US1617177A - Production of electrical variations - Google Patents

Description

eh 7 c. cs. SMITH PRODUCTION OF ELECTRICAL VARIATIONS Original Filed May 5. 1921 Sam vmew vx Patented Feb. 8, 1927.

' -UNITED STATES MENTS, TO RAYTHEON MANUFACTURING COMPANY, SETTS, A CORPORATION OF MASSACHUSETTS.

CAMBRIDGE, IIIIZASSACEU- PRODUCTION OF ELECTRICAL VARIATIONS.

Application filed May 3, 1921, Serial No. 466,518. Renewed January 11, 1927.

Smith Serial No. 415,536, filed October .8,- 1920, and Serial No. 418,263, filed October As disclosed in the applications above re- Fig. 1 represents a section in elevation of a ferred to, the employment of curved electrodes immersed in a gas with all available paths for conduction through the gas short i and of the order of magnitude of the mean free path of the electrons and with all paths through the insulating medium sufficiently long to prevent breakdown and with a magnetic field introduced in the space separating the surfaces of the electrodes at different potentials permits conduction to freely take place between the surfaces of the electrodes in one. direction but not in the oppo-r site direction, thus alfording a simple and convenient means .for the rectification of alternating currents. The ability of such a device to successfully rectify depends, as

stated, upon the separation of the electrodes and in addition upon the strength and character of the magnetic field and the pressure of gas in which the electrodes are immersed.

It has been discovered-that if the lines of force of the magnetic field are curved and concave toward the cathode the electron discharge is localized and concentrated in a mannerto markedly improve the rectifying.

qualities of the? apparatus, more particularly by greatly increasing the permissible range of magnetic field over which rectification can take place.

In one form of the invention a magnetic field is introduced between two electrodes with curved lines of force extending lengthwise of the electrodes and concave toward one of the electrodes in such a manner that the lines of force intercept the surface of this electrode at two points spaced length- .wise of the electrode. With such a construction and with an electric field created between the electrodes, conduction takes a manner that all paths-. available for conconduction tends to become concentrated or bunched in the region beneath the center of the arches formed by the curved lines of force; The region in which conduction is concentrated may be indicated approximately by a radlal lane intersecting the arches of the lines of ibrce at approximately their central points. 7'

Referring to the accompanying drawings tube embodlying the principles of the invention, and ig. 2 is a diagrammatic view illustrating the .tube employed as a rectifier in a simple circuit.

The tube shown in the illustrated embodiment of the invention comprises a gas'filled receptacle 10 of. suitable form haying cooperating cylindrical electrodes 12 and 13 received therein. The electrode 12' is supported "concentrically withinv the receptacle by supporting members 14' which extend- 5 from the inner surface of the electrode to a base portion'16 forming a part of the receptacle. The cooperatingv electrode 0 linder 13 is supported in alikemanner y members 18 ;which extend toa base portion 20 formed in the opposite end of the receptacle 10. The two electrodes; are .designed with respect to one another in such duction through the'gas' are short and all pathsthrough the insulating medium are sufficiently long to avoidbreakdown. The

inner electrode cylinder 12 is connected with a lead', 22 pas'sing outwardly through the base 16 and the outer electrodecylinder 13 is connected with a lead'l24 passing outwardly through the base-20 at the opposite end of the rece tacle. Y

A magnetic eld of suitable strength and having its lines of force curved and concave with respect to the outer electrode is introduced into the space separatin the two electrodes to cause gaseous con uction to take place when the outer electrode is negative and to prevent gaseous conduction when the inner electrode is negative. This magnetic field may be conveniently supplied by annular pole pieces 26 and 28 which encircle the receptacle 10, as indicated, the magnetic field being created in the space between the upper and lower pole pieces. A plurality of permanent ma 'nets 30 and 32 operate in conjunction w1th the pole pieces voltages and conduction cannot take place.

The thee underlying this type of construction is lieved to be essentially as follows: When the outer cylinder, toward which the lines of force are concave, acts as the cathode electrons starting from a region adjacent. the upper or lower portions of the cylindrical cathode are deflected by the magorigin.

netic field toward the center, these electrons in general producin a positive ion nearer the center of the arc es than their points of 'These positive ions dropping to the cathode liberate more electrons which in turn are deflected toward the center of the arches,-this process being repeated until the discharge .is concentrated in the region adj acent the radial plane indicated by dot and dash lines. Electrons liberated in this plane are not deflected either above or below it but tend to liberate ions in the plane of origin. It will thus be obvious that the discharge tends to build up with the greatest intensity in the region immediately adjacent.

to the meridian plane. On the other hand, electrons leaving the inner cylinder when the latter acts as a cathode are dispersed and.

dissipated away from the center of the arch by the curvature of the magnetic field to a region of lesser magnetic field so that positive ions liberated by the impact of these electrons in turn liberate electrons in a region of small magnetic field and there is. no tendency for a continued discharge to take place. It should be understood that the curvature or distortion of the path of the electrons lengthwise of the electrodes by a magnetic field of the character described is in addition to andapart from the distortion of the path of electrons by the magnetic field in planes extending radially of the electrode members, as previously described in certain of my other copending applications. The introduction of auniform or non-symmetrical magnetic field between two electrodes tends to cause rectification but does not necessarily tend to localize or concentrate the conduction in a single plane as is the case with the present construction.

Fig. 2 illustrates a simple form of circuit embodying the tube as a rectifier, this'circuit comprising an input circuit indicated rectifies'the high volta e alternating current delivered thereto. This output circuit may be connected with any desiredform of loadcircuit (notshown) to utilize the high voltage current so rectified.

Although the illustrated embodiment ofthe invention is shown in a tube having the lines of force of the magnetic field curved with respect to the electrode surfaces, it should be understood by art that the broader pr1nciples of the invention are susceptible of embodiment in any tube designed to cause the cathode surface to be intersected at a plurality of points by the lines of force of the magnetic field, as for example a tube having a curved cathode surface intersected at a plurality of points by the lines of force.

. The radial surface of electrode 12, which extends outwardly from the diameter of the smaller active portion of electrode 12 to the diameter of the outer tubular electrode 13 intermediate the reentrant stem 16 and the space between the two electrodes where the electrical discharge occurs, together with the peripheral surface which extends lengthwise of the tube from the outer edge of said radial surface in close juxtaposition to the wall of the tube, with a thin gas space be--.

tween the peripheral surface and the tube wall, protects that portion of the tube where the conductor 22 enters the tube from the electrical discharge and the radiation of light and heat therefrom.

I claim:

1. An electrical apparatus, comprising innerand outer electrodes immersed in a gas, means for creating an electric field between the surfaces of the electrodes, and means for introducing a magnetic field betweenv the electrodes, having the lines of force between the electrodes curved and concave toward the surface of the outer electrode.

' 2. An electrical'apparatus, comprising a hermetically sealed as-filled tube, inner and outer electrodes 0 circular cross-section supported in concentric relation within the tube, means for creating an electric field between the surfaces of the electrodes, and means for introducing a magnetic field between'the electrodes, having the lines of force curved and concave with respect to the surface of the outer electrode.

3. An electrical apparatus, comprising ahermetically sealed gas-filled tube, inner and outer electrodes of circular cross-section positioned within the tube, means for creating an electric field'between the electrodes, and means for introducing a magnetic field between the electrodes, comprising annular pole pieces surrounding'the outside of the receptacle and spaced apart lengthwise of the electrode.

4. An electrical apparatus comprising cothose skilled in the operating electrodes immersed in a gas, means for creating an electric field between the surfaces of the electrodes, and means for introducing a curved magnetic field between the electrodes having the lines of force cutting one electrode and arranged to concentrate ionization in a region restricted longitudinally of the electrodes.

5. An electrical apparatus comprising cooperating electrodes immersed in a gas, means for creating an electric field between the surfaces of the electrodes, and means for introducing a magnetic field between the electrodes with the lines of force extending in such a manner and of such a character that ionization is dissipated with one of the electrodes acting as the cathode.

6: An electrical apparatus comprising electrodes immersed in a gas and having opposing surfaces separated by a distance which is short and comparable to the mean free path of electrons in the gas, means for introducing a magnetic field between the electrodes, the magnetic field and the electrode surfaces being curved relatively to one another. I

7. An electrical apparatus comprising a gas filled ieceptacle, means for impressing an electric field in a portion of the gaseous region limited in length to a distance comparable to the mean free path of electrons in the gas, and means for introducing a magnetic field in the gaseous region having the lines of force curved.

8. An electrical apparatus comprising electrodes immersed in a gas and separated by a distance comparable to the mean free path of the electrons in the gas. and means for introducing a magnetic field between the electrodes with the lines of force cutting one of the electrode surfaces at a plurality of points.

9. An electric discharge tube having a reentrant stem, a tubular electrode having one end directed towardsaid stem, an electrode surface presented to the interior of said gas space.

the tubular electrode and a surface extend- 1 ing lengthwise of the tube from the outer edge of said transverse surface.

10. An electrical discharge tube having a reentrant stem, a tubular electrode having one end directed toward said stem, an electrode surface presented to the interior of said tubular electrode, a conductor extending through said stem for conducting current to said surface, an annular metallic surface presented to the space between said tubular electrode and said electrode surface intermediate said stem and said electrode surface, said annular surface having a radial dimension at least approximately as great as the difference in diameters between said tubular electrode and sa .d electrode surface, and a surface extending lengthwise of the tube from. the outer edge of said annular surface in close juxtaposition to the inner surface of the tube.

11. An electrical discharge device having a reentrant stem, an electrode opposite said stem, a smaller electrode surface between said stem and electrode, a shielding surface intermediate said stem and electrode surface, said shielding surface extending outwardly from a diameter substantially confined to that of said electrode surface to a diameter at least substantially as great as that of said electrode, and another shielding surface extending longitudinally of the tube from the outer edge of said shielding surface, the longitudinal surface being surrounded by a thin CHARLES G. SMITH.

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