Re: [TCML] multiple miniature transformers

[DC Cox <resonance@xxxxxxxxxxxx>]

You can also get a pig and recase it which is what we do for all our high
power supplies.  Total weight of a recased 10 kVA 14.4 kV unit, with oil, is
around 130 lbs.  I mount them inside 17 x 17 x 18" steel tanks with a 1/2"
lip all around.  we weld up the tanks using standard 10 Ga. steel plate,
1018 CRS.

I use a 1/4" phenolic plate for the top to run the 220 in and HV out.  We
usually connect one of the bushings to case ground and core ground as well,
so it's a "single-ended" output.  Output is via neon silicone white GTO wire
as the current is 1 Amp or less.

A series reactor allows you to set the power level at anything you need.
With our 60 nF cap coils we run around 8.5 kVA and with our 100 nF caps we
run around 12 kVA, sometimes up to 15 kVA if we need a really large, extra
hot, fat spark.

Also, the pole xmfrs in oil are much more durable than the NSTs and require
a very simple filter circuit, usually an air core choke a small resistor
network for effective protection.

Dr. Resonance




On Sat, Nov 14, 2009 at 6:49 AM, David Rieben <drieben@xxxxxxxxxxx> wrote:

> Hi Conor,
>
> Personal experience has shown me that a typical (Jefferson)
> 15/30 NST weighs about 23 lbs, so you (and your friend) are
> toting a bit more than 120 lbs if you're picking up eight in one
> "cluster", plus the weight of your cart - probably closer to 200
> lbs. total. That would explain it "being too much for one man
> to handle" ;^\ My 5 kVA, 19.2 kV "piglet" just tips the scales
> at 180 lbs. and I can pick it up all by my lonesome, although
> I sure wouldn't want to go very far with it!  :^0 Still, as others
> have stated, when you start making an NST farm of that many
> transformers, it becomes more practical to just get a pig.
>
> David Rieben
>
> ----- Original Message ----- From: <ConorPerry@xxxxxxxxxxx>
> To: "Tesla Coil Mailing List" <tesla@xxxxxxxxxx>
> Sent: Thursday, November 12, 2009 4:49 PM
> Subject: Re: [TCML] multiple miniature transformers
>
>
> I found a good source for NSTs in Craigslist and took advantage of it.
>> There was quite a stack to dig through, but I found a set of 8 matching NSTs
>> and bought the batch for $100.  They are 30mA @ 15,000volts (450va). They
>> are setup as two sets of 4, double stacked on a wheeled cart.  It's too much
>> for one person to lift, but easy for two people, so probably around
>> 100-120lbs.  I've run it at 4.5kva on a jacobs ladder.  Still gathering
>> parts for a larger Tesla coil.
>>
>> Wish I could find more 120mA @ 12,000volts monsters like I use on my
>> little coil.
>>
>> CP8071
>>
>>
>> ----- Original Message ----- From: "Neal Namowicz" <neal@xxxxxxxxxxxxxxxx
>> >
>> To: "Tesla Coil Mailing List" <tesla@xxxxxxxxxx>
>> Sent: Thursday, November 12, 2009 6:51 AM
>> Subject: Re: [TCML] multiple miniature transformers
>>
>>
>> This is definitely one I have a little experience with. I started
>>> accumulating nst's a while ago, and then began tying them together. At the
>>> moment, I'm up to 6, 9kv/30ma. I have them mounted on a 2' x 2' platform
>>> with casters. As my daughter's boyfriend and I were lugging it up the
>>> basement stairs for halloween, I too wondered why I just didn't get a small
>>> pig. However, there's still the issue of current control that I don't have
>>> to deal with, as I would with a pig. I would stick to using my variac,
>>> rather than switching them on individually, too. I prefer to ramp the power
>>> up slowly, just in case. I'm only using a safety gap for them at the moment,
>>> but I try to be conservative and not push them beyond 80-85% on the variac.
>>>
>>> Neal.
>>>
>>> ----- Original Message ----- From: "Paul Brodie" <pbbrodie@xxxxxxxxxxxxx
>>> >
>>> To: "Tesla Coil Mailing List" <tesla@xxxxxxxxxx>
>>> Sent: Wednesday, November 11, 2009 12:33 PM
>>> Subject: Re: [TCML] multiple miniature transformers
>>>
>>>
>>> Wouldn't 10 neon sign transformers and associated equipment be just about
>>> as bad as lugging around a pole pig or maybe even worse?
>>> Paul
>>> Think Positive
>>>  ----- Original Message -----  From: Chris Rutherford
>>>  Hi All,
>>>
>>>  A couple of years back I made a TC powered by 4 parallel NSTs,
>>>  providing 1KVA, which worked reasonably well.  I was thinking about
>>>  extending the idea using 10 larger (identical) NSTs to provide 10KVA.
>>>  I would individually protect each NST using something like a Terry
>>>  filter, and also place a switch on the mains side of each transformer,
>>>
>>> _______________________________________________
>>> Tesla mailing list
>>> Tesla@xxxxxxxxxx
>>> http://www.pupman.com/mailman/listinfo/tesla
>>>
>>
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>
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