US2445679A - Modulable electric discharge lamp - Google Patents

Description

E. LEMMERS IODUIQABLE ELECTRIC DISCHARGE LAIP July 20, 1948.

Original Filed Feb. 12, '1942 EUGf/VE L'EMMERS H5 Arm/z/vi explained.

Patented July 20; 1948 FFICE 2.445.010 Mon'ULAnu: anac'rmc mscna'ma Lam Eugene Lemmers. Cleveland Heights, Ohio, u-

Ilmor to General ration of New York Original application Feb Divided and this Serial No. 551,793

No. 430,598. at 30, 19,

eotrio Company, a co f 12, 1942; Serial application An- -1 cum. (c1; 176,-122) This invention relates to the'modulation of an ectric discharge, and is especially concerned known as crater lamps."

is application is a division of my application Serial No. 430,593, filed February 12, 1942, in which is described and claimed lamps of the positive column type, whereas the lamps specifically disclosed and claimed in this application are of the well known negative glow type.

Various arrangements and constructions may be employed, several of which will be illustrated and Still other features and advantages oi the invention will appear from the following description of species and forms of embodiment, and from the drawings.

In the drawing, Fig. g-rammatic view of a lamp comprising my invencircuit,-

through a power circuit H, the the amplifier output circuit i2.

As shown in amplifier T, and

electrode 23 extends inside the flange of the anode structure.

f r-s tive in the sense outside the envelope 20, and also a portion of the circuit il.

In operation, the discharge current in the lamp L is proportional to the signal intensity from S. The intensity of the endwise radiation from the discharge toward the receiving system R depends on the discharge current. In the absence of the anode means 23 with its connection 25, the intensity of the discharge would vary in sole dependence of the discharge current. However, the resistance 26 in the connection 25 makes the part 23 an anodeof lower'potential relative to the cathode is than the main anode i6, so that part of the discharge goes to this part 23, diminishing its end-on intensity of radiation. The degree to which this takes place depends on the magnitude of the resistance 26 in the connection 25, as well as on the position of the part 23. If the eflective resistance 26 were zero, all the discharge would go to the part 23; if it were infinite, or, virtuallyso. all the discharge would go to the main anode IS. The positive potential of the part 23 relative to the discharge within it depends, of course, on the value of the resistance 26, and can be increased by reducing this resistance, and vice versa. I

Whatever the value of the resistance 26, the effect of the part 23 and the connection 25 on the current-light curve of the device is subtracthat the light for a given discharge current flowing in the circuit I1 is reduced. Naturally, this effect is proportionally greater for low currents, since the smaller the current flow, the greater'the proportion of it that can be accommodated by the path via the part 23 and the resistance 26, which gives rise to a lower intensit of radiation than an equal current via the main anode i6. Accordingly, .the lower end of the current-light curve is depressed very greatly in proportion to its height above zero, while the upper end affected. Thus the connection 25 with its resistance 26 makes the end-on intensity of radiation toward the receiving system It vary in a greater ratio than the discharge current, and this ratio can be altered by adjusting the resistance 26.

Fig. 2 illustrates diagrammatically a somewhat different type of crater lamp oi! the negative glow type also embodying the invention. Here the cathode 15a consists of a hollowed cylindrical metal body enclosed in an insulative sleeve ll with an internal flange 42 covering one end of the body i5a around the mouth of its exposed of this curve is scarcely major cathode hole 40a. The mouth of a minor cathode hole 43 in the other end of the body is also exposed. The main anode i6a has the form of a sheet metal-cap over and around the flanged end of the insulator 4|, centrally apertured in axial alignment with the major hole 40a, while the other anode 23a has the form of a sheet metal cap over and around the other end of the insulator 4| and cathode lid, with a central metal boss 45 projecting into the minor hole 43. The circuit connections are essentially the same as shown in Fig. l, and are marked with the same reference characters, as a means of dispensing with repetitive description.

The embodiment of applicants invention shown in Fig. 2 is being claimed in copending patent application Serial No. 787,117, filed November 20, 1947, and which is assigned to the assignee of this application,

What I claim as new Letters Patent of the United States is:

A modulable gaseous electric discharge lamp of the negative glow type comprising a sealed envelope containing an ionizable medium, a hollow cathode having an internally electron emissive bore, an annular sheet metal anode in front of said cathode and aligned axially with said bore and having a flange extending toward said cathode, and a shell-shaped sheet metal control electrode closely surrounding and enclosing the sides and back end of said cathode. and extending inside said flange.

EUGENE LEMMERS.

REFERENCES CITED UNITED STATES PATENTS Number Name Date 1,834,072 Schroter "Dec. 1, 1931 1,834,251 Moore Dec. 1, 1931 1,912,097 Rinia May 30, 1933 1,915,934 Holst June 27. 1933 1,923,051 Case (a) Aug. 15, 1933 1,932,078 Knowles Oct. 24, 1933 1,951,143 Foulke Mar. 13, 1934 1,951,808 Smith Mar. 20, 1934 1,970,223 Case (b) Aug. 14, 1934 1,999,649 Brett Apr. 30, 1935 2,055,753 Schnitzeler Sept. 29, 1936 2,190,303 Blackburn Feb. 13, 1940 and desire to secure by

Images