US1631599A - Variable condenser - Google Patents

Description

June 7, 1927. 1,631,599

A. LEIB VARIABLE GONDENSER Filed Sept. 14. 1923 awww/woz AU GU ST LEIB 3513 his @www2-@6kg Vl/W4 i Patented June 7*, 1927.

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AUGUST LEIB, or BERLIN, GERMANY, AssIGNoR To eEsELLscHAET EEDRAIITLOSE .TELEGEAPHIE m. B, n., or BEELIN GERMANY; A CORPORATION oE GERMANY.

VARIABILE ooNDENsER.

Application led September 14, 1923, Serial- No. 662,612, and in Germany August 17, 19,22.

' 15 dielectrics, suoli as small losses, continual variability bythe aid of as simple a mechanism as feasible, low weight Aand cheapness, have been taken into consideration toa large extent in the development of the condenser .of this invention, which also affords the prerequisites for cheap, large scale manufacture, since the'condenser does not require high-precision workmanhsip.

The demand that .the losses shall be -low and the complete fulfilment of the same makes the use of a high-grade dielectric of paramount importance. For this reason the material most suitable for the purpose isA mica, since, as is well known, this material involves only very small losses even when of extremely thin lamination., The economical use of this high-grade dielectricv of a thickness varying between 0.02 and 0.03 .mm., on the one hand, is made possibleV by perfect and homogeneous contact between the solid coats and the mica, so that inclusions of air spaces involving a lower dielectric constant are avoided, while, on the other separate sets of condenser plates.

` hand, by the constructional formation ofthe adjusting mechanism, the thin-walled dielectric is made entirely free from mechani- -cal stresses-in spite of the absolute contact. Fig. 1 shows a cross section of my condenser.

Figs. 2, 3. and 4 show one form of my condenser in diferent rotative positions.

Figs. 5, 6 and 7 show another form of my condenser in dierent rotative positions.

Fig. 8 is across section of my condenser mounted in a dial which is mounted in a support or panel. l

Fig. 9 is a front view of the arrangement shown in Fig. 8. Y

Referring to Figs. 1 to 4 inclusive, C de'- notes the extremely thin mica laminas, each having the thickness of 0.1 mm., which togethe1'.with annular ring D form a closed shell'orcasing. This-shell is half illed with the liquid condenser plate orcoat A which may be any liquid conductive substance `such as, for instance, mercury. To

eliminate sensitiveness to shocks and vibrations tlie other halt' of shellis filled with a paraiin oil F. B1 andB2 denote the solid condenser plates, each substantially semicircular in shape, which areV fastened to the exterior of the shell. They are connected 'together to.form in effect a single condenser .site condenser plates. When the-dielectric 'shell is rotated 90 to the position shown in Fig. 3, the capacitance between the liquid condenser llate A and solid. condenser plates B1, and B'2 1s substantially one-half the maximum capacitance of the condenser. When.

the dielectric shell isrotated a Jfurther 90,

as shown in Fig. 4, so that the'solid plates and the liquid plate are in register,the ca' Y pacitance of the condenser is maximum.

Referring now to- Figs. 5,Y 6 and Y'7 there is illustrated a condenser identical with the condenser shown in Figs. 1 to 4 inclusive with the exception that each set of solid plates B1 and B2 are divided in half to forni The plates B1 and B2 of each set .are connected' together to form, in 'eiect, a single plate.

This type of condenser may be called a double condenser since there are two separate capacita-nces, onebetween the liquid plate A and one set of solid plates and the other between liquid plate A and the other 'setof solid plates. Fig. 6 shows substantially no capacitance between either set of solid condenser plates and the liquid condenser plate.

Fig. 5 shows a condition of maximum ca` pacitance between the liquid plate and one set of solid condenser plates with substantially no capacitance between the liquid condenser platev and the other set of solid condenser plates, while Fig. 7 shows these conditions reversed by rotating the dielectric shell 180. A Referring to Figs. 8 and 9, the condenser is shown mounted in av pocket 3 in the rear face of the dial E which is made of insulating material. The dia-l E ispositioned in an opening in support or panel P and is rotatably held there by means of plates 1 and 2 appropriately fixed to the panel. The dial Ev is provided v'vith an annular groove 4 which provides a journal portion to cooperate with the plate 2 which operates as a bearing. `The plate 4 and the dial E adjacent plate 4 are provided with markings A to tell the operator the position of the condenser. I

The plate 1 is provided with an opening 5 thru which the Wires B and G leading to the solid and liquid plates respectively pass.

It should be noted that by appropriately shaping the solid plates or the chamber for holding the liquid plate, the effective areas of the plates, and hence the capacitance may be made to vary, according to any desired law when the dielectric is rotated by equal increments. 't

By the principle described itv is made feasible to build not only large but also very small continuously variable condensers With the use of extremely thin-walled mica laminae. No mechanical stressing of the mica laminations happens, While short-circuiting tirely precluded if the construction is chosen of an appropriate nature.

Having describedfmy invention, what I claim is:

1. A variable condenser comprising a rotatable dielectric,` a condenser plate fixed on one side of 'said dielectric, a stationary liquid condenser plate on the other side of said dielectric, and fluid means for preventing undesired motion of the liquid condenser plate, due to itsl sensitiveness to shoclnand vibration.

'2. A variable condenser comprising a rotatable shell of dielectric material, agcondenser plate fixed on the exterior of said shell, a stationary liquid condenser plate within said shell, and a bodyof insulating material whose specific gravity is less than that of said liquid condenser plate also within said shell for preventing undesired motion of the liquid condenser plate.

3. In combination, a panel having an opening therein and an annular bearing member ixed'to said panel, a rotatable dial within said opening having an annular journal portion cooperating with said bearing member' and also having a knobland an indicating portion extending from said knob to said journal portion, said dial containing means for varying a constant of an electric circuit.

AUGUST LEIB.

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