Re: New System, was "Real Data--

To: tesla-at-pupman-dot-com
Subject: Re: New System, was "Real Data--
From: huffman <huffman-at-fnal.gov>
Date: Mon, 18 Nov 1996 08:49:21 -0600
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Hi Chuck,
I would like an invitation to see your coil when it's completed. I could
borrow a pair of binoculars to view it from a safe distance. ;) Bert, how
about a road trip.
Dave Huffman
> > 
> > Chuck Curran
> > Cedarburg, WI
> 
> Chuck,
> 
> I'm definately going to have to see this coil when you're done!! 
> 
> Your coil parameters look to be in the ballpark! By using a 0.1uF 20 KV
> cap, you'll have twice the energy/bang than if you used CP's next
> smaller size cap. Since CP charges $325 for their 0.05 uF and $450 for
> their 0.1 uF, the latter will double your "energy per bang" for only
> $125 more. As long as you can deliver enough input current to your pig
> to rapidly recharge the cap, you should get spectacular performance. 
> 
> Some other considerations: 
> 
> 1. With a 60" x 12" toroid, you'll probably see around 50 pF of
> effective capacitance after taking into account the "shading" from the
> top of the secondary coil. Also, the actual number of secondary turns
> will probably be somewhat less, since its very hard to maintain 100%
> perfectly close winding. I'd multiply the predicted number of turns by
> about 97% or so to compensate for this effect. The combined impact of
> these two factors increases the loaded resonant frequency of your
> secondary - my estimate is about 60-66 kHz. However, once you really
> start cooking, the ion cloud around the toroid should drop it down
> somewhat. I'd size the primary for 60 kHz nominal so that you get about
> 70 uH at a point about 2-3 turns in from the maximum number of turns. 
> 
> 2. Your primary current will be much larger. Assume you've set your
> system's gaps to fire in the range of 15 KV to 19 KV. Your primary
> energy/bang will be 11 - 18 Joules, and your peak primary current will
> be in the 575 - 725 Amp range. This may require you to beef up the
> design of your rotary (i.e., larger electrodes and forced-air cooling to
> remove the additional heat). 
> 
> 3. You won't need 15 turns on your primary. If you start the inner turn
> at a diameter 4" larger than your secondary, and use 5/8" or 3/4" copper
> tubing, a 11-turn coil should take you down to about 47 kHz, and would
> let you run at 60 kHz at about turn 8.5. A 15-turn coil would permit you
> to run with a 0.05uF cap, but would offer _no_ other benefit. Unused
> outside turns create unnecessarily high/hazardous voltages at the
> outermost primary turns from autotransformer action. Use only half the
> coil and you'll get 2X voltage multiplication at the outer turn.
> 
> Also, if you mount the primary coil assembly on a separate piece of
> plywood with a cutout in the center, you can adjust the coupling fairly
> easily (certainly easier than trying to raise/lower the secondary -
> you'll have almost 36 pounds of copper alone on the secondary).  
> 
> 4. You probably have to beef up your RF grounding system. The current
> peaks coming out of the secondary's base will be significantly higher
> than before - over 20 Amps. This is probably at least twice what you
> were running before... 
> 
> 5. The 12" aluminum ducting should work like gangbusters! You can always
> make your system break out wherever you want it too. Its MUCH harder to
> prevent it from breaking out too early - larger ROC is the easiest way.
> Where'd you get yours from?
> 
> Hope the above helps! 
> 
> Safe coilin' to ya, Chuck!
> 
> -- Bert --
>