US1526191A

US1526191A - Variable high resistance

Info

Publication number: US1526191A
Application number: US574474A
Authority: US
Inventors: Charles E Vawter
Original assignee: Individual
Current assignee: Individual
Priority date: 1922-07-12
Filing date: 1922-07-12
Publication date: 1925-02-10
Anticipated expiration: 1942-02-10

Description

Feb, 10,1925. 1,526,191

c. E. vAwTER VARIABLE HIGH "RESISTANCE Filed July 12, 1922 INVENTOR BY z E .g TTORNE Patented Feb. 1o, 1925.

CHARLES E. VAWTER, OF PHILADELPHIA, PENNSYLVANIA.

VARIABLE HIGH RESISTANCE.'

Application led July 12',

To all whom it may concern:

Be it known that I, CHARLES E. VAwTEn. a citizen ot the United States, residing at Philadelphia` in the county ot Philadelphia. State of Pennsylvanim'have invented certain new and useful- Improvemcnts in Variable High Resistauces: and I do hereby declare the following to be a full., clear, and exact description of the invention, sueh'as will enable others skilled in the art to which it appertains to make and use the' saine.

This invention relates tovaiiable resistances, and more particularly to variable high resistances especially adapted to bcused as grid leaksand for other purposes in connection with rad-io systems.`

lIn operating radio systems it has been ound.-v necessary to provide lsomcmeans whereby the negative charge which 'accumulates on the grid 'of the vacuum tube may -be dissipated. It vacuum tubes are used without a suitable grid leak, the operation is not always satisfactory due to the choking effect of the negative charge which accumulates on .the grid.

One of the bestways of carrying off the negative charge of the grid is to provide a high resistance in the grid circuit. A high resistance suitable for this purpose should bc easily adjustable. and its character should be such that when it is once adjusted the resistance does not vary.y The effect of the high resistance is to provide a means whereby the negative charge o the grid may'bc dissipated at a definite rate., vThe Value of resistance required in any given case de'-l pends upon various factors, such as .the character or" the vacuum tube employed, the voltage impressed on the vacuum tubev` the current in the filament and the degree of vacuum. The resistance'serves not only as a lready means for dissipating the negative charge, but also as a means for greatly increasing thc utility of the vacuum tube.

One of the objects ot this invention is to provide a high resistance which may be easily adjusted, the resistance being of. such a character that When it is adjusted to any given value it remains constant at that value. A further object is to provide an .inexpensive variable high resistance which possesses qualities superior to those of any other high resistance.

Another object is to provide a variable high resistance unit of an improved..con struction, such that theresistance unit may 1922. Serial No. 574,474.

be readily attached to the terminals of a grid condenser, thus providing a combined condenser and grid leak of improved construction and characteristics.

T hc means by which the above mentioned objects and various others are attained will .be apparent from the following detailed. description which is to bc taken in conjunction with the accompanying drawings in which-A Fig. 1 is a top plan View of the improved resistance unit showing the manner in which it is attached to a condenser;

Fig. 2 is a longitudinal section taken on line 2-2 of Fig. 1 showing the construction of the resistance unit and of the condenseri Fig. 3 is an enlarged transverse section taken on line 3 3 of Fig. 1 showing the details of construction.

Fig. 5 is an end elevation of the structure shown 1n Fig. 4.

Referring to the drawings, and more particularly to Figs. 1 to 8, it will be noted that the improved resistance unit comprises primarily a container 1, which in the form shown consists of a tube of insulating mae terial. This tube 1 may be made of glass. or ot any other suitable insulating material. The inside of they tube 1-is filled with a suitable paste material which constitutes the resistance element ol the unit. This paste 2 may be composed of finely divided carbon mixed with tallow, or it may be made of other suitable materials. For example, potassium bichromate may be substituted for the carbon. In fact, any substance nfay be used which is of a semi-huid nature and possesses a low electr-ical conductivity which does not vary when the resistance vof the unit is adjusted to any given value. y

lIDlectrical contact is made with the paste 2 by means of two

metallic end pieces

3 and 3. which, as shown in the drawing, are

adapted to enclose the ends of the tube 1.

These, endpieces may have extensions 4 provided thereon by means of which the resistance unit` may be mounted on any suitable base. One of the. end pieces, for example,

the end piece designated as 3 is provided with a small hole 5 concentric with the inf.v`

Plunge tube l.

The resistance 'of the unit. maybe considered as composed ot two. Components.

One,eomponentis the resistance of that dorf tion of the paste which is not penetratec by `the pin 65 and the 'other oomponentis the resistance of the remainingv portion of the -unit comprising that portion of the pin within .the tube l, and the paste surroundfing that portion of the pin. It is evident does contain 'the metallie pin 6.

that. the' resistance of that'portion of the tube which does not contain the pin is higher than the remaining portion Whirh It is thus 'apparent that the resistance of the tube may be varied hy changing the. position of the pin 6." For example, when the pin 6 is'moved to the dotted position' shown .in Fig'. 2, the resistance of the unit is increased, due to the decrease in length of that portion of the pin which is Within the tube 1.'

` 'The resistance unit shown in Fig. comprises atuhe l containing a high resistance paste similar tothat in the tubol of the unit shown in Figs. 1 3.- The tuhe l is preferably made of fiber or other insulating material, and has metalen/d pieces 1.3 and 1B. These end pieces i3 and 13" are adapted to he slipped over ther ends ot the tube 1"With a pressed vtit, the tube l being first iled with the' paste 2. One of the end pieces7 for example, 13 has a smaii hole or passage 14 in the end thereof.

The resistance unit shown in Figje is ot the cartridge type and may he made ot standard size to fit any ordinary grid leak sockets or receptacles such as shown at 4i. The'unit-may hev used as a fixed. high resistance, or it may be used as a variahie re sistance.' When used as a fixed resistance the opening or passage 14 is 'preferably sealed. When the unit is used ".f a Variable resistance, a needle 6a. simila-r'totlie needle 6 of Figs. 1-3 mayhe used, the resistance being varied h'y varyingth'e'position oi" the needle. I

I have found that a variable resistance ConstiiciedI ,mi the mannen@ l'described here possesses 'qualitiess'iipe-rior to those ot any other typeo vaniablerhigzh resistance. The resistanceot the runit/maybe easily adjusted to any desiredyaliie and 'when the' resistance hasgheen adjusted Ito any given value.

'it remains oolistantjfhe construction of Vthe resistance unit-isjvery.-,simpie and, theretore. resistanees otthisstype may oe made in large quantities at yery low cost. Each of .the eonponentfpafrts. ot `the resistance unit is easy to manufacture. `For example. the' tubeconsists merelyof 'a short length ot ordinary tubingt of anxr suitahleAo-haraeter, such as gia-eser Aber `lterminais proyunit shown"fin1f,Figs. i to 3.

maaier 'only ordinary skill is required to the elements in any desired proportions.

The improved resistance unit may he made ot suoli dimensmns that it may be readily attarlied to the terminals of a. condenser.

inthe-Combined condenser and resistance the improved variable resistance shown attached to the terminals ot an improred condenser, the condenser heilig m the ti'pe disclosed 1n InyopendingY appliration. .Qerial No. 562.963, r'iledA May i3. 1922.

As described inmi eooendinn' ap ilieation.

the improved eondcnser comprise. piumiity of armatures S separated hf: thin strips of dieieetrir materia-l. The armatures and strips oi' dieieetrio material are enclosed-in a metal casing; 9. the sides or" which are pressed. to clamp the armatures in position Tabs i() are provided at thoends.

ti fghti y. oi the armatures S. the tahs heine' connected so that they form the terminals ot the condenser. In the form shown in thedrawing.

the condenser comprises two armatures oniy.

A strip lfi ot halteiie or other suitable in srdfitinef material is provided between the extensions Liandr of the resistance terminais. and the lcondenser terminais, the purpose ot' this insulating; material being to prevent eleetricai Contact` between the con denser casingy and the resistance element. The several eiements ot the composite unit are Nfastened together hy any suitable means, surh as .the holte 12. The boit-s 'i2 aise serve as a means tor connecting the improved unit-q inroirouit with the other elements of the grid circuit.

From the shove description it shouid he 'apparent that the present' invention provides an improved vnriahie hie/h resistance element which partieniarly adapted to he usedV in connection with n'ireiess systems. The, improved resistance is partieniariy adapted 'to he used as aerid ieak. and as a 'variable hie'h resistance shunt 'for ny-passing oliject-i'onahie high .frequency or momentary current-s.

' it willho nn'derstod that the'invention is not limited to the particular"emhodiments .shown and described. init is intended to in! olude suoli niodinaiiions thereof as tali within the scope of the' appended claims; and the proportion'sotthe `arious parte and the materiais ofwvhieh" they are made may he varied Wit-hout departing rointhe scope of the inn ntion .as defined in 'the appended ciaiinsL 4 Y Y i x i daim, f 1. A. variable resistance nniteomprisin'g a .container. a resistancemateriai Within 'so' i ino anti arranged at the reepeeseid ntainer for transmitting enr-rent to and Sinin said resistance ina.'- eieel, en electrically conducting member .eliclnnlg' mounted in one of Said oonclneting terminals :incl extending Within said con# tainer inte electrically conducting relation with-the resistance materiel therein, whereby said member is adjestablev longitudinally of eziicl Container te. @ense ifnrying preportione said resistance ineteriei to be traversed by the eleetrie current passing between the tern'iinale ef the unit.

i vnrinlile resistance unit comprising a tnbnler cent-einer, resistance materiel Wieliin said eontaiiier, conducting termin-ile at ille respective enfle of said container -ler .nsmitting enrrent to end from Seid re- ',tenee materia-l, an electrically eonclnoting nien sliclably mounted for longitudinal movement in the enel of one of said een-I .neing tesininels and exteinlinf into eleo- 'ieailg'eondneting relation with the resistneegnmteriei Within the container to thereupporte r-saicl container, said supports y very the resistance of the unit upon albeing adapted to engage the ends ef eei Container :incl one of said supports having a, hole for the passage of seid adjustable member. l -Y 3. A variable resistance 'unit comprising container, a resistance materiel Within said eontainer, conducting terminals et the respective ends of said container' for transmitting onrrent to and from said resistance material, the said respective conducting terminals lia-ving tapered extremities, en. electrically conducting member assing through one of said conducting terminals at substantially the apex of the tapered portion thereof and extending Within Said container into electrically Conducting relation with the resistance material therein, whereby said nienilier is slidable longitudinally of said container to cause varying proportions of said resistance material to be traversed by the electric current passing between the terminals of the unit, and conducting Supports for said container having apertures for receiving the tapered ends of said eontainer7 and permitting the passage of said conducting member.

In testimony whereof I aiiix my signature.

CHARLES E. VAWTER.