US2031846A

US2031846A - Electric oscillation circuit

Info

Publication number: US2031846A
Application number: US445599A
Authority: US
Inventors: Muth Herbert
Original assignee: Telefunken AG
Current assignee: Telefunken AG
Priority date: 1929-05-24
Filing date: 1930-04-19
Publication date: 1936-02-25
Anticipated expiration: 1953-02-25

Description

Feb. 25, 1936. H, MUTH ELECTRIC OSCILLATION CIRCUIT Filed April 19. 1930 BY 1 INVENTOR E M5/W ATTORNEY Patented Feb. 25, 1936 UNITED STATES PATENT OFFICE 2,031,846- ELECTRIC OSCIILATION CIRCUIT Herbert Muth, Berlin, Germany, assignor to Telefunken Gesellschaft fur Drahtlose Telegraphie m. b. H., Berlin Germany, a corporation of Germany Application April 19, 1930, Serial No. 445,599 In Germany May 24, 1929 13 Claims. (Cl. Z50-40) form (deformations) as due to the thermal co` eiiicient of expansion of the materials used in the presence of heat variations, are required. Now, in order that these changes in form may be kept inside small limits, only materials possessing an extremely small coeiilcient of thermal expansion are used. In viewv of the fact that metal alloys having a small heat expansion coefilclent (such as Invar) are difllcult to work so into the desired form and when so worked often are subject to internal strains which affect their operativeness, recourse is had according to this invention to the use of insulators or non-conductors possessing a low temperature coeiilcient, such as fused quartz, porcelain, or steatite which are covered externally with ametallic coatso that their surfaceisrenderedconductive. Materialssuitable for covering the non-conductor are copper and silver, because of their high conducting power. In a preferred form the copper or silver coated nonconductor may be given an additional coating of gold or platinum in order to protect the conducting film from atmospheric effects. The said coatings may be applied by any desired method, say, ceramically or electrolytically, or by both these processes. The requisite thickness of the film is governed by the frequencies to be used since it depends upon the depth of penetration of the alternating current into the material in question. For high frequencies it need not be over a few hundrdths of one millimeter thick.

The manner in which the present invention is carried out will be readily apparent from the following description of a specific embodiment of the same. In the drawing:

Fig. 1 is a diagrammatic view of an oscillation circuit partly in section; and

Fig. 2 is a cross-sectional view of the conductors used in the circuit of Fig. 1, the proportions being exaggerated for the sake of clarity. Referring in detail to the drawing the leads I3 and coil I0 comprise a non-conducting core II and a conducting coating I2 applied thereto as shown in Fig. 2. The leads Il of the same structure as the coil I0 connect the coil to a condenser I 4. I'he condenser I4 is made up of non-conducting plates I5 coated by the conducting material I2. Any suitable leads I6 may connect the oscillation circuit to the apparatus with which it is to be used.

Having thus described my invention, I claim:

l. A radio frequency relay circuit the conductors inductance and condenser plates of which are composed of a hard, solid non-conducting material, a continuous layer of conducting ma- 10 terial on said non-conducting material, and a continuous layer of chemically inactive conductive material on said last named layer of conducting material.

2. An oscillation circuit the capacitive and in- 15 ductlve elements of which are of a solid, nonconducting and hard base material, a continuous layer of copper superposed on said non-conducting base material, and a continuous layer of gold over said layer of copper. 2

3. An oscillation circuit including a tuning capacity, said capacity being composed of physically separated plates of non-conducting material, a layer of conducting material over said non-conducting material, and a layer of chemically inactive conducting material over said first named layer of conducting material.

4. An oscillation circuit including an inductance coil comprised of a base of non-conducting material'possessing a relatively low temperature 30 coenicient as compared with metals such as copper, and a continuous layer of conducting material superposed upon said base, in parallel relationship with a condenser comprised of two physically separated non-conducting plates of quartz 35 having superposed thereon highly conducting material such as copper or silver.

5. An oscillation circuit comprising an inductance having a single continuous core of solid non-conducting material, a continuous layer of 40 conducting material superposed on and fixed to` said core, and a layer of chemically inactive conducting material over said first mentioned layer of conducting material.

6. An oscillation circuit comprising an in- 5 ductance having a single continuous helical core of solid non-conducting material, a thin continuous layer of conducting material superposed on and fixed to said helical core, and a layer of chemically inactive conducting material over said 50 first mentioned layer of conducting material.

' 7. An oscillation circuit comprising an inductance having a single continuous helical core ,y of solid non-conducting material, a condenser Vcomprising two physically separated non-conducting platea'a thin continuous layer of metal surrounding said helical core and said non-conducting plates, and conductive means for connecting in parallel relationship said inductance and said condenser.

8. .An oscillation circuit comprising an inductance having a single continuous helical core of solid non-conducting material, a condenser comprising two physically separated non-conducting plates, a thin continuous layer of metal surrounding said helical core and said non-conducting plates, a, plurality of rod-like members having a similar metallic coating as said inductance and said condenser for connecting in parallel relationship said inductance and said condenser. g

9. An inductor comprising a conductor disposed in a coil of at least one turn, said conductor having a core of material having a low coefcient of thermal expansion xed to a shell of conducting material having a high electrical conductivity and a relatively high coefficient of expansion.

10. An inductor comprising a conductor disposed in a coil of at least one turn, said conductor having a core of relatively low coemcient yoi" expansion and high rigidity, and a conducting shell fixed to said core and constrained thereby against expansion in the direction of the length of the core.

11. An inductor comprising a conductor disposed in a coil of at least one turn, said conductor having a core of nonconducting material having a low coeiiicient of thermal expansion ilxed to a shell of conducting material having a high electrical conductivity and a relatively high coefilcient of thermal expansion.

12. An inductance coil characterized by having a substantially constant inductance under varying temperatures, comprising at least one turn of a quartz rod plated with metal of high conductivity and having a high coeicient 'of thermal expansion.

13. The method'of maintaining the inductance of a coiled conductor having a shell of material of a high coeiicient of thermal expansion constant under varying temperatures, which comprises restricting the longitudinal expansion of said shell without interfering with the diametrical expansion of said shell.

HERBERT MUTH.