US2457787A - Potential divider - Google Patents

Description

Dec. 28, 1948. J. A. STAGNARO 2,457,787

POTENTIAL DIVIDER 3 Filed June 2, 1944 4o :lll l lk- 2s 21 2a 29 k .A. .A .Lm..J.

Y'V' rIII" I"! Y" II" III I." "II IVY "I" INVENTOR JOHN A. STAGNARO ATT RNEY Patented Dec. 28, 1948 UNI TED .S OF Fl C E.

, .2,457,7sr. TO'I EN'HAL urvmER John A. .Stagnano, Fort Wayne, ImL, :assig-nor,xby mesne assignments, to Farns-worthW-Research Corporation, a corporation of Indiana Applicationlune 2; 1944, Serial No.*538 ,499

5 Claims. (Cl.-,250-17.5

'This invention relates to electron multipliers and is particularly directedito multistage multi pliers wherein, there is provided asfa'n integral part thereof a potential dividenfor providing, .erating potentials.

It .is known-in the art that electron-multiplier tubes generally comprise an electron-emitting cathode and a collector anode. Arranged. serially between the cathode andanode is a plurality of electrodes having high secondary electron-eminision properties. For accelerating the electron emission from each electrode a succ'ess'ively increasing positive potential must be applied'thereto. It has been customary to derive the respecfi potentials from a voltage source'bymeans of resistors. It'ischaract'eristic of present-day elec. tron multipliers that no two are exactly alike with respect to inter-stage operatingpotentials; Consequently, it is necessary *thateach individual tube beprovi'ded with its individual potential di- 'vider 'consistingof aplura-lity of resistors, each resistor being designed to provide the'properopera-ting potential between a certain pair of multiplier stages. Heretofore it has been the practice to dispose the resistors at random within a .tubechaesis withmespeeti-nedeads therefrom being connected to the electrodes pf the tube. Periodically, because of tube .failure and the like, replacement of the electron multiplier is necessary. each multiplier are different, it isfnecessary',upo'n the replacement of a tube towchange one or more of'theresistors to coincide "with the characteristics of the new tube. This entails removal -of old resistors and redfesignof circuits andcauses undue. loss of operating time invaluable :app'aratus.

Hence, it is the principal objector thisinvention to provide as an integral'part of an elect-ron multiplier a potential divider consisting of a plurality of resistors, each of which'is matched to the multiplier. 1 "In accordance with: the present invention there is provided a multistage multiplier including an envelope having arranged therein a plurality of multiplier components, each component having individual characteristics. Connected to the multiplier components is a potential divider having components matched with respect to the characteristics of the multiplier components. There are also provided means for connecting the potential divider with the multiplier and means for securing the divider to the envelope t of the multiplier.

For a better understanding of the invention,

Since the electrical characteristicswof flit) din together with other andtiurther objects thereof, reference-.zis made to. the following description, taken ine connection with the accompanying drawing. :and its *scope will .be pointed. out-in the appended claims.

.In- :the L accompanying drawing;

Fig. 1 .is 'a sectionalrview of the device in operative relation *with a: .dissector' tube having mounted therein a multistage multiplier;

:Eig.x2-is= alsectional view of the device taken linear-21 cm Fig. 1;..and.

:E'igJB i is a schematic wiring diagram showing accirenit includingavpotential divider connected to the'vari-ous stagesntthe multiplier.

Reierringmarticularl-y to Figs. 1 and 2 of the 'drawingithererisrshown a dissector tube I having .anaevacuatedxenvelope .2. Mounted at one end oi rthe tube there is a "photosensitive electroncathn'de 73. .Disposedadjacent the op posite end thereof in the rneck vportion' l of the envelopeithere is-mounted a multiplier :5 having aiiplura lityof serially arranged box-like electrodes suchtaszzt, 1i, :8: and 9. Adjacent the electrode?) islthe collecting anode I50.

fMounted'onrth-e neck portiont of the tube is arnnitary electrical.potentialudivider II. This homprisesia cylindricalcontainer I2 having a lowerend wall I'll, in'whic'h is centrally disposed an aperture I4. Secured to't'he wall l3"by screws or other suitable fastening means and extending "outwardly therefrom, in direct alignment with "theaperture M, is flanged tube 20. Disposedflwithin the inner Wall of the tube is a resilient member! 6 whichiis adapted to frictionallyengage the neck portion 4 of the tube to securelyfholtl"the'device in operative position.

'S'ecured 1 ]oy=screws 'l5 and 3 l1 within the container f z and againstthe wall-f3 thereof, there is arranged a pairfof annular insulator members l a an-d I Si Mdunted-on the member I 9, by screws 22, 23 and-"2331s -an-'=annuiar insulator plate 25 on -wvhich isflm'ounted a plurality of resistor-elemerits such as -7233.21, 28" and29haying electrical characteristics which match those of the multiplier whereby to provide the desired electron acceleration and secondary emission. Each of the resistors is mounted on a pair of studs 30 and 3| which are secured to the plate 25. Secured t0 the inner wall of the container H there is arranged a plurality of lugs such as 32 and 33, which are adapted to securely fasten the cover 34 at the open end of the device. Disposed in the inner side of the cover, there is provided an insulator plate 35.

On the wall of the container ll there is pro- 3 vided a pair of openings 36 and 31 through which may be passed the output conductors leading from the tube to whatever auxiliary apparatus may be required.

Referring to Fig. 3 of the drawing, there is shown the electrical connections of the device in operative relation with the various stages of the multiplier. The resistor element comprises series connected resistors 26, 21, 28 and 29, across the end terminals of which is connected a relatively high source of potential, such as a battery 40. Between each resistor is a tap, each tap being connected to the respective stages of the multiplier. From this arrangement there is impressed upon each succeeding stage of the multiplier an increasingly higher positive voltage.

In accordance with the object of this invention,

there is provided a potential divider which is designed, constructed and passed on to the user as an integral and permanently attached part of each individual multiplier tube. Each of the resistors in the divider are chosen because of the particular individual requirements of the successive multiplier stages. As stated hereinbefore, it is impossible to manufacture multiplier tubes wherein the characteristics of the multiplier stages are identical in all respects. Thus it will be obvious to those skilled in the art that each tube requires an individually-designed potential divider. Prior to this invention, replacement of an electron-multiplier tube in a given circuit required redesign of the potential source, but since applicant provides as a permanently attached part of the tube a potential divider matched to the electrical characteristics of that tube, replacement of the tube will only require removal of a defective tube and insertion of a new tube in the tube socket. No alteration of the permanent circuit which forms a part of the tube chassis will be necessary.

While'there has been described what is at present considered the preferred embodiment of the invention, it will be obvious to those skilled in the art that various changes and modifications may be made therein without departing from the invention, and it is, therefore, aimed in the appended claims to cover all such changes and modifications as fall within the true spirit and scope of the invention.

What is claimed is:

1. An electron tube assembly comprising an envelope containing therein an electron multiplier, and a potential divider permanently mounted on said envelope adjacent said multiplier and having electrical characteristics matched to those of said multiplier, said divider comprising a plurality of series-connected resistors, each of which is matched with and connected to one or more stages of said multiplier.

2. An electron tube assembly comprising an envelope containing therein an electron multiplier, and a potential divider permanently mounted on said envelope adjacent said multi- 4 plier and having electrical characteristics matched to those of said multiplier, said divider comprising a plurality of series-connected resistors, each of which is matched with and connected to one or more stages of said multiplier, a supporting means for said divider comprising a cylindrical body portion, a neck portion fixed thereto and to said envelope and an insulating disc Within said cylindrical portion supporting said resistors.

3. An electron tube assembly comprising an envelope containing therein an electron multiplier, and a potential divider permanently mounted on the outside of said envelope and having fixed electrical characteristics matched to those of said multiplier, said divider comprising a plurality of series-connected resistors, each of which is matched with and connected to one or more stages of said multiplier, a resistor-supporting means comprising a container, an extension fixed thereto and to said envelope and an insulating member fixed within said container supporting said resistors.

4. An electron tube including a neck portion having mounted therein a multistage multiplier, a cylindrical container having at one end thereof a wall with a centrally-disposed aperture, a flanged cylindrical support secured to said wall and extending outwardly therefrom, a resilient member mounted adjacent the inner wall of said support frictionally engaging the neck of the tube, an insulating plate secured to said wall and having a centrally-disposed aperture and a plurality of resistors arranged symmetrically on said plate and connected to said multiplier.

5. An electron tube including a neck portion having'mounted therein a multistage multiplier, a cylindrical container, a support secured to said container adapted to engage the neck of the tube and an insulator plate secured to said container having a plurality of resistors connected to said multiplier.

JOHN A. STAGNARO.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,699,011 Murphy Jan. 15, 1929 1,923,552 Murphy Aug. 22. 1933 1,981,115 Murphy Nov. 20, 1934 2,051,693 Finch Aug. 18, 1936 2,078,304 Zworykin et a1 Apr. 27, 1937 r 2,252,752 Bliss Aug. 19, 1941 2,257,942 Farnsworth Oct. 7, 1941 2,264,630 Farnsworth Dec. 2, 1941 2,315,288 Knoop Mar. 30, 1943 FOREIGN PATENTS Number Country Date 478,262 Great Britain Apr. 13, 1937

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