CRT Deflection Yoke

This example highlights the advanced coil modeling capabilities of the MagNet analysis package. The winding of a deflection yoke is quite complex, and modeling the individual turns is not realistic with the current generation of geometric modelers. Instead, MagNet offers a powerful stranded coil modeling scheme which allows the user to specify the form of the coil, and then automatically calculates the current distribution that would be obtained if the coil was composed of many strands of wire. A recent publication of this technique (in IEEE Transactions on Magnetics, Vol. 40 , No. 2, pp. 810-813, March 2004) shows that, as always, Infolytica is working on the forefront of computational electromagnetics to make possible the simulation of ever more complex models.

Results

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The image at right shows the stranded current distribution found by the automatic stranded coil detection scheme. The coil is defined by simply specifying the input and output terminal faces of the geometry. MagNet automatically determines the current density vector field which would result from the uniform winding turns density of a stranded coil.

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This image shows the resulting magnetic field along a slice containing the axis of the yoke. Note that both this image and the one above it were obtained from a solution to the quarter model. Generating the views of the full fields from a solution for the quarter model is easy using the FullFieldView script.

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This is a photo of the original deflection yoke.

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The "Trajectory Assistant" post-processing tool allows the trajectory of charged particles to be plotted in three dimensions. The graph at right shows the path of a 20 keV electron through the yoke.