RE: Bundt Pans and Toroid Construction

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Stephen Conner by way of Terry Fritz <teslalist-at-qwest-dot-net>" <steve-at-scopeboy-dot-com>

At 18:35 19/06/03 -0600, you wrote:
>Original poster: "Christopher \"CajunCoiler\" Mayeux by way of Terry Fritz 
><teslalist-at-qwest-dot-net>" <cajuncoiler-at-cox-dot-net>
>
>
>I like this idea you're going with, as it may better
>work within my budget.  Any particular brand and size
>of cookware that you prefer?  Will the current formulas
>for calculating it's capacitance work without mods?

I just kept an eye out at second-hand shops and the supermarket. I looked 
for things that would assemble into the right sort of shape without 
cutting, because stainless steel is really difficult to cut and drill. 
Handles that are spot-welded on are a pain because the heat hardens the 
welds and makes them impossible to drill out. I ended up just clamping the 
handles in a bench vice and ripping them off with brute force :)

As for the capacitance, I've applied the toroid formula to a topload made 
from serving dishes with reasonable accuracy. Two dishes screwed together 
is almost the same shape as a toroid, minus the hole in the middle, which 
(IMO) doesn't really make much difference to the capacitance anyway.

I suppose you just need to use a bit of imagination to figure out the 
dimensions of the equivalent 'toroid' or 'sphere' and leave a bit of room 
for adjustment if it doesn't work out (always a good idea anyway) Or use an 
RF generator and counter to measure the resonant frequency of your 
secondary/topload once you've completed it, and then design the primary 
circuit around that.

My most successful topload was just made from a salad bowl. I used the bowl 
on its own but it developed a lot of corona from the edge, so I added a 
shield that I cut out of an aluminium lampshade and beat into shape with a 
mallet. It looks a bit rough (cooking grade :D ) but the streamers glide 
all over it with no apparent hot spots, so it's apparently good enough.

There are pictures of all this stuff on my website.

Steve C.
http://www.scopeboy-dot-com/