Re: [TCML] nst

["Phillip Slawinski" <pslawinski@xxxxxxxxx>]

I tried this method on a junk NST I have.  With two holes I was able to gain
10 ma of current.  This was on a 9kV 25mA unit.  Inital measured current
28mA, after holes 38mA.  So it looks like this does work.  Drilling the
holes was a pain though, and it looks very ugly.  By the way, this core did
not have shunts per se, the core was a sort of O I configuration.  There is
a square frame that an I is welded into.

On Mon, Jul 14, 2008 at 9:44 PM, bartb <bartb@xxxxxxxxxxxxxxxx> wrote:

> Hi Bill,
>
> I'm the person who told Doug drilling is not a good idea. I had two main
> reasons in my head when he approached me with this.
>
> 1) Will he drill in the right spot? Who knows how exact the core is placed.
> Easy to accidentally drill through a coil due to being a little off center.
>
> 2) By drilling, the shunts are shorted across for those shunts that have
> been drilled through, and likely, a little sideways due to core and case
> alignment as well as "blind" drilling.
>
> Doug is thinking! How to increase the current on NST's without depotting.
> This is an excellent idea! But because of the placement of shunts in the
> core, trying to drill through the shunt to remove shunt material would be a
> very difficult task. Let's assume he drilled, hit the center of the shunt
> stack, and took out a 1/4" hole in the center of a 3/8" wide shunt stack. He
> may be fine there. He would have removed some material but he would not have
> been able to short all the laminations unless he went in sideways (very
> probable). It actually might work ok in some cases and certainly worthy of a
> try I think. I don't think it's possible to attain the performance as one
> can with shunt reduction during depotting, but it does give a risky
> alternative.
>
> So Doug, if you have NST's growing out of your ears, then I say go for it
> and let us know what you learn from the experience. I don't know of anyone
> who has thought of or tried this. Your in "virgin territory" and that's a
> nice place to be with Tesla Coils and their components.
>
> Take care,
> Bart
>
>
> William Noble wrote:
>
>> a siingle weld on the laminations is OK, but the use of laminations is
>> only partly for ease of manufacture - it is more to get the magnetic
>> properties of the core right and to manage circulating currents - if you
>> just short out the laminations so there is a continuous path for current,
>> you will in effect create a single turn secondary and it will rob
>> efficiencly and cause heat - both of which you dn't want.> From:
>> Gary.Lau@xxxxxx> To: tesla@xxxxxxxxxx> Date: Mon, 14 Jul 2008 19:06:15
>> +0000> Subject: RE: [TCML] nst> CC: > > I'm not sure that a short between
>> laminations would be a problem. I've seen cores built where a welded bead
>> held all of the laminations together. I would be more concerned that milling
>> or drilling might just munge up the nice flat laminations into a mess.> >
>> You lost me on the PVC part.> > Gary Lau> MA, USA>
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