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Magnifier/Teslacoil design
Posted by Alex on 8/27/2003, 11:23 am sec.coil: prim.coil: From this data I get: best reagards
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Re: Magnifier/Teslacoil design
Posted by Bert Hickman on 9/4/2003, 12:05 am, in reply to "Magnifier/Teslacoil design" Hi Alex, Sorry for the delay in responding. I have been out of town on business for a week and a half and have also doing some engineering consulting work. These activities have dramatically (and hopefully only temporarily) reduced the time I can devote to Tesla-related things. I did intend to answer your posting (and two others) on the board. In the meantime, can you provide me (via the message board) with the proposed dimensions and relative geometry of your driver primary and secondary coils? As you already have surmised, the main challenge with trying to obtain high coefficients of coupling between the driver primary and secondary will be in preventing secondary to primary flashovers. E-field control, and spacing will be most critical. 3 mm spacing will definitely NOT be sufficient. To maintain sufficient clearance AND high coupling, you'll need to use a helical primary with large diameter coilforms. The larger the primary and secondary diameters, the larger the spacing can be between coils for the same coupling coefficient... distance that you'll need to help prevent flashovers. The primary winding should use large diameter tubing to increase corona inception voltage. You may need to taper the primary winding outwards at the top to provide more clearance from the secondary. You may also need to supplement this with a larger diameter anti-corona ring at the top of the primary winding. The primary and secondary directions should be the same to help reduce voltage stress. You will most likely need to augment the insulation between the coils with rolled polyethylene sheeting. Best regards, -- Bert --
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Re: Magnifier/Teslacoil design
Posted by Alex on 9/4/2003, 1:01 pm, in reply to "Re: Magnifier/Teslacoil design" The planed magnifier system could look like in the Tesla Patent:1,119,732 Dec1914 best regards and thank´s for your short time.
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Re: Magnifier/Teslacoil design
Posted by Bert Hickman on 9/5/2003, 8:52 am, in reply to "Re: Magnifier/Teslacoil design" 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 --
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Re: Magnifier/Teslacoil design
Posted by Xtreme Technology on 12/1/2006, 7:32 am, in reply to "Re: Magnifier/Teslacoil design" --Previous Message--
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Re: Magnifier/Teslacoil design
Posted by alex on 9/30/2003, 5:18 pm, in reply to "Re: Magnifier/Teslacoil design" Thanks for your help.
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