US2007939A - Rectifying apparatus - Google Patents

Description

BRASELTON RECTIFYING APPARATUS Filed Dec. 4, 1951 INVENTOR 15 struction.

Patented July 9, 1935 r RECTIFYING APPARATUS Chester. H. Braselton, NewYork, assignorto Sirian LampCompany, Newark, N. J., a corporation of Delaware Application December 4, 1931, Serial No. 5"78,938

2Claims. (01. 250-275;)

This invention relates to rectifying devices for alternating electric. currents. j One of the objects of the present invention is to providela rectifier which is simple in its con-v Another object isto provide a rectifyingdevice which is capable of use without any accessory appliances, but .which maybe. installed directly and in series witht the alternating power circuit .and'

with the appliances which are adapted for use in. connection with a rectifying current Another object'of the invention istoprovide a rectifier havinga' simple two outlet connection so that it may be used with an ordinary. screw socket, suchas are employed forelectric lamps. 1 ,Still another object. is; toprovideian improved "structure of a two-wayirectifying device, all of the elements of which are. included in a 'single container'or envelope.- v .Various other objects will. become apparent on consideration of the following descriptionand of-the accompanying drawing, in which Fig. 1 is a view'in elevation of one of the forms of my invention which maybe preferred;

. -.Fig. 2 is a diagrammatic-showing of the wave curve with current plotted against time;

Fig. 3- is a view of an improved two-way rectifying device; Fig.4 is .a wave diagram-of the device of Fi y Fig. 5 .is a diagrammatic view; indicating the .operationof the rectifying device of Fig.-3;and Fig. 6 is an; enlarged detail of :a-sectionof the coated conducting filament; T'

Referring to Fig. '1, there isillustrated a con- ,tainer. ll]; of: glass or similarmateriaLto an end ,of which i's-sealeda stem or support H..- To this .end is also mounted a base element having a ,screw threaded wall l2 and contactbase l3 separated by insulating material l4. Mounted on the'support ll: are three standards I5, l5,-and j H. Standards 15 Jan'dlfi are connected. below the stem, the standard l5 to thescrew wall I2, and the standard. IE. to the contact plate 13 of the base. Standard l5 extends to a point above the center of the bulb or envelope ill,and has a section l8 transverse thereto either welded to thestandard IE or formed in continuation there- "of. Between the end l9 ofthelsection l3 and the standard Iiiis connected a coiled conductor 20, preferably of tungsten, on which is acoating 2i of electron emitting material, such as oxides of barium, calcium, which are alkaline earth metwhen? otherfalklaline substances. This coating may be applied either externallyto the tungsure is againabout one-half micron.

sten coil. or internally as a coating within the coil, oras a rod of the oxide within the coil. Also, the oxide may be mixed with the conductor; that is, tungsten and calcium oxide or thorium oxide may be mixed together either physically or-by a chemical means, such as the com- ;bination of tungstic acid and thorium nitrate.

The standard H'forms a support for the tube 22 to whichit is welded or otherwise. attached, this/tube being concentric to the coated filament 29; A conductor 23 extends between the tube 22 and crossbar l8, this conductor serving also as a steadying means forthe tube.

Within the container H and immersing the various elements mentioned, is an atmosphere of gas or mixture of gases, which are preferably inert, chemically. These gases include neon, argon, nitrogen, helium and various metallic vapors, such as those of mercury,.caesium, rubidium and .calcium.- Chemica1ly pure gases should be emof barium nitrate with a binder'of sufiicient nitrocellulose dissolved in amyl acetate to hold the coating on the wire. The filament with this paste applied is then sealed in thebulb, the'contents evacuated by a vacuum pump, and the bulb and its contents heated by an oven placed over the same until the temperature of the bulb and contents is approximately 400 C. Electric current is'also passed through thefilament andheated up tored heat or about 600 C. The various gases evolved by this heating process are heated by a vacuum until the pressure drops to approximately one-half micron. The current is then increased through the filament to a bright red color, or about 800 C. The oven is then removed and the filament temperature increased to about 1290 C., pumping being continued until the pres- It has been found, as stated in my co-pending applications, when a coating such as described hereinabove is' heated by the passage of an electric current, an atmosphere of inert and, in general, ionizable gases; such as those hereinabove described, that a layer of highly activated luminescent gases forms about the conductor and its coating. This layer is, of course, highly conductive for electric current. and'forms aby-pass for electric current between the conductor segard 49.

upper length 4! of the standard 31. 'trated in the figure, the terminals 33 and 36 are adapted to be connected to the alternating ment l8 and the standard l6; that is, alternatively, current flows directly through the conductor 20 or through the conductor 23, tube 22, conducting gas layer and conductor 20.

In the case of an alternating current, however, when the current flow from the conductor is positive with reference to the standard 16, the tube 22 is positive and electrons readily emit from the'coating 2| on the conductor 29, thus ionizing the gas and permitting the flow of current from the tube to the conductor. 0n the opposite alternation of the cycle, however, the tube 22 is negative with reference to the average value of the potential of the conductor 20, and hence its effect is to restrain the electron emission from the coating so that there is a minimum or zero flow of current through the gases surrounding the coating 2!, with most of the current passing from the conductor 2| and from the standard IE to the conductor I8.

'Thewave form' ofsuch an alternating current no moving parts, and meets a variety of needs where an incomplete rectification is sufficient for the purpose.

In Fig. 3 I have indicated a full wave rectifier in which all the various rectifying elements are incorporated within a single container. Within the envelope container 36 is sealed a stem or sup port 3i, to which a base element 32 is attached having terminal pins 33, 34, 35, and 36. Within the tube and mounted on the support 3| are standards 31, 38, 39, and 40. The standard 31 is connected 'to the terminal 33, standard 38 to the terminal 34, standard 39 to the terminal 36, and the standard 40 to the terminal 35. Standard 31 is continued as a straight section 4|, having a bent-over section 42. Between the end 43 of the section 42 and the standard 39 is connected a coil 44, or plurality of coils, of tungsten, said 'coil having a coating of alkaline oxides similar to that described in connection with the rectifier of Fig. 1. This coating is applied in a similar manner and functions identically to form a layer of highly acti vated gases. The; electric current passing through the conductor heats the coating.

To the approximate mid-point of the conductor 44 a wire 46 is welded or otherwise attached,

which wire is electrically connected to the stand- Above the point of connection of the wire 45 a tube 4'! is supported by means of welded engagement with the standard 38. Similarly, below the point of engagement of the wire 46 with the conductor 44 is the tube 48 which similarly is attached to the standard 38. The standard 38, at its upper end above the tube 4?, is anchored in a glass bead 49 mounted on the As illuscurrent power source 59, and the terminals 34 and 35 to the load 5!, which is designed for use in a rectified or direct current. On inspection of the figure it will'be obvious that the power circuit traverses theconductor 44 and the rectified current, standard 40, wire 46, conductor 44, and either of tubes 41 or 48 and lead-in wire In the operation of this form of rectifier, when the activated layer of gases is formed about the conductor 29, for one value of the voltage of the alternation of the current cycle, the tube 48 is positive with reference to the conductor 28, while the tube 41 is negative to the same conductor. At such an instant the current flow between the tube 41 and the conductor will be practically zero, whereas current flow from the conductor and the tube 48 will be maximum. This causes current flow in the load circuit, including the load 5|, in the direction as indicated by the arrow. On the reverse alternation of voltage the current flow from the conductor to the tube 48 will be zero, while that from the conductor to the tube 41 will be maximum, this current flow through the load 5| being inthe same direction as in the prior alternation. There is thus obtained a rectified current of the type indicated in Fig. 4 where current value is plotted against time.

In Fig. 5 I have indicated diagrammatically the arrangement of Fig. 3, similar numerals referring to similar parts, and the layer of activated gases being indicated for one of the segments of the conductor.

' Fig. 6 illustrates in detail the section of the conductor showing the coating applied externally,

although, as hereinabove mentioned, it should be understood that other means of applying the coating may be utilized. The coating material may be applied in the shape of a core rod which may have angular cross-section, such as that of a triangle in which there would be three lines of contact against the interior of the coil. Other forms of the core' could be used, each modifying the amount of ionization which would be imparted by the electron emitting material. It also appears that the coating material acts as a second class conductor, and hence, because of its refractibility, permits higher conductivity than would otherwise be possible.

As shown in Fig. 6, the conductor is in coiled form, but I have found that a straight conductor operates advantageously for certain uses. I have indicated, also, an auxiliary connection at the ends of the conductor. This auxiliary conductor is in the shape of a coil 24 of one or two turns enclosing the ends of the conductor coil and having one end welded to the support. When the coating is ionized and a layer of conducting gases forms about the coating, this auxiliary conductor serves to carry a portion of the current and thus prevent overheating and possibly breaking or fusion of the end connections of the primary coil. I have also found it desirable, in some cases, to completely insulate the supporting standards so that there may not be any leakage of the current in the container. This insulation may be by means of glass tubing or by coating the conductors with insulating substances, such, for example, as described in my copending case, Serial No. 578,- 940, filed Dec. 4, 1931.

Various other modifications of the invention may be utilized, and I therefore do not desire to be limited to the modifications shown and described, other than such modifications as are disclosed by the claims hereto appended.

I claim as my invention: 1. In a rectifying device for full wave rectification a container; a support mounted therein; a

plurality of standards mounted on said support;

a conductor mounted between twoof said standards; a connection from the mid-point of said conductor to another of said standards; two tubular elements surrounding said conductor but displaced from each other and-mounted on another of said standards; an atmosphere of ionizable gas within the container; a coating of electron material on said conductor; and terminal elements connecting said standards to points external of the envelope, the breakdown potential of said gas. being less than that necessary to bring the coating on said conductor to electron emitting temperature. 1 r

2. In a rectifyingdevice for full wave rectification, a container, a support therein, a conductor mounted on the support, plural interconnected conducting elements adjacent the conductor but displaced from each other along the conductor, external terminals, electrical connections between the ends of the conductor and to the said terminals; additional connections between the approximate midpoint of the conductor and another of said terminals, a connection-between the conducting element and another of said terminals, a coating of electron emitting material containing oxides of the alkaline earth metals. on said, conductor and an inert ionizable gas within the container, the breakdown potential of said gas being less than that necessary to bring the coating on said conductor to electron emitting temperature.

= CHESTER H. BRASELTON.

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