US1872214A - Rectifying apparatus - Google Patents

Description

Aug. 16, 1932. H. s. ANDRE RECTIFYING APPARATUS Original Filed Oct. 1, 1926 I jwerig 'i e/z rd 6: 14/? 7'6 W @AMM mmw mim w g 4 N A E, 5:... 5 w tlQu .7 ill Patented Aug. 16, 193? I 1,872,214

UNITED STATES PATENT OFFICE 1mm G. mm, or rams, armor:

BEGIII'YIN G .AI'PARATUS Application fled October 1, 1986, Serial No. 180,924. Renewed Kay 11, 1931.

The present invention relates to electrical ing the subject of the present invention in apparatus and in particular to alternating which, current rectifiers in which two metals of dii- Fi 1 is a vertical section of the improved ferent character are employed as electrodes, recti er; the metals fulfilling alternately the function Fig. 2 is a section taken on line 2-2 of of cathode and anode. Fig. 1;'

In my Patent No. 1,830,500, dated Novem Fig. 3 represents a vertical section of anbeer 3, 1931, of which this is a continuation other embodiment; while in part, I have disclosed a rectifier one elee- Fig. 4 shows a section taken on line 4-4.- trode of which comprises a metallic colloid of Fig. 3. 1 while the other is formed of a material that Referring to the illustration, the invenwhen subjected to an oxidizing agent yields n in its pr ed m n i ts of glass a compound which cooperates with the other tube or envelope 2, the ends of which are electrodes to form a unilateral conductor. o ed by stoppers 3, 14 made of rubber or 15 In the application identified, I have also bakelite. The upper stopper has an opening stated thc presence and manner in which longltudinally 0f the principal axis of the derived of an element in colloidal form makain r for the introduction of fine tube ing physical contact with. one of the electrodes 4 0 n ulafilng material, as glass or rubber. and in particular with the cathode. Aph 'lec lfier proper consists of cathode 13 paratns made according to the foregoing made preferably 0f cylindrical form t0 fit pecification has the property of rectifying the diameter 0f tube 2 and Of a material alternating current of comparatively lar exhibiting strong electrolytic oxidation, for amplitude. example aluminum, nickel or one of its al- It has been found in practice that the col- QX as nlcke-l-silicoll, containing 25 to loidal element instead of being introduced 1l COI1, and nickel-iron. The cathod i i physically into the space surrounding th Intimate contact with colloidal anode 10 th d as l i d i my li ti formed 1n place by electrolytic action occuru, may b f d i place b th ti f ring 1n a manner to be described hereinafter. th current t b tifi d th li i ti Reference character 8 deslgnates a conductor a tediou te in ufa tu of material, as silver or graphite, the oxida- Other changes in construction will be noted ti011 p nd f which are good conin the following descripti n, f l ductors of electrical energy and able to withwhereas in the application r f r d t th stand attack by acid, surfacial oxidation excathode is sealed within the surrounding cas epte As will be noted from the drawing, ing by means of sulphur or other a orph u electrode 8 is of rectangular cross-section but material, manufacturing experience has may also take a cylindrical form and is SUS- shown that other methods of securing the pended in the glass envelope by lead wire 5 cathode are preferable. passing through fine tube 4. The lead wire is The invention described hereinafter has preferably of the same metal as the electrode for its purpose a design of rectifier o erating to which it is attached.

on the colloidal rinciple which 0 ers sim- For electrolyte 6, which completely subplicity of menu acture and ease of operamerges electrode 8, I prefer sulfuric acid tion. having concentration of approximatel 66 Other features consist in novelty of con- Baum, although it is to be understoo that struction combination and arrangement of all fluids capable of producing oxidation of parts hereinafter described and claimed, the metals, and any degree of concentration comes advantages of which'will be obvious 'to those within the purview of my invention. I skilled in the art. In order that the solution may be sufli- The accompanying drawing illustrates an ciently strong to prevent permanent electrolexemplary embodiment of the device form-. ysis and at the same. time, weak enough to preserve the electrodes from dissolution by attack, I combine with the acid an anhydrid in approximately 20% proportion, preferably that of phosphoric acid.

At 7, I have indicated a quantity of glass wool so-called, effectively to hold by absorption acid superfluous or in loose form to the end that the rectifying unit may be handled without spill. Furthermore, the interstices between glass fibres allow passage of the gas evolved during the initial process of electrolysis as will be explained later. The gas may escape to the atmosphere through fine tube 4.

Cathode 3 is secured within the envelope by filling 14 of rubber poured hot in place, or bakelite, which makes firm contact with the glass wall by baking. A seal in addition to element 14 is provided by layer 15 of plastic compound.

The entire rectifying unit is secured preferably in a base of the Edison screw type by plastic material 16 about the periphery of which member 12 makes electrical connection by molybdenum lead 17 with the cathode. It is obvious, however, that under certain conditions a bayonet-slot type of base may be advantageously employed. The base terminates in metallic member 19 to which connection is made from the anode by molybdenum lead 9. For the purpose of protectmg the unit from external injury and also to insure convenience of handling, I provide a container or casing 1 of a metal, which shapes conveniently, as lead or brass.

This container is open to the atmosphere through apertures 20 and secured to the base by a close fit in metallic annular ring 11. Inasmuch as the principal roles of the enclosing envelope are those of protection and the furnishing of a convenient arrangement for making contact with external circuits, its shape and form may be varied extensively, and I do not intend to limit myself to that shown.

The operation of my device is not wholly understood from the theoretical standpoint, but I believe it to be as follows:

When alternating current is initially applied to the cathode and anode, electrolytic phenomena take place as evidenced by the evolution of gas in the acid. The silver conductor which initially performs the function of anode appears to disintegrate and in powdered or colloidal form is attracted to the nickel cathode Where a relatively thick deposit is formed. This deposit is in the nature of a finely divided mass of metal, each particle of which is partially surrounded by liquid.

As indicated on the drawing, the colloid, when examined microscopically, appears to build in a formation resembling the roots of a tree spreading out from the trunk. This action continues until the entire space between anode and cathode is bridged by colloidal arms of irregular cross-section, hav ing their inception at the silver anode. It is apparent, however, that conditions of operation, as voltage and fre uency of the electromotive force applied uring the preliminary period, also the size, shape and position of electrodes, each have a marked effect on the manner in which the powdered mass is obtained.

As representing another form which the colloid may take, in Fig. 3, I show an electrode arrangement, i. e. cathode uppermost,

reversed from the position assumed in Fig. 1. Due in part to gravitational forces, the particles of silver seem to con regate without definite outline between the e ectrodes, a portion falling to the bottom of the glass envelope. Inasmuch as the latter and the outer metallic shield form no part of the present invention, I will not describe them.

Referring to Fig. 4, the section of cathode will be noted as a cross which shape I have found operates beneficially when the electrodes are in the positions shown.

The action just described extends over a short period of time and is a condition precedent to complete rectification of the applied electromotive force, although as a matter of fact I find that partial rectification sets in almost immediately upon application of the alternating potential.

At the expiration of the preliminary colloid forming period, electrolytic action a pears to cease, and as far as I have been ab e to determine, the rectifier eventually is devoid of electrolysis. In this specification I intend electrolysis to include disintegration of electrodes by an electrolyte either with or without the formation or deformation of a superficial oxide layer. The primary function of the electrolyte, however, is to oxidize the electrodes, which being of dissimilar metal will be affected unegually. In its subsequent operation as a recti er, the anodal function is transferred to the colloid, electrode 8 assuming the role of a mere conductor or lead.

Now I have found that oxidation compounds of nickel and its alloys have the desirable characteristic of permitting current flow in one direction only. This property appears to be utilized to great advantage w en operating inconjunction with a colloidal anode that forms many points of physical contact with the adjacent oxide film, ofiering unilateral conduction of current in aggregate, of a high order.

The passage of current from anode to cathode may be explained on the theory of transference of atoms of oxygen direct from the nickel to silver while the insulating property of the nickel oxide film, upon reversal of potential, prevents current passing in the opposite direction. While the silver is also acted upon by an electrolyte, the resulting compound, oxide of silver, conducts current readily in both directions. Thus the rectifying feature is attributed at present solely to the oxide layer covering the nickelous cathode.

This explanation, however, is offered purely as a matter of interest and which present experience with the rectifier has seemed to dictate.

Whatever are the true principles involved, the fact remains that a rectifier made according to the specification set forth utilizing a nickel-silicon cathode of .093 diameter, a silver anode of .01 square inches cross-section, on test continuously passed rectified direct current of one ampere, delivering a potential of six volts with a loss in the tube of approximately one watt. Such showing, of course, was made after the colloid was formed complete and substantially all electrolytic action had ceased.

While I have illustrated'the electrodes rela- 6. A unidirectional discharge device comprising a cathode having an extended ex terior area with a unilaterally conducting layer and a bilaterally conducting anode in contact with said area reduced to sub-divided form by passage of current between sa1d anode and said cathode.

Signed by me at Boston, Massachusetts, this 17th day of September, 1926.

HENRI G. ANDRE tively close together, it will be appreciated by those skilled in the art, their shape, size and spacing may be varied to meet a specific performance or design. The device disclosed is readily adapted to operate in conjunction with standard circuits utilizing half or full wave rectification. For rectification of both half waves it is obvious that two anodes and a cathode or two cathodes and an anode may be combined for convenience in a single receptacle.

I claim:

1. A unidirectional discharge device having a film-forming electrode and an additional non-filmforming electrode with a mass of finely divided conducting material substantially bridging the space therebetween characterized in that the particle mass comprises a distintegration product ofthe I other electrode and is formed in situ.

2. A unidirectional discharge device comprising a cathode having a unilaterally current conducting layer and a non-film-forming anode associated therewith reduced to subdivided form by the action of the current to be rectified.

3. A unidirectional discharge device comprising in combination, a cathode, the oxidation product of which constitutes a unilateral conductor of current, an anode Whose oxide is conducting associated therewith, a member composed of minute particles formed in place and making contact with said cathode and a slightly ionizable liquid to produce oxidation of the latter.

4. 1m an electrical apparatus, the combination with a non-film-forming anode, of a film forming cathode associated with the said anode and immersed in an electrolyte whereby gas is evolved, and means for absorbing the electrolyte including a fibrous material, the strands of which permit gas flow, the said anode being reducible to par-

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