US1774455A - Electric condenser - Google Patents

Description

Aug. 26, 1930, s, RUBEN 1,774,455

ELECTRIC CONDENSER Filed Oct. 19, 1925 @51 h is elf/town conduction eflect,but due to the electro hysical reaction between the contacting sur aces,

Patented Aug. 26, 1930 UNITED STATES PATENT OFFICE SAMUEL RUBEN, OF NEW YORK, N. Y., ASSIGNOR TO RUBEN PATENTS COMPANY, OF NEW YORK, N. Y., A CORPORATION OF DELAWARE ELECTRIC CONDENSER Application filed October 19, 1925. Serial No. 63,203.

This invention relates to electrical condensers, and particularly to that type in which an electrochemically-formed film separates the conducting elements.

'5 The invention has for its. object generally an improved electrical condenser of the character indicated which is efficient, durable, I having high capacity per unit of volume and is readily manufactured.

Among other objects is that of providing a condenser with initial and even distribution of potential, if the sections thereof are connected in series, and in which greater contact area between the elements is practicable due to the fact that negligible leakage comes into existence incident to a punctured or incompletely formed film between the contacting electrodes.

The invention accordingly comprises a device which possesses the features, properties, and relation of elements, which are exemplified in the following detailed disclosure, the scope of the application of which is indicated in the claims. The fundamental purpose in this invention is to obtain a condenser device having a maximum capacity and a minimum leakage, both of-which are functions of the contact potential difference between the contacting electropositive and electronegative electrodes.

It was found that in a,condenser having aluminum electrodes and cooperating elements of cupric sulphide in contact and under such pressure as to effect maximum surface contact and minimum electrical resistance of the materials, there is relatively high leakage current and low operating potential, and that by increasing the contact resistance between the electrodes, the leakage is materially reduced, not because of the ohmic resistance which permits an increase of operating potential with a neglible current flow, in creased contact potentialbeing thus available for the formation of an intervening high resistance surface film.

There are several practicable methods for treating the electrode surfaces for increasing the contact resistance which I have developed and which allow the application of higher potential and give low leakage currents, such By connecting the electropositive electrode trode, such as powdered silver sulphide applied mixed with an inert binder; by amalgamating the electropositive electrodes with mercury, as by immersion in a solution of mercuric chloride; by oxidizing the electropositive electrode surfaces; and by using an alloy in the electronegative electrode which has a higher specific resistance than that of either electrode, as by amalgamating the copper with zinc before treating the copper to a temperature above 500 degrees C. in an atmosphere of sulphur vapor.

In the present invention the desired obiects are preferably accomplished by the use of elements "or compounds of the sixth periodic chemical group, in the electronegative electrode material, those elements thereof which are conductive; as for example, tellurium and selenium may be used in their normal state; and those elements which are nonconductive; such as, oxygen and sulphur may readily be used when in combination with a metal forming a conductive compound; such, for instance, as oxides, sulphides, tellurides and selenides. These substances give asymmetrical electrical conductive effects when coupled with a relatively electropositive element or compound; such as, for example, aluminum, magnesium, calcium and zinc; the greater the electrochemical divergence between the substances used respectivelyfor the electropositive electrode and the electronegative electrode, the more effective will be the electrostatic capacity of the device.

Thepresent invention employs as an electronegative electrode element, a metallic compound having an electronegative component of the character above described but is (preferably one of cupric sulphide, the b0 y of pure cupric sulphide.

It will be found that an electrical condenser constructed inv accordance with the present invention provides a device of high capacity which is not limited by leakage. It is espewhich offers a certain resistance that is increased by combining it with a material having a higher specific resistance. For the electropositive electrode is preferred aluminum, although magnesium, calcium and zinc may be used.

A practicable method for providing such an electronegative electrode is found to be that of employing a copper, alloy in which the alloy material has an inherently higher resistance than that of pure cupric sulphide, and thereafter heating the compound to approximately 800 degrees C. in the presence of sulphur, and finally permitting the mass to cool. Thus, a copper compound is produced, the body of which has a higher specific resistance than that of pure cupric sulphide; such a body will not require the use of a facing or intermediate oxide layer.

While other alloys may be employed for this purpose, it is particularly desirable to form the cathode from a copper compound, copper being a preferable element, readily forming the desired compounds withsuch substances as sulphur, selenium, tellurium or oxides. The material added to vary its final resistance can be another metal, such as silver, tin, zinc, antimony, or any other material that will, of itself, form a sulphide or compound having a different electrical resistance than copper sulphide. The best results have been obtainedby using as the sulphide material, an alloy of copper and zinc of the proper proportions, the alloy being treated as above described. The element is further improved, if, before being so treated, the alloy is slightly amalgamated with mercury which serves to toughen the final product besides efiecting a more complete crystallization of the cupric-zinc sulphide. To increase the surface resistance, the electropositive element may profitably be slightly oxidized.

In employing tellurium, selenium and the tellurides and selenides, probably the best results are obtained in combination with magnesium and the latter may be elfectively used with copper alloy compounds as the opposing electrode; that is, the condenser may employ copper telluride or copper selenide as the electronegative electrode and magnesium as the electropositive electrode. in combination with sulphides, aluminum is preferable to magnesium.

My invention then, comprises an electrical condenser composed of a film-forming electronegative compound as one electrode in close surface contact with an electropositive compound as the opposing electrode, the electronegative material bein a cupric sulphide compound of higher specific resistance than cially adapted for instantaneous or intermit tent use.

Among the advantages of a condenser h corporating the subject matter of the present invention, it will be obvious that no fern-1a tion or ageing process is required, and that no failures will occur incident to the use of the device after periods of use or non-use. Greater pressure may be used on the elements to increase the uniformity of contact.

Thus, among others, the objects specifically mentioned are accomplished, and since certain changes in carrying out the above process and certain modifications in the elements which embody the invention may be made without departing from its scope, it is intended that all matter contained in the above de scription .or shown in the accompanying drawings shall be interpreted as illustrative rather than in a limiting sense.

It is also to be understood that the following'claims are intended to cover all of the generic and specific features of the invention described, and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween.

Referring to the drawing, Fig. 1 shows a plan view of the condenser adapted to alternating current circuits; Fig. 2 shows a section view at line 2-2; and Fig. 3, a section view of the device at line 3P3.

Referring more particularly to Fig. represents a series of aluminum electrode elements connecting at terminal, B. 1 rep resents a series of opposing aluminum electrodes, 4 being powdered cupric-zinc sulphide filling the space between these electrodes, all being located within dielectric walled case, C. If the film formed between the contacting elect-ronegative and electropositive materials be punctured, or otherwise injured, it is repaired by sulphur given up to it by the excess sulphur of the curic-zinc sulphide as the excess potential recedes to normal values. In this respect the insulating film is self-heatmg.

What I claim is:

1. An electrostatic condenser comprising, in combination, a plurality of electrode elements of an electropositive material, and interposed film-forming material comprising an electronegative compound of an element of the sixth periodic group of chemical elements with a copper-zinc alloy, said electrode elements being disposed to receive electric charges ofopposite polarities.

2. An elect ostatic condenser comprising, in combination, a plurality of electrode elements of an electropositive material, and interposed film-forming material of an electronegative compound of an element ofthe sixth periodic group of chemical elements with copper and a metal of higher resistance than copper, said electrode elements being d sposed to receive electric charges of opposite polarities.

3. An electrostatic condenser comprising, in combination, a plurality of electrode elements of an electropositive material, and interposed film-forming material of a powdcred clectronegative compound of the sulphur subgroup in the sixth periodic group of chemical elements with a metal containing copper and zinc, said electrode elements being disposed to receive electric charges hav ing opposite polarities.

4. An electrostatic condenser comprising, in combination, a plurality of electrode elements composed of sheet aluminum, and interposed powdered film-forming material consisting of an electronegative compound of sulphur with copper and zinc, said electrode elements being disposed to receive electric charges having opposite polarities.

5. An electrical condenser comprising, in

combination, an electropositive electrode of an electropositive material and an electronegative electrode of a crystalline compound composed of an alloy of copper and zinc sulphided.

6. An electrical condenser comprising an electropositive electrode of an electropositive material in surface contact with an electronegative electrode of a conducting crystalline compound composed of an alloy of copper with a resistance increasing metal combined with sulphur.

7. An electrical condenser comprising an electropositive element connected to one terminal of an electric circuit, and another electropositive element of like material adapted to be connected to the opposite terminal of said circuit, and having the space between said elements .filled with a sulphide compound of an alloy. of copper and zinc.

8. A unitary structure comprising a plurality of conducting members of a relatively electropositive metal, insulating means for supporting and maintaining said members in position, a closed receptacle, and a filling of a sulphide compound of copper and zinc.

9. An electrical condenser comprising, in combination, an electropositive electrode and an electronegative film-forming electrode composed of a cupric sulphide compound of higher specific resistance than pure cupric sulphide, said electrodes being disposed in cooperating surface contact.

Signed at New York city, in the county of New York and State of New York, this 9th day of October, A. D. 1925.

SAMUEL RUBEN.

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