US2130432A - Air-cored high-frequency transformer - Google Patents
Air-cored high-frequency transformer Download PDFInfo
- Publication number
- US2130432A US2130432A US738198A US73819834A US2130432A US 2130432 A US2130432 A US 2130432A US 738198 A US738198 A US 738198A US 73819834 A US73819834 A US 73819834A US 2130432 A US2130432 A US 2130432A
- Authority
- US
- United States
- Prior art keywords
- air
- coils
- frequency transformer
- spool
- casing
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
- 230000004907 flux Effects 0.000 description 9
- 230000008878 coupling Effects 0.000 description 7
- 238000010168 coupling process Methods 0.000 description 7
- 238000005859 coupling reaction Methods 0.000 description 7
- 239000000463 material Substances 0.000 description 4
- 230000000694 effects Effects 0.000 description 2
- 238000004804 winding Methods 0.000 description 2
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- 239000000470 constituent Substances 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 239000010949 copper Substances 0.000 description 1
- 239000000428 dust Substances 0.000 description 1
- 239000012774 insulation material Substances 0.000 description 1
- 238000011835 investigation Methods 0.000 description 1
- 238000003475 lamination Methods 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 230000001681 protective effect Effects 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
Images
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F17/00—Fixed inductances of the signal type
- H01F17/02—Fixed inductances of the signal type without magnetic core
Definitions
- the present invention relates generally to coupling systems and more particularly to air-core transformers.
- the object of the present invention is to devise an air-cored high-frequency transformer which distinguishes itself from the forms of constructions customary in the earlier art in that it operrates with an extremely low leakage flux so that it insures a very high degree of coupling.
- the said outstanding advantages are obtained by shielding the spaces through which the magnetic fluxlines are to pass by means of a casing of high electric conductivity from the emergence of alter- 'l5 nating current stray fluxes, said casing being electrically subdivided so that it will not constitute a short-circuiting ring for the main flux.
- the shielding effect as here secured may be explained in such a way that such stray flux lines 20 as may escape, occasion in the conducting casing eddy-currents which, in turn, set up counteractive magnetic fields which will act in opposition to the leakage fields.
- FIG. 1 illus trates the invention applied to a transformer wherein the primary and secondary windings are fixed as regards their space relationship
- Figure 2 illustrates the application of the invention to an arrangement wherein at least one of the transformer windings may be varied spacially.
- Figure 1 shows an R. F. transformer in which the two coils I and 2 are positioned at a fixed 35 space relation to each other. These coils are supported by a bush 3 which possesses high electrical conductivity, and which is designed so that it will act upon such stray lines as may escape in the desired manner.
- coil 4 one of the two coils, i. e., coil 4 is fixed in space.
- the coil 5 is supported by a spindle 6, and by the aid of the latter, say, by revolving a small wheel or knob I, it is capable of being operated to different positions with reference to the coil 4.
- Both coils are outwardly shielded by the aid of a cylindrical casing 8 which serves to preclude stray lines.
- the shape of the casing may be adapted to the conditions prevailing in a given case; indeed, -it need not necessarily be cylindrical. It is also possible to use prismatic shields of other cross-section, say, four-sided elements.
- the arrangement described with reference to Fig. 2 could be used also as a regulable inductance, and not only as a transformer or as a coupling system.
- the wall thickness may be very small to make conditions adequate.
- the shield of solid or compact material, but to subdivide or stratify it into constituent layers, or even to use a compressed dust which may be molded with insulation material.
- An air core radio frequency transformer including a hollow spool of material having high electrical conductivity shaped to provide a central hub portion with a radially outwardly extending flange at each end, and primary and secondary coils wound alongside each other and in close proximity to each other and to the hub and flanges of the spool, the coils and spool flanges being radially co-extensive.
- An air core high frequency transformer including a hollow spool composed of compressed finely divided material having a high electrical conductivity, said spool being shaped to provide a central hub portion with a radially outwardly extending flange at each end, and primary and secondary coils wound alongside each other and in close proximity to each other and to the hub and flanges of the spool, the coils and spool flanges being radially co-extensive.
- An air core high frequency transformer including a hollow spool made up of laminations of a material having high electrical conductivity, said spool being shaped so as to provide a central hub portion with a radially outwardly extending flange at each end, and primary and secondary coils wound alongside each other and in close proximity to each other and to the hub and flanges of the spool, the coil and spool flanges being radially co-extensive.
Description
Sept. 20, 1938. R. SCHMOOK 2,130,432
AIR-CORED HIGH FREQUENCY TRANSFORMER Filed Aug. 3, 1934 INVENTOR PUDOLF SCHMOO/f ATTORNEY Patented Sept. 20, 1938 UNITED STATES PATENT OFFICE AIR-CORED HIGH-FREQUENCY TRANS- FORMER Application August 3, 1934, Serial No. 738,198 In Germany August 3, 1933 3 Claims.
The present invention relates generally to coupling systems and more particularly to air-core transformers.
The object of the present invention is to devise an air-cored high-frequency transformer which distinguishes itself from the forms of constructions customary in the earlier art in that it operrates with an extremely low leakage flux so that it insures a very high degree of coupling.
In accordance with this invention the said outstanding advantages are obtained by shielding the spaces through which the magnetic fluxlines are to pass by means of a casing of high electric conductivity from the emergence of alter- 'l5 nating current stray fluxes, said casing being electrically subdivided so that it will not constitute a short-circuiting ring for the main flux.
The shielding effect as here secured may be explained in such a way that such stray flux lines 20 as may escape, occasion in the conducting casing eddy-currents which, in turn, set up counteractive magnetic fields which will act in opposition to the leakage fields.
T wo exemplified embodiments are shown in the drawing to better explain the idea underlying the invention. In the drawing, Figure 1 illus trates the invention applied to a transformer wherein the primary and secondary windings are fixed as regards their space relationship, and, 30 Figure 2 illustrates the application of the invention to an arrangement wherein at least one of the transformer windings may be varied spacially. Figure 1 shows an R. F. transformer in which the two coils I and 2 are positioned at a fixed 35 space relation to each other. These coils are supported by a bush 3 which possesses high electrical conductivity, and which is designed so that it will act upon such stray lines as may escape in the desired manner. Inasmuch as by the aid of 40 the said coil body or coil-former '3 having the action of a shield or screen, conditions are made so that the same flux will traverse both coils, the shape of the flux-lines outside the arrangement is quite immaterial. Still, it would be possible to 45 mount a protective shell which will surround the coils also from the outside so that the coils I and 2 in this instance are perfectly embedded,
as it were, within a conducting case.
In the embodiment shown in Figure 2 only 50 one of the two coils, i. e., coil 4 is fixed in space. The coil 5 is supported by a spindle 6, and by the aid of the latter, say, by revolving a small wheel or knob I, it is capable of being operated to different positions with reference to the coil 4. 55 Both coils are outwardly shielded by the aid of a cylindrical casing 8 which serves to preclude stray lines. It has been found that by the aid of such a cylinder, which, of course, should surround the coils as snugly as feasible on the outside in order to exercise an appreciable influence 5 upon the stray lines, the flux can be held or crowded together, as it were, to a great extent so that the maximum coupling that is attainable will have a high value. The coupling factor, of course, is considerably higher than when two coils 10 of the same sort are used in exactly the same position but without the outside shield. What is essential in this connection is that the shielding shell should be open at its ends to permit emergence of the flux lines. In this way the flux lines have an opportunity to form a closed loop in the outside space. If the casing were completely closed the flux lines would be compelled to form closed loops inside the shielded space, V and this would tend to defeat the very purpose that is aimed at here. The shape of the casing may be adapted to the conditions prevailing in a given case; indeed, -it need not necessarily be cylindrical. It is also possible to use prismatic shields of other cross-section, say, four-sided elements. The arrangement described with reference to Fig. 2 could be used also as a regulable inductance, and not only as a transformer or as a coupling system.
So far as the leakage between the coils and thus also the attainable coupling and the inductance are concerned, the relationship between coil diameter and coil length is .of importance. In the light of investigations it, has been shown that it is a suitable plan to choose the said relationship in such a way that the diameter will be about from two to four times the length.
Inasmuch as for the production of the desired effect high electric conductivity of the casing is a prerequisite, it is primarily copper that would 40 come into consideration for making the casing, and it is also a good plan to make the casing walls of adequate thickness seeing that, if the thickness of the walls were smaller, eddy-currents would not get a chance to develop in the desired manner in order to displace the stray lines.
Where the frequencies are extremely high, the wall thickness may be very small to make conditions adequate.
It is preferable not to make the shield of solid or compact material, but to subdivide or stratify it into constituent layers, or even to use a compressed dust which may be molded with insulation material.
It is known that not only the coupling, but
also other properties of the high-frequency transformer are governed to a great extent by the leakage. However, inasmuch as the leakage varies with the frequency, it may be said that said properties are a function of the frequency.
However, in the case of any set of prevailing conditions it will be feasible to find a solution which will satisfy to a large degree the requirement of frequency dependence. The subdivision of the shielding means as described constitutes a way particularly suited in the said respect.
I claim:
1. An air core radio frequency transformer including a hollow spool of material having high electrical conductivity shaped to provide a central hub portion with a radially outwardly extending flange at each end, and primary and secondary coils wound alongside each other and in close proximity to each other and to the hub and flanges of the spool, the coils and spool flanges being radially co-extensive.
2. An air core high frequency transformer including a hollow spool composed of compressed finely divided material having a high electrical conductivity, said spool being shaped to provide a central hub portion with a radially outwardly extending flange at each end, and primary and secondary coils wound alongside each other and in close proximity to each other and to the hub and flanges of the spool, the coils and spool flanges being radially co-extensive.
3. An air core high frequency transformer including a hollow spool made up of laminations of a material having high electrical conductivity, said spool being shaped so as to provide a central hub portion with a radially outwardly extending flange at each end, and primary and secondary coils wound alongside each other and in close proximity to each other and to the hub and flanges of the spool, the coil and spool flanges being radially co-extensive.
RUDOLF SCHMOOK.
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE2130432X | 1933-08-03 |
Publications (1)
Publication Number | Publication Date |
---|---|
US2130432A true US2130432A (en) | 1938-09-20 |
Family
ID=7986400
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US738198A Expired - Lifetime US2130432A (en) | 1933-08-03 | 1934-08-03 | Air-cored high-frequency transformer |
Country Status (1)
Country | Link |
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US (1) | US2130432A (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2623932A (en) * | 1948-03-05 | 1952-12-30 | Raytheon Mfg Co | Magnetic coupler |
US5538205A (en) * | 1980-02-11 | 1996-07-23 | Hughes Missile Systems Company | Inductive look angle sensor for a radiation seeker |
-
1934
- 1934-08-03 US US738198A patent/US2130432A/en not_active Expired - Lifetime
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2623932A (en) * | 1948-03-05 | 1952-12-30 | Raytheon Mfg Co | Magnetic coupler |
US5538205A (en) * | 1980-02-11 | 1996-07-23 | Hughes Missile Systems Company | Inductive look angle sensor for a radiation seeker |
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