US1951156A - Gaseous electric discharge device - Google Patents

Description

March 13, 1934. H. LEMS 1 6 GASEOUS ELECTRIC DISCHARGE DEVICE Filed Aug. 17, 1932 INVENTOR 95 m BY buzz.

ATTORNI-IZY Patented Mar. 13, I 1934 1.951.150 GASEOUS ELECTRIC mscmaon navrca I Hendrik Lems, Eindhoven, Netherlands, assignmto General Electric Company, a corporation of New York Application August 17, 1932, Serial No. 629,204

In Germany August 19, 1931 '4 Claims. (01. 176-124) The present invention relates to gaseous electric discharge devices generally and more particularly the invention relates to methods and means for starting and operatingsuch' devices equipped with auxiliary electrodes.

It is well known in the art that the starting potential of a gaseous electric discharge device is higher than the operating potential thereof and that the absolute starting potential is in most cases extremely high particularly in those devices having a long positive column. The object of the present invention is to decrease the starting potential of gaseous electric discharge devices. Another object of the invention is to start and operate on a determined potential gaseous electric discharge devices having a longer discharge path than has hitherto been found practicable on such potential. Still further objects and advantages attaching to the device and to its use and operation will be apparent to those skilled in the art from the following particular descriptionand from the appended claims.

The invention attains its objects by providing one or more pairs of auxiliary electrodes in the container of the electric discharge device. Said auxiliary electrodes are in close proximity to the main discharge supporting electrodes, extend along the longitudinal axis of the container of the device, are connected through an impedance to an auxiliary current source of a higher potential than the current source to which the main discharge supporting electrodes are connected and each is of the opposite polarity with respect to the main electrode to which it is adjacent.

In the drawing accompanying and forming part of this specification two embodiments of the invention are shown, in which Fig. l is a schematic view of one embodiment of the new and novel electric discharge device and a circuit therefor, and

Fig. 2 is a similar view of another embodiment of the new and novel gaseous electric discharge device.

Like numbers denote like parts in both the figures.

Referring to Fig. 1 the gaseous electric discharge device illustrated has a container 1.

I Said container 1 has electrode chambers 2 and 3 and thermionic electrodes 4 and 5 are sealed into stems 6 and '7 of said chambers 2 and 3 respectively. Said electrodes 4 and 5 consist of a coiled wire, such as tungsten wire. coated with an electron emissive material as an oxide of an alkali earth, such as barium oxide. Two auxiliary electrodes 8 and 9 are sealed into said stems 6 and '7 respectively and extend along the axis of said container 1. Said electrodes 8 and 9 are physically connected by a body of insulation material such as a glass bead 10. Said container 1 is filled with an electric discharge conducting gaseous atmosphere such as a rare gas, a common gas or a metal vapor or a mixture of these such as a mixture of argon and mercury.

The auxiliary electrodes are connected through resistances 11 and 12 respectively to the secondary coil 13 of the transformer 14. The mid-point of the primary 15 of said transformer 14 is connected to the mid-point of said secondary 13, as shown. The transformer 14 is connected to the terminals of an alternating current source 16 of 110 or 220 volts. The thermionic electrodes 4 and 5, which are the main discharge supporting electrodes, are connected to the secondaries 1'? and 18 respectively of the step-down transformer 17, 18,- 24. The primary coil 24 of said stepdown transformer is connected to the terminals of said current source 16 to furnish the heating current for said electrodes 4 and 5. The operating potential is supplied to the electric discharge device by leads l9 and 20 connected to the terminals of said current source 16 and to the mid-points of said secondary coils 1'7 and 18 respectively. An impedance 21 is connected into one of said leads 19 and 20' in series with the discharge path.

The transformer 14 is so designed that the potential from the secondary coil 13 is higher than that of the current source 16. The connections are such that when main electrode 4, for example, is negative the auxiliary electrode-8 is positive. The higher potential supplied by the secondary coil 13 causes the potential between the auxiliary electrodesB and 9 to increase more rapidly than the potential between said main electrodes 4 and 5. Thus a glow discharge takes. place between the adjacent ends of said auxiliary electrodes 8 and 9 and an arc discharge takes place between said auxiliary electrodes 8 and 9 and said main electrodes 4 and 5 respectively which quickly and heavily ionizes the gaseous filling in the discharge path between said main electrodes 4 and 5 to facilitate the starting of the positive column discharge in said device.

The current flow in said secondary coil 13 and the auxiliary electrodes 8 and 9 is comparatively small due to resistances 11 and 12 connected into the circuit thereof. The value of said resistances 11 and 12 is from 1,000 to 10,000 ohms, as desired. and said resistances are replaced by a. choke-coil or a condenser where desired. The 110 its "transformer 14 is accordingly of very small size.

An electric discharge device having a container 1 m. in" length, 40 in diameter, filled with neon at 1.8 mm. pressure and having the structure above described and connected tothe above described circuit is started into operation by' a potential of 180 to 190 volts. The potential of the secondary coil 13 is then 360 volts.

The gaseous electric discharge device illustrated in Fig. 2 is similar to that shown in Fig. l with the exception that in this embodiment the electrodes Sand 9 are covered at those parts thereof adjaeent the main discharge supporting electrodes 4 and 5 with'a body ofinsulation ma terial such as a porcelain tube to preveritthe spattering of material from said electrodes 8 and 9. The'parts of said electrodes 8 and 9 adjacent eachjother are surrounded be a metal grid or net 23 which is supported by the inner wall of said container 1. Said net 23 intercepts the spattered particles from the adjacent and parts of said electrodes .8 and 9 to prevent said particles from depositing on the wall of said container 1 so that; the transmission of the light rays through said container 1 is not effected by said spa'tterecl particles. 7

The starting and operating characteristics of the device illustrated in Fig. 2 when connected to the circuit described in connection with Fig. 1* i; the same as those of the device illustrated in While I have shown and described and have pointed out in the annexed claims certain novel features of the invention, it will be understood that various omissions, substitutions and changes in the forms and details of the device illustrated and in its use and operation may be made by those skilled in the art without departing from the broad spirit and scope of the invention.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. In combination, an electric discharge device comprising a container, electrodes sealed therein, a gaseous atmosphere therein, at least two of said electrodes being main discharge supporting electrodes connected to the terminals of an alternating-current source, two other of said electrodes extending along the discharge path between said main electrodes each being adjacent one of said main electrodes, each of said auxiliary electrodes being connected through an impedance to a terminal of a current source of higher potential than that to which said main discharge supporting electrodes are connected.

being connected through an impedance to a terminal of acurrent source of higher potential than that to which said maindischarge supporting electrodes are connected, the main discharge supporting electrodes and the auxiliary electrodes adjacenteach other having opposite polarity.

13. In combination, an electric discharge device comprising a container, electrodes sealed therein, a gaseous atmosphere therein, at least two of said electrodes being main discharge supporting electrodes connected to the terminals of an alternating-current source, two other of said electrodes extending along the discharge path between said main electrodes each being adja- "cent one of said main electrodes, each oi. said auxiliary electrodes being connected through an impedance to a terminal of a current source of higher potential than that to which said main discharge supporting electrodes are connected, the main discharge supportingelectrods and the auxiliary electrodes adjacent each other having opposite polarity, the parts of said auxiliary electrodesadjacent said main electrodes being covered with an insulation material.

4. In combination, an electric discharge device comprising a container, electrodes sealed therein, a gaseous atmosphere therein, at least two of said electrodes being main discharge supporting electrodes connected to the terminals of an alternating-current source, two other of said electrodes extending along the discharge'path between said main electrodes each being adjacent one of said main electrodes,'each of said auxiliary electrodes being connected through an impedance to a terminal of a current source of higher potential than that to which said main discharge supporting electrodes are connected, the main discharge supporting electrodes and the auxiliary electrodes adjacent each other having opposite polarity, the adjacent parts ofsaid auxiliary electrodes being surrounded by a grid supported by the inner wall of said container.

RIK LEMs.

me I

Images