Re: transformers...

> All transformers are not created equal.  Neon Sign transfromers and 
> Oil Burner ignition transformers are designed for arc/spark duty 
> (quasi short circuit).
> Microwave oven transformers are not.

I know that neon sign xformers are buit with a magnetic shunt to limit 
the current during a short-circuit condition and that microwave oven 
xformers aren't, but what other differences are there and how would 
they affect their use in Tesla coil circuits?  

I wired two 4kV microwave oven xformers in series to give 8kV out, and 
(if my meter was correct) I was pulling over 60 A from the wall (on a 20 
A breaker!) when I was drawing an arc!  Obviously, to use a microwave 
oven xformer you need external current limiting (like the larger pole 
and potential xformers), and you can saturate the core and heat things 
up if you try to draw too much current, but I assumed they would work 
fine if you limit the current and don't drive them too hard?  A few issues 
ago, the TCBA newsletter featured a design where the builder rectified 
the output of a couple of microwave oven xformers for a DC powered 
Tesla coil and was getting great results judging from the pictures and 

Steven Roys (sroys-at-radiology.ab.umd.edu)