Em 10/12/2017 08:22, phil escreveu:
All,I'm currently assisting in the construction of a ring type toroid (60" x 12") consisting of six tubes ( https://www.flickr.com/photos/33962508@N03/ ). Using Dr. Antônio Carlos M. de Queiroz's 'Inca' program ( http://www.coe.ufrj.br/~acmq/programs/ ) and, along with some help in its actual use from Bert Hickman, I now have a good idea of the expected toroid's capacitance. Now the six rings or hoops obviously need supporting in free space, and the conventional toroid method is a solid central disc in the horizontal plane supporting the outside minor diameter tube. I wondered just how much this solid central disc contributes to the shielding of the secondary, and if its replacement with support arms (like wheel spokes - but only four of them at 12, 3, 6, 9 o'clock) would leave the secondary more exposed to strikes, than if a solid disc had been used? (The effect on the capacitance value is believed to be small, so left out of the decision.)
You can use the Inca program to compare the electric field at the top of the secondary with a solid disk closing the toroid hole and without it. The difference is very small, unless the hole is very large. You can add one or two rings (that the program can simulate) along with the radial arms (that it can´t simulate) to improve the shielding, but the effect would be mostly mechanical.
Antonio Carlos M. de Queiroz _______________________________________________ Tesla mailing list Tesla@xxxxxxxxxxxxxxxxxx https://www.pupman.com/mailman/listinfo/tesla