB. 6, 1899.

ll ltillUE.

Specification of Letters Patent.

Patented Aug. l5, 19055.

Application tiled February 6, 1899. Serial No. 704,605.

To all whom, it may] concern.-

Be it known that l, FERDINAND BRAUN, a subject of the German Emperor, and a resident of Strassburg, Alsace, German Empire, have invented a new and useful improvement in Space Telegraphy, of which the l'ollowing' is a specification.

My invention relates to the transmission ot' electric signals without connecting-wires and comprises the improvements hereinafter described.

Electrical vibrations, although similar in their physical nature, may be .classiiied Afor practical purposes into three groups. rl`he [irst group includes vibrations which are created by the relative mechanical movements oi' magnets, coils, wires and so on. rl`hese are exemplified in the well-known ordinary alternating currents, as used ior electric light and transmission oi' power. 'l`heir frequency will obviously be limited by the physical conditions of machinery.

rt second group of electrical vibrations consists oiE oscillations which are produced by the discharge of Leyden jars, or condensers, with or without inductance-coils in circuit. 'lhe frequency of these oscillations, which is considerably higher than the frequency ot the former group, can be calculated by well-known relations between capacity and inductance.

A third group of vibrations or oscillations is that iirst studied experimentally by the late Dr. Hertz, and in the production o'lE these the capacity and inductance are not obtained by means oi specially-provided Leyden jars, or condensers, and inductance-coils, but the capacity and ind uctance ot' ordinary conductors are used.

Hitherto the attention ot' inventors.l occupied with the transmission of signals without the use of connecting-wires, by means oi Hertzian or electromagnetic ether waves, has been principally confined to the use of such waves produced by the oscillations of the lastmentioned group, and one object has been to increase the frequency of these waves as much as possible. rlhis is eXempliiied by the use otl the Righi transmitter. For the transmission of such short waves it is essential, however, that the transmitting and receivingI stations should be, so to speak, visible to each other; as stated by Hertz in one oit' his earlier papers concerning the transi'nission ol.I electromagnetic ether waves and by subsequent experiments, it has been shown, that various material objects, such as sails, smoke, trees,

buildings and the like, interposed between the two stations, weaken or in some cases entirely prevent communication between them, My invention is intended to obviate this inconvenience and l do this by making' use ol electrical oscillations belongingl tothe second group above mentioned which have only a small frequency compared with the frequency of the oscillations oll the third group. By this means, owing to the greater length ol. the

. waves produced, these latter are able to pass througl'i conductors il these are but of moderate thickness. Furthermore, obstacles in the path oi" waves will not project such sharplydeiined shadows, the waves passing around them in a manner similar to that which soundwaves pass round obstacles. Another advantage in using slower vibrations o r oscillations is that their potential and amplitude, and therebjv the energy transmitted, are more easily increased. `When the higl1er-Frequency waves are used, produced by the oscillations oit the third group above mentioned, there is a certain length ol sparlr which must not be exceeded if the circuit is required to excite vibrations or oscillations; otherwise the vibrations or oscillations would be damped too much; but this means that the etiective potential is limited, which, il oscillations oi the second group are used either does not occur, or can be very easily avoided.

l have found by experiments that the oscillations produced by the discharge olE Leyden jars et usual size in a circuit having' modcrate 'inductance, are veryconvenient i'or the purpose of transmitting signals.

in carrying out my invention, l malte use oi' the well-known upwardly-projecting transmittingwire, and receiving-wire connected to the coherer in the receiving-station. lft is well understood in the art that the function oi. the YFormer wire, which projects upwardly and to a considerable height, is to spread out or radiate the electromagnetic ether waves through the air, and of the latter wire to collect these waves and to conduct them to the coherer.

As the object ol'I my invention is to use the waves created by the oscillations produced by the discharge of Leyden jars or other condensers, it is essential for my invention that the transmitting-wire be so related to the oscillation-circuit containing' the Leyden jars that oscillations will be created in the transmitting-wire by the oscillations in said circuit. Eor this purpose the transmitting-wire is in accordance with the present invention connected conductively to the oscillation-circuit, as illustrated diagrammatically in the drawings.

A form of apparatus in which the transmitting-wire is not conductively connected to the oscillation-circuit but is inductively connected thereto is described and claimed-in my application Serial No. 157,728, iiled May 18, 1903, as a division of this application.

" An oscillation-circuit comprising' a Leyden jar or condenser and spark-gap, with or without an inductance-coil, is, and for a long time has been, well known to be a persistently-oscillating circuit, or a circuit in which its electrical equilibrium having once been disturbed, vibrations or oscillations continue for a considerable length of time. In other words, this circuit is a source of maintained or sustained electrical oscillations. This circuit I have likened to a reservoir of energy,7 a portion of which is radiated from the transmitting-wire for every oscillation until there is no more energy left and the circuit ceases to vibrate.

In order that my invention may be clearly understood, I have shown in the accompanying drawings by way of example, some arrangements of circuits for transmitting signals by means of the electric oscillations above described.

Figure l illustrates diagrammatically a transmitting apparatus constructed in accordance with the invention. Fig. 2 shows a modified arrangement of the same.

In Fig. l a Leyden jar indicated at F has its inner and outer coatings connected through the spark-gap a, a coil P of small self induction or inductance being included in the oscillation-circuit which increases the normal inductance of such circuit. The inner coating is connected to the transmitting-wire M. It is well understood that the transmittingwire may be of any suitable size. The jar is charged in the usual manner by means of an influence-machine, inductorium or other suitable means.

In place of one jar, two or more can be used connected in parallel or series. Fig. 2 for example shows two jars arranged in series, or as commonly called in cascade The invention is not limited to the precise arrangements of circuits shown in the drawings, as these can be varied very considerably, and electric oscillations of low frequency suitable for transmitting signals according to my invention can be produced in various other ways.

Leyden jars have been used heretofore in connection with wireless telegraphy, but never before have the oscillation-circuits been conductively connected to the transmitting-wires so that the oscillations in said circuits create oscillations in the transmitting-wires which latter create and cause to radiate therefrom electromagnetic ether waves.

That I claim isl. In a transmitter for wireless telegraphy, the combination with an oscillation-circuit containing a condenser, of a transmitting-wire connected conductively with said circuit, substantially as and for the purpose stated.

2. Inatransmitter for wireless telegraphy, the combination with an oscillation-circuit containing a condenser and a spark-gap, of a transmittingwire connected cond uctively with said circuit, substantially as and for the purpose stated.

3. In a transmitter for wireless telegraphy, the combination with an oscillation-circuit containing a condenser and an inductance means for increasing the normal inductance of said circuit, of a transmitting-wire connected conductive] y with said circuit, substantially as and for the purpose stated.

A. Ina transmitter for wireless telegraphy, the combination with an oscillation-circuit containing a condenser and a spark-gap and an inductance means for increasing the normal inductance of said circuit, of a transmittingwire connected conductively with said circuit, substantially as and for the purpose stated.

5. In a transmitter for wireless telegraphy, a transmitting-wireprovided with a sparkgap, a condenser connected across the sparkgap, and a source of electrical energy connected to the terminals of the spark-gap.

6. In a transmitter for wireless telegraphy, a transmitting-wire provided with a sparkgap, a condenser connected across the sparkgap, and a source of periodically varying electromotive force connected to the terminals of the spark-gap.

7. In a transmitter for wireless telegraphy, a transmitting-wire provided with a sparkgap, a plurality of condensers connected across the spark-gap, and a source of periodicallyvarying electromotive force connected to the terminals of the Spark-gap.

8. In a transmitter for wireless telegraphy, a transmitting-wire connected conductively with a closed oscillation-circuit.

9. In atransmitter for wireless telegraphy, a transmitting-wire connected conductively with a persistently-oscillating circuit.

lO. In a system of wireless telegraphy, a transmittingwire -connected conductively with a source of persistent electrical oscillations.

ll. In a system of wireless telegraphy, means for radiating electromagnetic waves of low frequency, comprising a transmittingwire conductively connected with a source of persistent low-frequency electric oscillations.

In testimony whereof I have hereunto set my hand in presence of two subscribing witnesses.

FERDINAND BRAUN. iVitnesses:

FRITZ Nmss, MAX ADLER.