Re: [TCML] HV Transformer Winding

[bartb <bartb@xxxxxxxxxxxxxxxx>]

The LV end is always towards the core in a hv winding. Say the inside 
winding begins at your left and wound along the core to the right for 
one layer cw. When you flip the secondary 180 degrees and insert it back 
onto the core, the LV end is still connected to the core except now the 
winding begins at the right and is wound to the left in a ccw direction 
which changes the polarity. It's "where" the LV end begins in relation 
to the winding and the core. But that example is only the parallel 
winding aspect in relation to the core. The other aspect is that it is 
multi-layered so the perpendicular aspect begins to take shape as more 
and more layers are wound.

In the end, the polarity of the two hv coils can either aid or oppose, 
and thus flipping one of the hv windings on the bobbin is all that is 
needed to match the primary winding direction regardless if the primary 
is wound cw or ccw. Which is why I stated to flip one of the hv bobbins 
and test.

Take care,
Bart


Chip Atkinson wrote:
> I think the deal with flipping coils on the NST coil hinges on where the
> inputs and outputs are connected after the flip.
>
> If you have a flat coil and flip it, you implicitly leave the input end at
> the center and the output at the outside.  When you flip a solenoid, you
> don't implicitly flip the contacts, they stay at the right or left end.  
>
> With a NST coil, the input (or output) is at the center of the coil and
> the thus the input is *not* flipped as is done with a solenoid an the
> polarity will be reversed.
>
> Chip
>
> On Fri, 24 Apr 2009, bartb wrote:
>
>   
> > Hi Jim,
> >
> > Flipping one of the hv coils in an NST will certainly change it's 
> > direction (multilayer coil). I would expect the same with the 
> > transformer Phil is building. This is why when re-assembly of an NST is 
> > performed, getting the hv windings oriented correctly is a must. 
> > Consider a flat primary coil and flip it (winding direction 
> > perpendicular to the center changes).
> >
> > Bart
> >
> > Jim Mora wrote:
> >     
> > > Hi Bart,
> > > Flipping a coil bobbin does not change its winding direction (counter
> > > intuitive). Test it with a spring of scrap piece of wire. Aren't neon
> > > transformers wound in opposite directions (similar core scenario)?
> > > Jim Mora
> > >
> > > -----Original Message-----
> > > From: tesla-bounces@xxxxxxxxxx [mailto:tesla-bounces@xxxxxxxxxx] On Behalf
> > > Of bartb
> > > Sent: Thursday, April 23, 2009 5:38 PM
> > > To: Tesla Coil Mailing List
> > > Subject: Re: [TCML] HV Transformer Winding
> > >
> > > Phil,
> > >
> > > I'm in the same boat as Finn here. I'm thinking the windings are wound 
> > > in opposite directions myself, but I'm not certain. I expected that you 
> > > would be winding the secondary coils on individual bobbins at first and 
> > > simply sliding them onto the core (in which case you could just test it 
> > > flipping one of the bobbins). But are you winding the secondary coils on 
> > > the core itself? If so, then Finn's suggestion is certainly the test to 
> > > perform.
> > >
> > > Take care,
> > > Bart
> > >
> > > Finn Hammer wrote:
> > >   
> > >       
> > > > Phil Tuck skrev:
> > > >     
> > > >         
> > > > > I have posted this on the 4hv.org forum, but as I started the project on
> > > > > here I will include it on here as well.
> > > > >
> > > > >  
> > > > >
> > > > >   
> > > > >       
> > > > >           
> > > > Phil,
> > > >
> > > > I have been thinking long and hard, but everytime I am close to a 
> > > > conclusion, my head starts to explode, and I have to start over.
> > > > So I will advice you to do what I would do myself:
> > > >
> > > > Energize the primary, and make a couple of nice test windings with 
> > > > some of the scrap insulated wire you have stashed away for this purpose.
> > > > You only need some 5-10 turns to settle the matter, really.
> > > >
> > > > Hope this helps,
> > > > Cheers, Finn Hammer
> > > > _______________________________________________
> > > > Tesla mailing list
> > > > Tesla@xxxxxxxxxxxxxx
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> > > >     
> > > >         
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> > >   
> > >       
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> >     
>
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