RE: [TCML] Homebuilt Transformer - Can you add shunts?

["Phil Tuck" <follies@xxxxxxxxxxxx>]

Hello Bart, everyone.
Thanks for responding. Now I think about it aren't you meant to have just a
single gap in the magnetic circuit ( i.e.: in just one leg) ?
With my cores (Two pairs of UU's, one pair on top the other at the bottom) I
would need to add 8 plastic shims to go between all the faces (2 x centre
legs and 4 x outside legs). 
I'm wondering if this is interrupting the magnetic path a bit *too much*
-even using thin plastic. 
Milling just two legs shorter on one side, and thereby leaving the magnetic
path complete on the un-milled legs is not an option - I have the necessary
gear but there's no way I am doing that!

At present the secondary is wound over the primary on the centre leg,
whereas I'll go for a secondary on each outside leg centre tapped. This
means the gaps in all the legs will be inside a coil so that might help
matters a bit.

Regards

Phil
www.follytowers.co.uk/tesla

     



-----Original Message-----
From: bartb [mailto:bartb@xxxxxxxxxxxxxxxx] 
Sent: 26 March 2009 03:05
To: Tesla Coil Mailing List
Subject: Re: [TCML] Homebuilt Transformer - Can you add shunts?

Richie used an air gap. This should be possible also with your core 
type. This is probably easier than trying to insert shunts as a magnetic 
leakage bypass with your particular core shown. Lot's of measurements 
are needed until you find the amount of leakage current needed for 
desired regulation. I think probably a simple air gap will be best with 
this core of which you can do by inserting a thin sheet of poly (or 
layers of) at the joining of the two halves.

Take care,
Bart

Phil Tuck wrote:
> Hello.
>
> I am in the process of rewinding a transformer from a UK RADAR set. A
> drawing of the core with sizes can be seen here 
>
>  
>
> http://homepage.ntlworld.com/follies/tesla/radartransformer.html
>
>  
>
> Eventually it will be a 2 to 3 Kva unit   ( originally it was 2Kva 8.25 kv
@
> 250 m/a with  AWG 14 on the primary & AWG 24 on the secondary)
>
> Before I start finalizing turns etc, I wondered can I introduce a magnetic
> shunt to limit the shorted current, like NST's use, and thus avoid having
to
> use a Ballast?
>
> If so would I just need to introduce some packing between the jointing
faces
> ?
>
>  
>
> Richie Burnett has done a similar thing with some inductors to stop
> saturation at 
>
> http://www.richieburnett.co.uk/parts2.html#ballast
>
>  
>
> Looked at a few other webpages on homebuilt transformers but none seem to
> use this method for a transformer though, but I thought this was the same
> method employed by NST's
>
>  
>
> Thanks
>
> Phil
>
>  
>
>      
>
>  
>
>  
>
>  
>
> _______________________________________________
> Tesla mailing list
> Tesla@xxxxxxxxxxxxxx
> http://www.pupman.com/mailman/listinfo/tesla
>
>   


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