Re: microwave trans

        Re: microwave trans
        02 Apr 97 17:48:03 EST
        Alan Sharp <100624.504-at-compuserve-dot-com>
        "INTERNET:tesla-at-pupman-dot-com" <tesla-at-pupman-dot-com>

Greetings all,

Kenneth wrote:

>can you give me more info on teh inductive balast you built. this
>could be a solution to my problem. so far i have 2 transformers, one
>600w at
?2000v and the other 1200w at 2000v. if i put in two more (i don't 
>know the voltage because i havent got them yet) your
>coil might limit the current and give the 8000+ volts i need.
>how did you build it ? a large coil in series to the 220v ?<

I'm also trying out microwave transformers.
I've been using a 5500v 350mA dry transformer that I have,
one end to ground and then a 2000v 800W microwave transformer.
I'm using a 2kw convector heater in series with the mains
as current limiting. The microwaves transformer does
have a current shunt but I'm not going to rely on that on its
own. I would want to build some inductive ballast eventually.
Would this asymmetrical arrangement work in a tesla
coil? (I would not be grounding the coil primary and I
would have a safety gap from each side of the transformer
to ground). I had a book Babina Press on coils and transformers
which I'm sure had a chapter on winding your own chokes -
naturally now that I'm looking for the book it has disappeared
through a split in the space time continuum. If it appears in a parallel
universe near you could you send it back to me (by email of course)

I'm using then together to drive a Jacob's ladder I built
with a couple of pieces of 1/2" copper pipe. It arcs at 
1/4 inch gap but the arc sticks moving the pipe back slightly
sends it slowly upwards. Is the problem too low a voltage or
likely to be in the geometry?

I built the Jacobs ladder first to see the arc and its likely
problems. I now appreciate that an arc can carry a very
high current and that quenching is going to be a problem.
(I've got some 1.5" copper pipe and I plan on building a multiple
static gap - the microwaves also yielded fans).

I've also got two large (2.5" * 7" cylinders) 0.01uf caps 30kV DC
- with big screw terminals which I hope will stand up to 5.5 - 7.5kV AC.
 In theory I only need 400 watts with these - fine for starters but how
do I arrange things to avoid having 3KW flaring uselessly in the gaps?

have fun,

Alan Sharp (UK)

(relieved mosfets world are celebrating that I've moved over to gaps 
for a while - wonder how much copper pipe I can blow?)