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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?  
	That is what i waas discussing, the current limit effect in the
	sign/oil burner transformers.  Those two are designed ot handle an arc
	or spark load.  The Oven transformers are not.

>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!)
	Methinks something was not happening as expected.  60 (real) amps
	(or 60 out of phase amps) would trip the breaker REAL QUICK.

>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),
	Yup.  Only to some folk it may not be obvious.  Adding this will affect
	simplicity and efficiency.

>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?
	I should think so.  That was teh gotcha i was worried about.

>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
>description. 
	What was used for current limit?
	(An "rf choke" to "keep the RF out of the transformer" might, by
	accident or design serve the function....)

	regards
	dwp