A LUA file for BELA (a help to build electrostatic model of TC)

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: Finn Hammer <f-h@xxxx>

All,

Dmitry showed an electrostatic analysis of his TC, made by a program 
called FEMM4

I thought it would be cool to be able to automate the construction of 
the model, because FEMM is not a fast application to work with.

The fun part is designing the grounded shield and the dielectric stuff.

FEMM4 is a combination of a magnetic and an electrostatic calculator. 
The electrostatic module was formerly called BELA, but is now a part of FEMM4.

Over on Yahoo groups, I met a guy, Senthil Ram, who not only offered 
to- but actually _did_ write a script to build the model of the secondary coil.
With that script as a model, I was able to add the code for the 
remainder of the coil, as well as position the coils relative to Y=0.

It only does cylindrical coils, not pancake and not conical, but that 
is because I`m too lazy to do the code. Perhaps a job for you?

If you would like to model a coil of yours, download the file from here:

http://home5.inet.tele.dk/f-hammer/DRSSTC.lua

Then get FEMM 4.01 from here:

http://femm.foster-miller.net/Archives/bin/

At the bottom of the files menu: "load LUA script" load DRSSTC.lua 
and follow the prompts, to describe your coil and work out the 
electrostatic stress imposed on the primary by the secondary.

Imput is mm, and the inputs are meant to be self explanatory, perhaps except
no. 5  "Maximum Segment Degree"

This determines how many segments a circle is divided into.
If you make the input =1 then each circle will consist og 360 
segments, and it also means that the sourrounding mesh that will be 
generated to define the matrix that calculations are carried out on, 
will become very fine meshed.

And that calculation time will increase, as well as memory use will increase.
I think that a value around 20 is a good value to use but YMMV here.
input no.13, "triangle size (o.25-3)"
Has a similar aim, namely to controll the size of the grid. Try with 
3 to start with, go lower if you feel better resolution is in order.
I went out and got a 1meg memory module for my TravelMate 240 laptop, 
and as long as I don"t try to model all 3000 secondary turns, I`m 
alright. Try a couple houndred turns to start with.

I hope it may be of some help to someone apart from me.

Cheers, Finn Hammer