US2925571A - Interceptor choke - Google Patents

Description

Feb. 16, 1960 J. R. WIEGAND INTERCEPTOR CHOKE 2 Sheets-Sheet 1 Filed March 18, 1955 INVENTOR. Joan R. WIEGAND BY W AI'YJH VF) United States Patent INTERCEPTOR cnoxn John R. Wiegand, North Valley Stream, N.Y.

Application March 18, 1955, Serial No. 495,135 4 Claims. (Cl. ass- 155 This invention relates to new and useful improvements in electrical chokes.

This application is a continuation-in-part of my copending application 449,838, filed August 16, 1954, now Patent 2,798,987.

Electrical chokes find numerous applications in electrical and electronic equipment wherein they function as frequency discriminative attenuators and the like. Usually a choke comprises a laminated magnetic core having a coil of conductive wire wound thereon. Electrical impulses to be afiected by the choke are transmitted through the coil. If the impulses are of the appropriate frequency relatively little attenuation is encountered. However, impulses of other frequencies are attenuated to a greater degree. l

The principal object of the invention is to provide, an interceptor choke which is more frequency discriminative than existing chokes, but which may be constructed of the same materials as the latter.

Another object of the invention is to construct the choke in such manner that the same eifects a damping action on noise superimposed on the impulses transmitted through the coil.

A further object of the invention is to construct the choke in such manner that a flatter frequency response is exhibited and a greater frequency range provided than is possible with prior art chokes utilizing the same materials.

Still another object of the invention is to provide an interceptor choke which provides for a large increase in the storage factor of the coil with a noticeable decrease in charge and discharge time.

For further comprehension of the invention, and of the objects and advantages thereof, reference will be had to the following description and accompanying drawings, and to the appended claims in which the various novel features of the invention are more particularly set forth.

In the accompanying drawings forming a material part of this disclosure:

Fig. 1 is an isometric view of the choke of the invention encased in a plastic housing.

Fig. 2 is a side elevational view of the choke with the housing removed.

Fig. 3 is an enlarged isometric view of the choke with the housing removed and with only the first few windings of the core in place.

Fig. 4 is a perspective elevational view of a form on which the coil and the core are wound.

Fig. 5 is a diagrammatic illustration of the coil with a single core section wound thereon.

Fig. 6 is a diagrammatic illustration of a same system utilizing the choke.

Fig. 7 is a graph illustrating the characteristics of a 10,000 cycle interceptor choke.

Fig. 8 is a graph illustrating the relative response characteristics of a choke according to the invention and another choke.

2,925,571 Patented Feb. 16, 1960 "ice Referring to Fig. 1 the choke of the invention is encased in a plastic housing 10 from which a pair of conductive leads 11 project. Interiorly of housing 10 the choke includes a form 12, an annular coil 13 and a wire core 14 wound on the form (see Figs. 2-5). Form 12 includes a pair of substantially square side plates 15 separated by a centrally located, square tube 16. Form 12 is constructed of any suitable insulating material. Each of side plates 15 is provided with corner extensions 17 which extend diagonally outward from the four corners and are wider at their outer than at their inner endsJ As best shown in Fig. 3 the leads 11 which project from the housing 10 in Fig. 1 comprise a pair of conductive rods each having a widened'inner end folded about one of the extensions 17 as at 18. Coil 13 is wound on the tube 16 between the side plates 15 and its ends are soldered or' otherwise secured to the folded portions 18 of the leads as at 2.0.

The core 14 comprises magnetic wire wound on the form 12 as best shown in Figs. 2, 3 and 5. The wire may be .003 in. diameter 50% nickel-iron alloy wire. Refcrring to Fig. 2 the core 14 is wound in four sections 14', each encompassing adjacent corner-extensions 17 of the side plates 15. Each of the four sections 14' is wound as shown in Fig. 3. The winding is begun within the tube 16, extends out of the tube as at A, passes adjacent one side edge of a corner extension 17 of the near side plate 15, crosses the coil 13 to the far side plate where it passes adjacent the opposite side edge of aligned corner extension 17. Thence the winding extends through the tube 16 and out as at B. Loop B passes adjacent the opposite edge of the corner extension 17 of the near side plate to that engaged by loop A, and traverses diagonally across the latter loop at 30 in crossing the coil 13 to the far side plate. Loop B then extends through tube 16 and emerges as loop C identical with loop A, etc.

It will be seen, therefore, that as shown diagrammatically in Fig. 5 the several loops of each core section 14' traverse the central opening in the coil in parallelism interiorly of the latter at 31, but traverse the coil at substantially right angles to one another exteriorly of the coil at 30. When each section of the core has been provided with the requisite number of loops, the next section is begun until all four sections 14' are wound to make up the complete core 14.

When the core is completely wound as shown in Figs. 2 and 3, the several core sections are arranged in a balanced four-leaf clover pattern on each side of each of plates 15. Each pattern has four elongated lobes whose long axes lie along diagonals of the plates, with the long axis of each lobe disposed perpendicular to the long axes of the two lobes adjacent to it. The strands of the core are disposed in substantial parallelism with each other within the tube. The strands of each core section cross each other between opposed corner extensions 17 of the plates 15 on the outside of the coil 13.

A frequency response curve for a nominal 10,000 cycles per second interceptor choke is shown in Fig. 7. As illustrated, the response characteristic is such that the curve is extremely flat up to 4,000 cycles per second, rises, relatively gradually up to about 8,000 cycles per second and then very sharply to 10,000 cycles.

Referring to Fig. 8, frequency response curves are shown for two chokes. Curve I shows the response for a choke having a four section magnetic core 14 wound on a coil 13 as shown in Fig. 2. Curve II shows the response for a choke having a coil with exactly the same number of turns and shape as the other coil; but the core of the second choke is an ordinary flat laminated rectangular member on which the coil is wound. The inductance of both coils is four henries and the DC. resistance of both 3 a coils is 1400 ohms. Bothchokes have a 50-50 nickeliron content in the magnetic cores and have the same weight.

As hcw n 8, u ve l rr s s ra ua to a fi neeketQOQ cyc es a d to Qn pea t ablwtlZflQ 5 yc s Neith p ak is sh p o W fined e curve I for the choke of the present invention, however, does otfbegin to rise appreciably until about 9,000 cycles Pe econd a dma sharply at 1 0 clespe s ond- Qbviously the choke of the invention is much moreirequency discriminative and efficient and is ideally adapted for passing an extremely narrow band of frequencies.

A i pl examp th ma t e! in w c t e "choke. f' iive tiq i u ef is l u ra ed d a ammati a in 6. gA slshown, acl oke' llis connected in a. series o'ndenser. Afrnicrophone 25,

, li wi ali s ng: 2. c ager-1 rel 2 nd. a

d a battery -2;2"ar e a my ofia ara emflie ei reflect "enejfgization'of' e rel t e. au o bi sin th ara ide wi a whistle or the like which utilizfesthe' peaking frequency of the choke. Normally the relaysco'il would be held deenergized by the relatively high attenuation efiected in Qhoke '21. However, on sounding of the whistle of the appropriate frequency animpulse is generated by rnicro phonefj vwhichenergizes the relay coil causing contacts a 29 to close.

,.'Ihe choke of the invention, may be used in many other 30 environments, for example, hearing aids, computers, etc.

At this point it is deemed wiseto point out that the choke has been found to effect a damping action which severely'attenuates noise frequencies superimposed on the impulses applied to the choke when these frequencies diner from the optimum frequency response range of the choke. Thus, the choke of the invention improves the condition of the impulses applied to it.

It will also be, seen that the crossings of the core as shown providefor a large increase in the storage factor (Q) of the coil with, a very noticeable decrease in charge and discharge time, making it ideal for pulse work. Further, by changing the diameter of the core wire and the amount in relation to the copper coil, the maximum Q or storage factor can be adjusted to any esired frequency. $uch flexibility of changing or adjustment is *Q IY d fii ult h t e o d a laminated choke w ich. can never reach such a high storage. factor on a desired requ nc "Tenant- 5;

While I have illustrated and described the preferred embodiment of my invention, it is to'be understood that I do not limit myself to the*precise construction herein disclosed and that various changes and modifications may be made within the scope of the invention as defined in the appended claims. 7

Having thus described my invention, what I claim as new, and desire to secure by United States Letters Patent 1. An interceptor choke, comprising an insulation form having square side platesand a centrally disposed tube extending be ueenthe p ates a i le coi wound around said tubebetween said side platesfsaid coil having two terminals for connect-ionito an external circuit, and a core of magnetic wire having strands wound about the coil, 7 extending through the tube and over edges of the side plates, said core being wound in four similar looped sec- 2 An in e ep or oke accordin to @aia"1, .wte

ach. the wit n he tubej Anv iate c chok a qnlit e to claim? wherein vch c i Pro id th-a j? qn'a ly ext nd n c rner said strands are disposed in snbs tantial'parallelisn with i eli iqn, th 'lt ansl o sah sq a crossi cah the e uts de o t so s-I "A interwp 9 9 2 accordin to. cla m 3. fu ile: comprising a pair of conductive rods having ends respeci qlded a o nd, two ex ens on ctt t P tes t e wo endecf th 99 15 be ng leq c lyccnnecte. to the. respective ends of' the rods between opposed corner extension J 'ofjtheft o plat es on References Cited; inthe file of this patent U IIEDSTAIES tenants 1,667,705 Wysiecki Apr. 24, 1928 1,743,089 Bandur 'Ian. 14, 1930 2,314,912 Troy .Mar. 30, 1943 2,425,155 Jarvis Aug. 5, 1947 2,479,656 'Wiegand Aug. 23,1949 2,667,624 Bels'; Jan. 26, 1954 2,753,533 Houser July 3, 1956 2,798,987 Wiegand l July 9, 1 957

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