US2882446A - Electromagnetic deflection system - Google Patents

Description

April 14, 1959 P. J. H. JANSSEN ETAI.

EI.ECTROIIAGNETIC DEFLEC'I'ION SYSTEM INVENTORS FETE JOHANNES H\IERTUS.MNSSE JGMN ANTON VERHOEF 4 AGENT llnited S;Atates Patent Peter Johannes Hubertus hassen and Jol1an Anton Verhoef, Elndhoven, Netherlands, assrlgnors, by mesne asslgnments, to North Amerlcan Philips Company, Inc. New York, N.Y. a corporatlon of Delaware --'Ihia inventioix relates to defiection coil systems for electrical apparati 1s.

ic e flection 'systemlfor the"hofilzntal deflection consists of two' saddlesh'aped coil halves 7 and 8, the operative partS of which"extend at rightn'gles fo the plane of the draw ing at 9, 10, 11 and 12 and are arranged within the nnular core 5. The ends of seid operative parts of each coil-half are intereolanectegl'by parts 13 and 14. The latter paits usually closelysurround the cireunxferencqof the tube-neck 6; here, ht yvever fdr"oonfiieniehjtliey are shown bent' outwarclso tha t the coil's'l, 2, 3 'arid4 may bc.seen. 7

In Eig, 2, in'lvvhigihcrrespoljcling t'l?ig. 1'a1e designzit'e'd by likere'afrehe'huirierzils, tl1e Pakt 'f theSys- A 'known* electromagnetic deflection system for'"tleflecting an electron beam in two directidns at right angles 'to each-oth'er-comprisas four coils wound -toroidally on a cYlindficab'core of fenomagnetic material for deflection in oneof the directions. The first and the third coils are diametrically opposed and co'nnected in parallel with one 'another, and the second and fourth coils are also diametrically' opposed and connected in parallel with one another, while the two parallel combinations are connected in series' with one another. are employed in television systems, in which use is made of coils wound in difierent senses, which entails additional expense during the manufacture.

lt is an objectof the invention to provide an electromagnetic deflection system in which this disadvantage is obviated.

lt is a further object of the invention to provide-a deflection system wherein the polarity of the stray voltages which are induced in each coil by the coils producing: deflection in the perpendicular direction is auch as to prevent difficulties with respect to insulation of the coils from the core of the system.

The system in accordance with the invention is char- Deflection systems of this kind the same manner, whereas the second and the third coils being provilded on the core in the opposite manner to the first and fourth coils.

An embodiment of the deflection system in aceordance with the invention and its further advantages will now be described with reference to the aecompanying drawing, in which:

Fig. 1 shows an embodiment of a system according 10 the invention for deflection in two directions;

:' nectcd to one another and to the supply-souree;

Fig. 5 shows an electrie clrcuit ararngement lncluding the system 01 the invention and the lnterconnectionr between the different parts of the deflection system.

In Fig. l, there ls provlded a cyllndrical annular core 5 made of ferromagnetlc material, for example, the terromagnetic ferrltes, which core usually conslsts of two Parts in order to enable coils to be mounted tbereon. Four toroidal coils 1 2, 3 and 4 mrround the core 5. which eoils in comblnation furnlsh the deflection in the verllcal direction for, for exarnple, an electron-beam in a cathoderay tobe. In Fig. l. only the glass wall 6 o! the tube neck is shown. The coil: l. and 3 are mounted diametrically oppodite one another. as are the coils 2 and 4. In the embodiment shown, the part of the de I f, now, the C'oils 1'and 3 are eonnected in parallel with one anothei, the electromotive' force which .isfinduced in the.thus produced closed circuit by the/horizontal flux is zero, since the fluxes are in oppoiste directions in thest coils, so that i n this circuit no troublesome circulating currents will fl0w. The sarne applies to the parallelcornbination' of the coils 2 and 4 with respe'ct to the horizontal flux. If, now, the two parallel combinations are' connecte'd in se'r"ies; with one an0ther, in this series'cirflitan leetrornotive force is also rl'ot'induce d by the horizontal flux. This will be seen from referen'ce to Fig 5, in which the"circuit arrangement of the coils 1, 2; 3 and 4, which areshown as lnductance coils, is shown and in which the polarity of the'electromotive force induced in eacl rc'oil by 'tlte horizontal 'flux isindicatbd by plus and rrl1i i1tlsi signs'.' Thus, in the closed circuits 1, 3 and '2, '4'no electrolnotive force is induced at all, and in the series connection of the circuits 1, 3

and 2, 4 the indueed eleletromotiireilfrces will also cande'l each other.

Fjg. 3a i; an elevation of a coil such as those illustfatbd in'Fig; 2 and designted 1,2, 3 er 4. The core 5, not shown, pas ses thro ugh the apcrture 19. The turns cf the coil are wound in several layers and, for the sake of clearness, the and or startihg turn 20 situated in the bottoxn or inner layer iS shown by a broken line, while the other end or terminal"turn 2 l situated in the outer or toplayer is shown'by a full linep The same applies to Fig. 3b, which shows a side elevatldn of the coil. In

' the latter figure, the end 20 shown by the broken line is arranged on one side and the end 21 shown by the full line is nrranged on the 'Other side of the core, with a view to a better understanding of Fig. 4 in which these ende are shownlln the same manner.

Flg. 4 sl 1ow s the mnnner, in the System in accordance witl; thelnventlon' in 'which the ebila are supported from tl'16corej5fivhlehls ahown in developed form. The coils 12 3 and 4 ar'e ldentlcal and consiequ ently wound identieally The eolls 1 t\nd'4 are"mounte'd on' 'de core in the Sam'e1rnanner, both 'having the (und er uarting turn sltuat'ed in the bdttom layero'fthe coil at the left band sldeln the drawing.

The orlenttion of the colls 2 and 3 is also the same butthey'are rptatedthrotxgh relative to the di ls 1 and 4, so tha t the ends 9x atartlng' turns of the coils 2 and 3altuated in the bottom la'yer a re'at the rightband xldelnFl'g. 4. In addltion', the colls 1 and 3 are oonnected in parallel with one another, as hasbeen nrexitloit'ed abave, in thatthe ends thereof situated in the bottom layen on the one hand amlthd ende sltuated in latented Apr. 14, 1959 A

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