Deflection coil inside TV, deflects the electron-beam, using magnetic field. However this-deflection is not as simple as electrostatic deflection.

What is the actual mechanism behind working of deflection-yoke coil? I mean in which direction or spatial-arrangement it produce the magnetic fields?

(I searched web for several days, but I could not find anything helpful or clear.)

In web, I found 2 basic mechanisms.


Yoke-coil diagram 1 type 1

This- image is obtained from http://www.gradllc.com/images/Def.pdf .


Image -2 type 2 and Image 3 type 2

(Left one from http://obsoletetellyemuseum.blogspot.in/2010/03/deflection-coil-and-yoke-in-crt-picture.html , Image URL http://4.bp.blogspot.com/-1I5viFFbMWI/TXpTYhh9xjI/AAAAAAAAGzc/0R4qpHjBWlk/s320/DEFLECTION-9.jpg); and righ-one is from https://www.google.com/patents/US3192432 ; with URL https://patentimages.storage.googleapis.com/pages/US3192432-1.png .

Are they different thing? also,

the arrow-marked coil pair


What are the work of pair of coils marked with arrow? Is it an example of the 1st type ? (appears so from winding direction)

  • \$\begingroup\$ edited question and removed that misinformation on deflection direction. It was a silly-mistake. \$\endgroup\$ – Always Confused Jul 20 '16 at 8:29

The electron beam is always deflected at right angles to the magnetic field lines.

In your first image, horizontal deflection is created by vertical field lines, which are generated by the coils above and below the beam.

In your second image, the vertical field lines are generated by the coils to the left and right of the beam.

Note the difference in the orientation of the windings in the two images.

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  • \$\begingroup\$ That means 2 method exist? \$\endgroup\$ – Always Confused Jul 19 '16 at 15:45
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    \$\begingroup\$ Not in practice. I have never seen a commercial deflection yoke wound in the manner suggested in your top diagram. I think it's more of a conceptual drawing. All yokes used in practice are wound as shown in your lower diagram. \$\endgroup\$ – Dave Tweed Jul 19 '16 at 15:50
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    \$\begingroup\$ There is only ONE METHOD. Those are simply two different ways of documenting it on paper. A vertical magnetic field will deflect the electron beam horizontally, and conversely a horizontal magnetic field will deflect the electron beam vertically. That is a fundamental law of physics and all deflection yokes work that way regardless of the minute details of their construction. \$\endgroup\$ – Richard Crowley Jul 19 '16 at 16:33

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