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Alex, I see very little difference between the two tertiary coils - select your preference. In my earlier response, I misunderstood the meaning of the 3 mm clearance. I interpreted it as the diffence in radius of the primary and secondary/driver coil. I now realize you were describing the air clearance between adjacent turns. The larger diameter of you secondary/driver should work very nicely and the 3 mm spacing should also be OK (assuming sufficient clearance between the secondary/driver and your primary). However, the 3" clearance between the primary and secondary/driver will not be sufficient unless you immerse both the primary and driver in oil. Just immersing the secondary/driver in oil will merely increase the stress in the air gap between the primary and the container holding the secondary/driver, leading to excessive corona and eventual puncture. The most difficult part of magnifier design is simultaneously obtaining a high coupling coefficient AND high voltage standoff capability between the primary and your secondary/driver. Tight E-field control and prevention of initial corona are essential. You may want to consider increasing the primary diameter as you go up in height - making it a conical shape to provide more clearance to the secondary/driver to withstand the greater voltage stress. You could also decrease the clearance at the base of the primary where the voltage stresses are lower. This should maintain tight "k" while increasing overall primary:secondary breakdown strength. Remember that the numbers of turns on various windings and turns ratios have little bearing in the theoretical analysis of magnifier designs since the theory deals with how energy can optimally transfer between the primary, though the various inductances and capacitances in the system, to the teriary coil. How one practially achieves the appropriate inductances, coupling coefficients, AND voltage stress capabilities are practical design and ngineering challenges that are beyond the capabilities of the current analysis that magnifier design tools provide. I'll review the design parameters above and get back with you as soon as I have a bit more time. You may also wish to review your proposed design with Antonio Carlos M. de Queiroz (acmq@coe.ufrj.br) since Antonio is currently the person who's most knowledgable about magnifier design theory. Best regards, -- Bert --
: Hi Bert,
: thank you for your answer.
: At this time my main problem is,
: I have to wind the extra coil(TC),because the weather is good.
: The extra coil should have dimensions: 12,44"diam.x
: 58.17"length 1025 turns closewound AWG16 ohms
: or can I also use: 12.44"diam.x61"length 1075 turns closewound
: AWG16 13.5ohms
: (I would prefer this)
: two stage toroid (one elevated) planed
: Could I use so many turns for an effective extra Coil !
: The other construction data´s are not calculated exactly.
: Second./driver: 53.1" diameter 3mm spacing 24.2"length AWG16
: 142turns ~30.5mH ~2000ft wire
: You wrote that 3mm will not be sufficent.
: But if I have a greater distance,say 5mm I need for same Inductance
: more wire and more turns.
: example: 53.1" diam. 5mm spacing 42"length 168 turns!! 30.5mH
: 2330ft wire.
: More turns in driver means more voltage stress.How could
: this stress minimized?
: Why caculate magsim L2=30.5mH and the design formular and don´t give
: turns-ratios?
: The sec./driver wire should be welded in Polyetylene and possibly filled
: with oil.On the top winding should be a Toroid.
: The primary: 59"diam 0.47"copper-tubing 1.06"spacing
: 10turns 15.7"high helical
: Above the top winding should be an isolated rim.
: The planed power is around 10KVA.
: The planed magnifier system could look like in the Tesla
: Patent:1,119,732 Dec1914
: best regards and thank´s for your short time.
: Alex
:
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