US884986A - Wireless telegraphy. - Google Patents

Description

PATENTED APR. 14, 1908.

MARGONI. WIRELESS TBLBGRAPHY.

APPLICATION FILED NOV. 28,-1902.

TIME.

' UNITED STATJELQEZXEENT oFFIo-EQ,

GUGLIELMO MARCONI, OF LONDON, ENGLAND, ASSIGNOR TO MARCONI WIRELESS TELE-g GRAPH COMPANY OF AMERICA, A CORPORATION OF NEW JERSEY.

- WIRELESS TELE GRAPHY.

Specification of Letters Patent.

Patented April 14, 1908.

Application filed November 28, 1902. Serial No. 132,974.

To all when: it may concern:

Be it known that I, Guounm o .\[.-\ReoNI, a sub ect of the King of Italy, resid\ng at in Finch Lane, in the city of London, England,

electrician, haveinventcd certain new and useful Wireless lelegraphy, ol which the following is a s 'mcilication.

This invention is based upon the discovery that a' core or rod of magnetic material which is not sensibl all'ected by high t'requcncy elm-trical oscillations or l'lertzian waves under ordinary circumstances, becomes sensitive to them when placed in a varying or moving magnetic tield.

My present theoryof the action of the apparatus hereinafter described is as follows, although I intend to claim this ap -iaratus broadly, whether this theory is correct or not:lt is a well known fact that after any change has taken place in the magnetic force acting on a piece of iron, sometime elapses before the corresponding change in the magnetic state of the iron is completed.- if the applied magnetic force be eithersubjected to a gradual increase followed by an equally gradual diminution or caused to etl'ect a cyclic variation, the corresponding induced magnetic variation in the iron will lag behind the changes in the applied force, To this tendency to lag behind, lrot'. Ewing has given the name magnetic hysteresis. It has been shown also by (ierosa, l inzi, and others that the effect of alternating currents or high frequency electrical oscillations acting upon ifim, is to reduce considerably the ell'e'c'ts of magnetic hysteresis, causing the metal to respond much-more readily to any influence which tends to alter its'magnetic condition. The ell'ect of electrical oscillations probably is to bring about a momentary release of the molecules of iron from the constraint (or .viscosity) in which, they are ordinarily held,

diminishing 'theirretentiveness and consequently decreasing the lagin the magnetic variation taking p ace inthe iron. I, therefore, anticipated'that the group of electric waves emitted by each spark of a llertzian radiator would, i caused to act upon a piece of iron which is being subjected at the same time to the slowly varying magnetic force, produce sudden variation, in its magnetic hysteresis, which variations would produce others of a sudden or jerkyinature in its magnetic condition. in other words, the

magnetization of the iron, instead of slowly Following the variations of the magnetic force applied, would ateach spark of the transmitter suddenly diminish its magnetic la-g caused by hysteresis. 'lhese, jerks in the magnetic condition of the iron would cause induced currents in a coil of wire of strength sul'licicnt to allow the signals transmitted to be detected intelligibly on a telephone, or perhaps even read on a galvanolneter. Thejerks in the magnetic condition of the iron might also be detected by a telephone diaphragm applied directly thereto. 7 I

()n a core consisting of some magnetic material which may be iron, preferably ina subdivided state, such as line wires or needles, is wound one or several layers of insulated coper wire. Over this winding is placed insuating material and over this a secondary winding of thin copper wire contained ina narrow bobbin. The ends of the winding nearestto the iron core are connected one to earth or to a capacity and the other to an elevated conductor, or they may be connected to the secondary of a suitable trans- .former or intensifying coil. The ends of the secondary winding are connected to the terminals of a telephone or other suitable receiving instrument. The secondary winding may, however, be omitted and the magnetic changes in the iron core detected by placing the telephone diaphragm in innnediate proximity to the said core or by any other suitable means. At the ends of the cor. or in close proximity to it is Jilaccd a magnet which is so moved or revol ved as to cause a constant change or successive reversals in the magnetization of the iron core.

It is found that if the. electrical oscillations of suitable periodare sent from the transmit ting station according to the now well known methods, rapid changes are etl'ectod in the.

magnetization of the iron core, which changes produce induced currents on the winding, and these currents in their turn reproduce on the telephone or receiving instrument the intelligible signals sent from the transmitting station. Another successful method is to keep the magnet fixed and use an endless iron rope or core of thin wires revolving on pulleys through the windings (which in this case are separated from the iron by means of a thin glass tube to prevent chafing of the wires) in proximity to a magnet or magnets.

'Figures 1 and 2-are diagrammatic front and side elevations of the arrangement.

I to a ca acity Ewhich may be the earth, and.

varying magnctic field in sai the ot ierto the aerial conductor A. The

wire ofthe secondary winding 0 isabout .02

cm. in diameter and a sufi'icient number of. turns of it is used to give a resistance about equal to that ofthe telephone T to which its ends are connected, d is a horseshoe magnet driven round by a clockwork mechanism at a spec of about one revolution per second or other suitable s eed; Figs. 3 and; show the'arrangement where a continuous band or metal rope is used. In this case two stationary horseshoe magnets d d are used which should be arranged with their like poles together. The core a isfiexible and passes around two pulleys e which areabout 10 cm. in diameter and are placed about 20 cm. apart. -/lhey are driven by clockwork at about the speed of one revolution every two seconds or other suitable speed. 9 is a glass tube on which the pri-' mary b is wound and through which the core (1 passes. The other parts are similar to those of the former arrangement. Either'iron or steel can be used for the cores or revolvin rope, but best results have been obtained wien using hard drawn iron wire or iron wire which has been considerably stretched and twisted beyond its limits of elasticity prior to being employed. 7

The telephone or receiving instrument T may be connected to the ends of the winding 6 nearest the iron and the other winding 0 be omitted, or the iron core a may be placed-in closeproximity to a telephone diaphragm and the sudden changes of magnetism in the core can then be detected by sounds produced by the diaphragm. In this case also no second winding is required on the core. The formof apparatus, as shown in Figs. 1 and 2, comprising a fixed core and movable magnet, is not herein especially claimed, but

constitutes the subject-matter of an application, Serial No. 1 141,398 filed as a division of my resent a lCittlOIl.

W hat I claiiii is: V

'1. At a receiving-station in a wireless telegraph system, the combination of a core of magnetic material, means for roducing a d core, and

means inductively affected by the core for receiving oscillations, substantially as described.

2. At a receiving-station in a wireless telegraph system, the combination of a core of magnetic matenal,;means for producing a varying magnetic field, a coil surrounding the core, and means for causing the received oscillations to pass through the coil, substantially as described.

3. Ata receiving-station in a wireless telegraph system, the combination oi a core of magnetic material, means for producing a Varying magnetic field, a coil surrounding the core, means for causing the received oscillations to pass through the coil, a receiving instrument and a secondary mil likewise surroundin the'core and having its ends connected to t 1e receiving inslrummit, substantially as described.

4.; At a receiving-station in a wireless lclcgraph system, the combination of a core of magnetic material, means for producing 11 varying magnetic field, a coil surrounding the core, an oscillation-receiving conductor connected, to one end of the coil, and a capacity 0011, su stantially as described.

5. At a receiving-station in a wireless tolegraph system, the combination of a core of magnetic material, means for producing a varying magnetic field, a coil surrounding the core, an oscillatior yrceiying conductor connected to one end flthe coil, 1 capacity connected to the other end of .fihe coil, 21 'recei'vinginstrume t and asecon coil like; wise surrounding he core and having its ends connected to the receiving instrument, substantially as described.

6. At a receiving-station in a wireless telegraph system, an oscillation-receiving conductor, a coil connected to said conductor, a core surrounded bysaid coil, and means for producing a varying magnetic iicld in the core, in combination. with a receivinginstrument, substantially as described. 7

. 7. At a recei\ *ing-station in a wireless telegraph. system, an oscillation-rccciving conductor, a coil connected to said conductor, a core surrounded by said coil, and a magnet,

and means for changing the relative positions of the core and the magnet for producing a varying magnetic held in the core, in combination with a receiving-instrument, sub stantially as described. I I

8. At a receiving-station in a wireless tclcgraph system, an oscillation-recciving conductor, a coil connected to said conductor, a core surrounded by said coil, a niagimt, and means for moving the core through the hold of said magnet, for producing a varying magnetic field in the core, in combination with a receiving-instrument, substantially as described. I

9. At a receiving-station in a wireless telegraph system, an oscillation-receiving conductor, a coil connected to said conductor, a wire passing through the coil and constituting a magnetic core, a magnet placed near lUH said wire, and means for moving the wire through the coil, for producing a varying magnetic field in the wire, in combination with a receiving-instrument, substantially as described.

10. 'At a receiving-station in a wireless telegraph system, an oscillation-receiving condoctor, a coil connected to said conductor, a core surrounded by said coil, means for producing a varying magnetic field in the core, and a recciviiig-instrument inductively affected by the core, substantially as described. 1 1. At a receiving-st ation in a wireless telegraph system, an o'scillation-receiv-ing condoctor, a coil connected to saidconductor, a core surrounded -by said coil, means for pro ducing a varying magnetic licld in the core, and a recciving-telcphonc provided with a diaphragminductively all'ected by the core,

' substant ially as described.

- 4112. At a receiving-station in a wireless tel egraph system, aniiscillation-receiving conductor, a magiietizable core constituting the armature oi a magnetic 'lield, connections whereby oscillationsreceived by the receiving conductor affect the core, and means, operating independently of received oscillations, l'or varying the magnetic 'l'ield al'oresaid. ubstantially as described.

13. .At a 'receiving-station in a wireless'teh cgi aph systni,'an oscillation-rcceiving conductor, a magnetizable core constituting the armature of a iii-agnet-ic iield, connections whereby oscillations received by the receiving conductor affect the core, means, operating independently of received oscillations, for varying the magnetic. field aforesaid, and means, controlled'by the core, for making received signals manifest, substantially as de- 40 scribed. i I

ll. At a receiving-station in awireless telegraph system, an oscillration-receiving conductor, a permanent magnet, a magnetizable core placed'within the iield of said mag- 'llti, connections whereby oscillations re.-

ccived by the receiving conductor affect the core, and means, operating independently of. received oscillations, for varying the magnetic field aforesaid, substantially as described. 15. At a receiving-station in egi'aph system, an oscillation-receiving conductor, a magnetizable core constituting the armature of a magnetic field, connections 5'5 whereby oscillations received by the receiving conductor affect the core, and a motor and means operated thereby for causing variations of tlie'inagnetic field aforesaid, substantially as described.

egraph system, the combination of an oscillation-receiving conductor, a coil connected to said conductor, means for producing a magnetic field which includes said coil, and a a wireless tel- ]6. At a receiving-station in a wireless tel by said iield,

lation-recewing conductor, a. coil connected to said conductor, means for producing a magnetic held which includes said coil, and a receiving-instruinent inductively all'ected by said field, substantially as tl(-S(I'll)(*ll.

lb. At a receiving-station in a wireless telegraph system, the combination ol-an oscillation-receiving conductor, a coil connected to said conductor, means l'or producing a varying magnetic held, and a receiving instrument ail'ected by said varying lield, substantially as described.

It). At a receiving-station in a \\'ii'elcss telegraph system, an oscillation-receiving conductor, a coil connected to said conductor, a magnet l'orcreating a magnetic iield which includes the coil, and means for varying the magnetic 'lield, substani ially as described.

20. A receiver for electro-magiietic waves, having in combination, a core of magnetic material, means for maintaining the magnet-.

ization in the core, in a constantly varying state, means forutilizing'currents produced by electro-magnetic waves for abru tly altering such magnetization, and an indicating mechanism operative by such abrupt'changes in magnetization, substantially asset forth.

.21. A receiver for electro-magnetic waves, having in combination, a core of magnetic material, means for maintaining the magnet ization in the core in a constantly varying state, and an indicating mechanism operative by abrupt changes in the amount ofthe magnetization produced by currents generated by electro-magnetic waves, tially as set forth.

22. At a receivingsstation in awireless t-ele graph system, an oscillation-receiving conductor,,a wave-responsive device electrically connected therewith, gized independently of the receipt of oscillations, for creating a magnetic field which includes the wave-responsive device, substantially as described.

substan and a magnet, ener-v 23. At a receiving-station in a wireless telegraph system, an oscillation-receiving conductor, a wave-responsivedevice electrically connected therewith, gized independently of thereceipt ot' oscillations, for creating a varying magnetic field Which'includes the wave-responsive device, substantially as described, 24. At a receiving-station in a wireless telegraph system, doctor, a wave-responsive device electrically connected therewith, and means for constantly maintaining a magnetic iield which includes the wave-responsive device.

25. In a receiver for wireless telegrapliy, a magnet for creating a magnetic field, a magand a magnet, ener-' an oscillation-receiving connet is varied.

netizable member located in said magnetic field, means for moving the 'magnetizable member with relation to the magnet for producing varying magnetism in the said member.

26. In a receiver for wireless telegraph a magnet for creating a ma netic field, 'a magnetizable member located field in proximity to the poles of said magnet and means for rotating the magnctizable member with. relation to the poles of said magnet to Vary its magnetism.

27. In a receiver for wireless telegraphyga stationary magnet and a movable magnetitable member located in the field created by said magnet, whereby uponi movement o fllie same the magnetic field produced by the mag- 28. In a receiver for Wireless telegraphy a magnet, a movable in agnetizable member located in themagnetic field created by the said magnet, and means for creating changes of magnetism in themovable member; substantially as described.

29. l n a receiver for Wireless telegraphy, a

in said magneticmeans for creatin r seaoee stationary magnet a magnetizable member located in the field created by said magnet, alternations or reversals of magnetism in t c movable member, sub stantially as described.

30. At a receivin station in a wireless transmission systen'i, the combination of means for producing varying magnetism in a magnetic body subjected to the action of the received oscillations, andlneans for detect- 1 ing the change of magnetic conditions in said body caused by the received oscillations.

31. At a receiving station in a system for signaling by electrical oscillations of high frequency. the combination of an oscill ceiving conductor, means l'or creating a magnetic field indcpendeiitlyoi the reccivml oscillations, means for varying said field by the said received oscillations and means responsive to the variations in said field for rcndcring received oscillations in telligiblc as signals.

GUGLIELMO MA'MUN-l. Witnesses:

Wirriun BLAYDES, ROBERT B. it ixsrono.

etion re-

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