US1086102A - Method of transforming electrical energy. - Google Patents

Description

E. WBINTRAUB. METHOD or TRANSFORMING' ELECTRIGAL ENERGY.

APPLICATION FILED FEB. 26, 1902.

1,086,102. Patented Feb. 3, 914.,

Wnmassas INVEHTOR ligechiel Wein+mub UNITED STATES PATENT OFFICE.

EZECHIEL WEINTRAUB, OF SCHENECTADY, NEW YORK, ASSIGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

METHOD OF TRANSFORMING ELECTRICAL ENERGY.

Specification of Letters Patent.

Patented Feb. 3, 1914.

Application filed February 26, 1902. Serial No. 95,661.

To all whom it may concern Be it known that I, EZECHIEL Wam- TRAUB, a subject of the Czar of Russia, residing at Schenectady, county of Schenectady, State of New York, have invented certain new and'useful Improvementsin Methods of Transforming Electrical Energy, of which the following is a specification.

The invention hereinafter described and claimed relates broadly to the transformation of electrical energy, and more especially to ,the product-ion of light through the medium of vaporous or gaseous matter main-- tained in a luminescent condition by electric energy. In lamps wherewith I practise my invention perhaps the most generally useful and convenient material to employ is the vapor of mercury and it is of this vapor that I chiefly make, use, though it is of course to be understood that I do not wish my invention to be limited to the employment of this vapor only.

In lamps of the character described, various difiiculties and disadvantages are attendant upon the means heretofore employed for starting the arc. The usual method of startlng, of which of course there are various modifications, is to impress upon the electrodes of the lamp, for a certain period or periods, a high electro-motive force, many times greater in value than the normal electro-motive force at which the lamp is intended to operate. This starting electromotive force operates or at least. appears to operate to break down the high initial resistance or opposition to current flow between the electrodes of the lamp whereupon the lamp starts.

My present invention, among other valuable features, provides a means whereby the arc, in a lamp of the type mentioned, may be started into operation by the utilization of moderate electro-motive forces, such for example as those normally employed by the lamp. though my invent-ion permits a wide range of starting electro-motive force.

Before passing on to the explanation of my invention in detail it may perhaps be I well to state first certain considerations the are by projecting into its ofmercury or other similar vapor.

which may aid in explaining the theory of operation-of the lamp. In'general, I start path the vapor It is not suflicient that this vapor should be of that form which would be produced by the.

evaporation of mercury by heat, for when in this'condition it has been found that the mercury vapor is practically, or at least nearly, a non-conductor for the electric current, so that the presence of such vapor not only does not help the lamp to start, but actually hinders it. Something more is neces'. sary and this necessity requires that the mercury should be not only in the form of a vapor but this vapor should be in an ionized condition. It is perhaps impossible to state exactly What this condition is but it will be sufficient for the present purpose to state that when in the ionized condition the mercury vapor is a good conductor of the electric current, whereas ordinary mercury vapor is practically a non-conductor. I have found that such ionized mercury vapor may be produced within the inclosing or containing member of the lamp by means of a supplemental or auxiliary mechanism operating at comparatively low electro-motive force and that this ionized vapor once produced immediately causes current to pass between the main electrodes of the lamp, which thereupon operates normally. The lighting up of the main tube, so far as the eye cansee, is or may be simultaneous with the initiatory production of the ionized vapor by the supplemental or auxiliary device.

After the lamp has been started, the supplemental or auxiliary mechanism or means for generating the ionized vapor may be cut out of circuit or otherwise put out of.

action if desired, and this operation may be performed either manually or automatically. I have found however that if this auxiliary or supplemental source of ionized vapor be continued in operation a most important advantage may be secured. When the lamp is maintained in circuit under certain conditions either of impressed voltage or of current supply, it may become unstable in action. This may happen for example when the lamp is made to run with reduced current, in which case it may frequently flicker or go out entirely. If, however. the auxiliary or supplemental source of ionized vapor be maintained in action. this instability disappears and the lamp will be steady and stable in operation throughout extremely wide variations in impressed voltage or current supply. I account for this on the theory that any tendency of the lamp to go out, or any tendency to undue reduction of current, is instantly counteracted by the supply of ions produced by the supple mental source, these ions immediately bringing back'the flow of current to its normal value.

My invention further comprises various features for assisting the beneficial effects of the starting means, particularly useful in relatively long lamps. In carrying out this last feature of my invention I provide one of the electrodes of the lamp with a conducting medium extending in the direction of the other electrode. This conducting medium may be in the form of a carbon filament, though in this connection I may employ a filament, rod, or other suitably shaped conductor of carborundum or of graphite or of mixtures of carborundum, graphite and clay since these materials possess the valuable advantage that they do not occlude gases to any extent nor do they, by the action of heat, become chemically changed in such a manner as to produce gases. This advantage is extremely important since, in

lamps to which my invention is to be applied, it seems to be necessary that the vacuum or degree of exhaustion should be as near absolute perfection as possible. Thus,

I get good results in long tubes with a vacuum represented by 1/1000 of a millimeter of mercury.

My invention comprises also other valuable features together with various details of construction and arrangement, all of which will be set forth more specifically in the following description, taken in connection with the accompanying drawings, in which Figure 1 represents one embodiment of my invention, and Fig. 2 an arrangement containing certain additional features.

In Fig. 1 a lamp is shown, the main body portion of which consists of a straight tube 1 of somewhat indefinite length as indicated conventionally by the dotted lines 2, 2. The length of the tube varies in accordance with the voltage in connection with which the tube is to be used. The lower end of the lamp contains a body of mercury 3 extending down into a contracted neck 4 of the tube, with the lower end of which communicates a terminal 5 which may be of platinum or other suitable material having the proper coeflicient of expansion. The body of mercury 3 above referred to, constitutes one of theoperative electrodes of the lamp and is connected with the negative conductor leading from a source of direct current, whereby it acts as a cathode. At the opposite end of the tube is the anode 6. This may be formed of various materials such as iron, silicon, carborundum, or mixtures of carborundum, graphite and clay, carbon, graphite or..a mixture of graphite and clay. Graphite, carborundum and clay possess the advantage that they do not tenaciously retain occluded gase nor do they, when acted upon by heat, undergo such chemical change as would give rise to the production of gases, the advantage of which is set forth above. The electrode 6, to which reference has been made, is connected by a platinum or other suitable wire 7 passing through a glass wall into an exhausted chamher 8 through which, by means of a coiled or extensible wire 9, connection is made with the exterior terminal 10 of the lamp which terminal is connected to the other pole of the source of direct current. The object of the supplemental exhausted chamber 8 is to relieve the pressure around the joint between the platinum wire 7 and the glass surrounding it, thereby reducing, as far as possible, any tendency toward leakage of air into the main tube. In connection with the main lamp electrodes thus described, there will be noticed an additional or supplemental elect-rode, consisting in this instance of a body of mercury 11, normally separated from the mercury 3 but in proximity thereto, and contained within a cavity 12 from which depends a tubular extension 13 into which projects one end of a supplementary exterior terminal 14 sealed through the glass forming the walls of the extension.

I find it extremely desirable, if not absolutely necessary, that the mercury should be introduced into the tube in as pure a condition as possible, and I find that this may be done by placing the mercury first within a vessel, not shown, communicating with the main tube 1 through a suitable passage as, for example, through the tubular extension 24, and then distilling the mercury into the main tube in vacuum. The extension may then be sealed ofl as shown. After the mercury has been introduced into the tube, the latter must be evacuated to as high a degree as possible, which is done by pumping, through the extension 15, and this pumping must be continued for a greater or less length of time after the lamp has been put into operation in order to withdraw all occluded or other gases which may be set free in the tube during the initial operation of the lamp. When gases are no longer given off, and the vacuum shows no signs of impairment, the connection between the tube and the pump may be sealed off.

In order to start the lamp on an ordinary direct current circuit, the main terminals 5, 10, are connected with a source of current in such a manner that the mercury electrode 3 shall be the cathode and the electrode 6 the anode. The supplemental electrode 11 is also connected to this source of current so as to form a supplemental anode. Resistances 16 and 17 may be connected respectively in series with the main and supplemental anodes to adjust the current flow.

These resistances also have a steadyin effect. The terminals of the lamp having en connected as described, the lamp may be started into operation by gently shaking the lower end of the lamp, which may be supported from its upper end by the ring 18 or some other suitable'arrangement. This act of shaking,-which in some instances may amount to no more than a delicate touching of the lamp, causes mercury to flow so as momentarily to connect the two electrodes 3 and 11, and, upon their disconnection, as the mercury recedes, gives rise to an are or discharge between the two bodies of mercury. The accompanying liberation of ions by the electrical vaporization of the mercury instantly causes current to flow between the main electrodes 3 and 6 of the lamp, which is thereupon filled with a brilliant whitish light. My present belief is that the action is a projection of ions which extends from the cathode toward or to the anode, and forms a conducting path and ultimately an arc, thus enabling the normal voltage of the lamp to initiate the flow of current between the main electrodes when such voltage, unassisted, would be incapable of doing so. It is certain that the initial opposition to the flow of the main current in the tube, if such a word as opposition may be used, is very considerable and has heretofore required the application of an electro-motive force of many hundreds of volts to the main electrodes of the tube in order so far to break down this initial opposition as to allow a moderate service electromotive force of the order, say of 100 volts, to set up and maintain the normal flow of current in the tube. Electrically vaporizing mercury within the v tube (va orization merely by heating would be ine ective because the vapor thus produced is non-conducting), or otherwise liberating free ions at the surface, gives rise to a conducting vapor which may be distinguished from the ordinary vapor of mercury by designating it as ionized vapor. This ionized vapor, being produced locally, spreads out through the tube, as I believe by a propulsion of its charged molecules along the static lines of force in the tube. The ions thus liberated by the vaporization of mercury at the surface of the main cathode 3 are therefore conveyed toward the main anode 6 and the whole time flashes into brilliance, the migration of ions from the main cathode usually reaching its normal rate instantaneously after the action has once been started up through the operation of the supplemental or auxiliary anode in the manner described.

It will be seen that while prior inventors have concentrated their efforts on devising means for conveniently generating electromotive forces high enough to forcibly break down from without the initial opposition of the tube, my invention, in the aspect I am now discussing, regardless of theory or nomenclature, is characterized by the fundamental distinction that I first weaken and, as it were, undermine this opposition to the flow of current so that I am then able to overcome it by service electro-motive forces if desired. The simplest way of practising my invention in its broadest aspect is to impress upon the main electrode of a tube in which the auxiliary electrode is either absent or inoperative a moderate electro-motive force, and then to shake the tube so as more or less violently to agitate or break up the surface of the mercury terminal, whereupon the opposition to flow of current will be so far reduced as to enable the electro-motive force impressed upon the terminals to start the lamp into operation.

In order to assist the flow of current between the main electrodes of a lamp of the character described, I have discovered that it is very advantageous to bring one of the electrodes, as for example the anode, within electrical proximity so to speak of the other electrode, and this may be done by extending from the anode a suitable electrical conductor such for example as a carbon filament or rod or a filament or rod formed of graphite or carborundum or of mixtures of these substances and clay, this rod having one end electrically connected to the anode and the other end extending toward the cathode but not into contact therewith. This rod it may be found necessary in many instances to support in a central position by means of a suitable anchoring device or devices. Such a structure I have represented in 'Fig. 2 in a lamp shown without its electrical connections. This lamp is similar in most respects to that shown in Fig. 1 but contains in addition the anode extension 19 in the form of a small filament of'material such as described. This filament is anchored by means of a ring or hook 20 supported by a hollow piece of glass 21 sealed through the wall of the main tube. This hollow glass body has a small opening 22 between the interior thereof and the tube, whereby when the main tube is exhausted the interior of the body may likewise be exhausted, thereby doing away with any danger to the vacuum of the tube should any accident such as cracking or the like occur to the glass body supporting the anchoring ring or hook 20. When the auxiliary arcing or starting device is put into operation, the conducting vapor proceeding from the main cathode 23 of the lamp seems, by the presence of the filament or rod 19, to be able more readily to reach the main anode than when no such rod or filament is used, the action being one in which the vapor, by reaching the projecting ends of'the filament, flows along quality until it reaches the anode. This ex-' tension of one of the lamp electrodes toward the other by an electric conducting medium is particularly useful in connection with relatively long tubes. I

I have set forth above that the auxiliary arc may be started by a manual agitation of the lower end of the tube which may, if desiredfbe provided with a knob 24.- to*serve as a hold for the fingers. Instead, however, of manual operation, I may employ electrical or electro-mechanical means, and such means I have disclosed and claimed in ap; plications filed concurrently herewith.

The supplemental or auxiliary anode, by the cooperation of which with the main cathode the secondary or starting arc is produced, may if desired be cut out of circuit after the lamp starts into operation, and for this purpose suitable automatic devices may be used, such as I have disclosed and claimed in other applications filed concurrently herewith. If, however, the supplementary or secondary are be maintained during normal operation of the tube, I find that there results the important advantage that in case the lamp for any reason has any tendency toward unstable operation, this is entirely prevented. Furthermore where the main arc alone would be stable within a very narrow range of current, the range of stability is materially increased by the presence of the secondary arc, making it possible to vary the main current. of the tube from a small minimum value up to the point where the current is. so great as to destroy the tube. By the use of an adjustable series resistance, the lamp may, so to speak, be turned up or down, or, in other words, its luminoslty increased ordiminished without departing from a condition, Since the lamp con-' of stable operation. sumes asubstantially constant voltage at its terminals at all currents, and since I have found by experiment that the ratio of the light to the energy consumed in the tube itself is within wide limits substantially independent of the current density, the efliciency of the lamp under these different conditions remains practically constant. Thus if the resistance in series with the lamp is doubled, the current is practically halved, the drop of potential across the resistance remaining practically the same as before,

and the efiiciency of the lamp the same as before or substantially so What'I claim as new and desire to secure by Letters Patent of the United States, is,

1. The method of starting an arc by applying an electromotive force to the electrodes between which the arc is to exist,

and then agitating one of the electrodes, which electrode is of a mobile character, so as to permit an ionic discharge to flow under the influence of the electromotive force mentioned.

2. The method of starting an are, which consists in applyin an electromotive force suitable for norma' o eration to the electrodes between which t e are is to exist, one of which electrodes is liquid, and then so agitating the liquid as to permit an ionic discharge to flow. under the influence of electromotive force mentioned.

3. The method of starting an are, which consists in applying an electr'o-motive force to the electrodes between which the arc is to exist, one of which electrodes is vaporizable, and then independently agitating the vaporizable electrode so as to cause an ionic discharge to flow under the influence of potential difference due to the electromotive force mentioned. a

4. The method of securing stable operation of an electric lamp of that type in which a vapor is maintained by the electric current in a luminescent condition, which of the main current of the lamp, which consists in supplementing said vapor by vapor produced by a stable source.

6. The method of securin a steady flow of current between electro es through a body of vapor, which consists in compensating for any tendency toward variation of resistance of said body ofvapor by causing a supplegnental generation of ionized vapor.

7. The method of securing stable operation of an arc from an electrode vaporizing at low temperature, which consists in maintaining a shorter auxiliary or steadying are springing from the same electrode.

8. The method of producing and controlling light, which consists in drawing an are from a main electrode, drawing a supplementa or steadying are from the said electro c and varying the opposition to current flow in the main arc.

In witness whereof I have hereunto set my hand this 24th day of February, 1902.

EZECHIEL WEINTRAUB.

Witnesses:

ALEX. F. MACDONALD, Hnmm Onronn.

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