US1594060A - Hot-filament magnetic rectifier - Google Patents

Description

July 27 1926. 1,594,060

J. HUFF HOT FILAMENT MAGNETIC RECTIFIER Filed June 21. 1918 2 Sfiee'cs-Sheet 1 July 27,1926. 1,594,060

, J. HUFF HOT FILAMENT MAGNETIC RECTIFIER Filed June 21.1518 2 Sheets-Sheet 2 Fig.6.

V A A a n r InVentor I I Jesse Huff,

His Attorney.

Patented 1 July 27, 1926.

UNITED STATES PATENT OFFICE.

JESSE HUFF, OF NEW YORK, N. Y., ASSIGNOR TO GENERAL ELECTRIC COMPANY, OF SOEENEOTADY, NEW YORK, A CORPORATION OF NEW YORK.

HOT-FILAMENT MAGNETIC RECTIFIER.

Application filed June 21, 1918. Serial No. 241,231.

The present invention relates to that class of electrical instruments which depend for their operation upon the emission of negatively charged corpuscles or electrons from heated metals and more particularly to devices of this character which are used for the rectification of alteranting current.

It is the object of this invention to produce a device of the characteristics referred to for completely rectifying alternating current and thus make the whole output of a source of alternating current available for consumption as direct current.

The principles upon which the invention is based will be more clearly explained in the specification and the essential features more particularly'pointed out in the claims.

In the drawings which formapart of the specification Figure 1 is a diagrammatic view of an arrangement showing an embodiment of the invention in side elevation;

Figure 2 is a lan view of the arrangement shown in Figure 1;

Figure 3 is a diagrammatic view similar to Figure 1 showing certain modifications;

Figures 4: and 5 are diagrams illustrating certain physical phenomena; and

Fig. 6 illustrates a modification suitable for operation with alternating current.

As is well. known, the rectifying action of a device composed of a hot filament-cathode and a metal anode in a substantially perfeet vacuum is due to the unidirectional conductivity of the device, the current being carried only by the electrons emitted by the hot filament.

An electron in motion constitutes an element of an electric current. Such an lec tron in motion is surrounded by a circular magnetic field precisely as a conductor carrying current is surrounded by a magnetic field. Assume that in Figures 1 and 5 the dot 1 represents an electron and that in Figure 4 the direction of electronic movement is downwardly into the sheet away from the observer, while in Figure 5 this movement is toward the observer. In thefirst case the magnetic lines of force 2 surround the electron in clockwise direction, whilein the. latter case the magnetic lines 2' have a counter-clockwise direction.

If a unidirectional magnetic flux, indicated by the arrow lines, is passed in a direction perpendicular to the direction of electronic migration, it will be seen that in the first case (Figure 4:) the reaction of the two fields will result in a force acting on the electron 1 in a direction along the sheet and toward its lower edge, as indicated by the arrow 4, while in the second case (Figure 5) the resultant force will be oppositely directed. The rate at which the force will causethe electron to deviate from its original path will, of course, depend upon the relative values of the forces producing motion into the sheet and along the sheet respectively. In either case the force due to the interaction of the magnetic fields may be regulated by altering the magnetic field intensity.

In Figures 1 and 2, which are purely diagrammatic representations, 5 indicates a magnet having its poles 6 and 7 facing each other to define a distinct magnetic field of relatively great intensity. On opposite sides of the magnetic field are metallic filaments 8 and 9 which may be heated electrically by batteries 10 and 11 respectively or by small transformers as is well understood. The secondary 13 of a step up transformer 12 from which the alternating current to be rectified is derived hasone' side connected}directly to one of the filaments, say to the filament 8, and the other side through ground to the other filament. Below and above the magnetic field are placed the metallic anodes or targets 14 and 15 respectively, which are interconnected by a conductor 16 and have a common connection 17 to one terminalof a load device, the other terminal of the load device being grounded. The targets'H and 15 and the filanients 8 and 9 are inclosed in a vacumn chamber 18, indicated in dotted lines in Fig. 1. Since magnetic flux passes readily through glass, the magnet poles 6 and 7 may be placed outside the receptacle in which the vacuum is produced.

The operation ofthe device is as follows:

The hot filament 8 is charged ne atively during one alternation and the hot filament 9 during the other alternation of each cycle. An electric migration will therefore take place in turn from each of the hot filaments; to a target. As has been explained in connectionwith Figures 4 and 5, the magnetic lines intercepting the path of the electrons Cit will force the electrons coming from one of the filaments downwardly toward the target ll and the electrons coming from the other filament upwardly toward the target 15. Assuming the pole 6 to be north and the pole 7 to be south, the electrons coming from the cathode 8 will be forced toward target 14 and the electrons coming from cathode 9 will be forced up toward target 15. The thermionic current thus produced will flow alternatel from the targets ll and 15 through the common connection 17 to the load device.

The magnetic deflection of the electrons in opposite directions has the advantage that two targets may be employed whereby the heat dissipating surface is doubled. It the magnetic field is made to alternate, only a single target is necessary, since the resultant of the magnetic lines of force would have the same direction in both cases. Fig. 6 illustrates such an arrangement, the device 23 being provided with a single anode 24, and the magnet 25 being provided w th a magnetizing winding 26 to which a suitable alternating current is supplied, in this case by the conductors 27, 28.

The device shown in Figure 3 is essentially the same as that shown in Figure 1, differing therefrom only as to the mode of interconnecting the parts.

In Figure 3 the one end of the secondary 20 is connected to the filament 21 and the other end to the filament 22, while the center point of the secondary is connected to ground. While in the device of Figure 1 one filament has to be insulated against the total voltage and the total voltage is impressed on the load, in the device of Figure 3 both filaments need be insulated a ainst only one half of the total voltage an? only one half of the total voltage is impressed on the load device.

It is understood that various changes may be made within the scope of the disclosure.

I claim:

1. The combination with a source of al ternating current and a. load device of an evacuated vessel, an electrode of the hot cathode type capable of emitting electrons, and another electrode in the vessel, a connection between one pole of the said source and the hot cathode, a connection between the second electrode and one terminal of the load device, a connection between the second p le of the source and the other terminal of v the load device, and means for producing a magnetic field having a component substantially normal to the electron flow for controlling the electron migration between the two electrodes.

The combination with a source of alternating current and a load device, of an evacuated vessel, two electrodes of the hot cathode type and two cold electrodes positioned to co-operate one with one of the hot cathodes and the other with the other hot cathode, means for producing a magnetic field intermediate the electrodes'for controlling the flow ot' the thermionic current bctween the respective pairs of electrodes, a connection between one pole of the said source and one of the hot cathodes, a connection between the opposite pole of the source and the other hot cathode and a circuit connection between the two cold electrodes, and a connection between said circuit connection and the source including the load device.

3. A current rectifier comprising an evacuated vessel, two pairs of electrodes, one electrode of each pair being of the hot cathode type, a conductor connected to one of the hot cathodes and extending through the wall of the vessel, a conductor connected to the other hot cathode and extending through the wall of the vessel, a circuit connection interconnecting the two other electrodes, a conductor extending from said circuit connection and having at least a portion lying outside the vessel and means for producing a magnetic field substantially normal to the electron flow for controlling the flow of the thermionic current between the pairs of electrodes.

4. A current rectifier comprising an evacuated vessel, two conductors therein connected to opposite poles of a source of alternating current, means for heating each of said conductors to cause an emission of electrons therefrom, a third conduct-or positioned at an angle to both of said conductors, means for establishing a connection between said third conductor and the source of current and means for producing-a magnetic field in the path of the electrons to control their ath of migration relatively to the third con uctor.

5. A current rectifier comprising an evacuated vessel, two conductors therein connected to opposite poles of a source of alternating current, means for heating each of said conductors to cause an emission of electrons therefrom, two relatively cold conductors symmetrically located relatively to the hot conductors at an angle thereto, means for establishing a common connection between the said cold conductors and the source of current and means for producing a magnetic field in the path of the electrons to control the course of migration between the heated conductors and the relatively cold conductors.

6. A current rectifier comprising two hot cathodes connected to opposite poles of a source of alternating current, two metallic anodes disposed on a line which is substantially perpendicular to the line between the cathodes, said anodes being substantially perpendicular to said line, and a magnet for producing a field substantially at right angle .to both said lines and intercepting both of said lines.

7. A current rectifier comprising evacuated container, two hot cathodes therein positioned Opposite one another, a separate anode associated with each of said cathodes, each anode being located in electron-receiving relation to its associated cathode, means for supplying an alternating potentialvto said cathodes, and means for producing a magnetic field having a component substantially at right angles to the direction of the electron flow to thereby selectively direct the electron migration between each cathode and its associated anode.

8. A current rectifier comprising two hot cathodes capable of emitting electrons, a source of alternating current connected to said cathodes, two metallic anodes, one of said anodes being adapted to cooperate with one of said cathodes and the other of said anodes being adapted to cooperate with the other of said cathodes, and means for producing a magnetic field to selectively direct the electron migration from each-cathode to said two'electrodes, means for producing a magnetic field to direct the flow of electron current from each of said two electrodes relatively to said cooperating electrode.

In testimony whereof, I afiix my signature.

JESSE HUFF.

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