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Re: Here pig pig pig
to: Bill
The neutral connection is not used. You will note the two copper pri
straps attach to the neutral. Remove them and connect them together. Then
220 v is fed across the two outer strap connections, ie, you are now
feeding the 220 across two separate 120 v windings that are connected in
series. On the HV output side, connect one of the HV outputs to the case
of the xmfr with a 10 AWG wire. Also connect your ground feed to this same
connection. This will give you a single ended output and the xmfr core is
ground. For even better results, now remove the entire pig from the oil
and drop it into a square steel tank: 1/8 inch x 14 inch x 14 inch x 15
inch tall (for 10 kva xmfrs). When the case is manufactured leave a 5/8
lip all around the top. Apply a gasket and top the lid with 1/4 inch type
LE phenolic plate. Bring your 220 v, ground, and HV connections through
this insulating lid. For the HV use a 4 inch long x 1/2 inch dia plastic
tube and use a quality HV cable (neon sign cable is fine) for the output.
Slowly fill the xmfr with oil using the siphon method. We short the sec
winding and apply 500 watts of pri power thru a variac to keep the xmfr
warm and help to outgas air bubbles more effectively. After filling you
will have a compact, recased "pig" with oil that weighs around 125 lbs
total. Affix to a small plywood dolly on caster wheels and you have a nice
somewhat portable HV power supply for TC experiments.
I have also noted on the list a few experimenters who have stated they were
bitten by neons two or three times. If this is your experience you should
ditch the pig fast -- it will not be forgiving and will fry you instantly.
Anyone bitten by a neon more than once should never be playing with pole
xmfrs. These are extremely lethal and completely ignorant of your desire
to stay alive.
Good luck and be careful.
Your RF choke was fried because you failed to use varisters before and
after the filter. They will clip the high level transients before they can
enter the filter. Also, we usually use a small "hash" choke on the
transient side of the RF filter to clip the higher level RF spikes before
varisters and then filtering occurs.
DR.RESONANCE-at-next-wave-dot-net
----------
> From: Tesla List <tesla-at-pupman-dot-com>
> To: tesla-at-pupman-dot-com
> Subject: Here pig pig pig
> Date: Saturday, September 19, 1998 10:10 PM
>
> Original Poster: "Bill the arcstarter" <arcstarter-at-hotmail-dot-com>
>
> Coilers,
> Well I am in possession of my pig! No - it didn't weigh a mere 125 lbs
> as advertised. The true weight is 300 lbs + 25 for the pallet it was
> strapped to!
>
> I am now famous at work for having a pole transformer delivered to the
> loading dock! I came back with my pickup and grabbed it (lined up the
> powered loading elevator with the bed of the truck and pushed it in
> using a pallet jack).
>
> Just tonight I completed welding a cable winch onto the end of my boom
> arm - and was able to use said instrument to get the transformer off the
> truck, onto the ground. :)
>
> The transformer appears to be BRAND NEW - no rust, white paint, the
> wire lugs are tight down and don't appear to have ever clamped a cable.
> The can is roughly 16 inches in diameter and 28 inches tall. The input
> insulator is over a foot long which places the top of the insulator at
> about 41 inches off the ground! It isn't small or portable and is not
> quite what I expected.
>
> Total bill was $94 + $70 s/h. Not a bad deal. I will get the relevant
> addresses/URLs for anyone else interested in adopting such an electric
> animal. I also have yet to pursue those mini-pigs in the local scrap
> yard.
>
> There is no top access plate so I don't think it has a tap switch. I
> can take the entire top off (including the input bushing) which I will
> do to inspect the insides.
>
> There is what appears to be a pressure blow-off port at the top of the
> can. (a spring-loaded pull-ring)
>
> It contains the traditional three lugs for 120-0-120 connection, and
> the '0', or neutral lug is also bussed to the case of the transformer
> (this is removable). There is also a separate lug welded right to the
> case.
>
> I'm going to have to find some sort of wheeled platform for this thing
> to sit on. Either that or I'll put wheels on the pallet and call it
> done!!
>
> I was thinking about how to power the darn thing... I have a 240 v 28
> amp variac and various limiting devices (including a welder). But the
> problem is that if I use the variac - what becomes of the neutral
> connection on the pig? I can't connect it to the neutral bus - since if
> I did - then one 120 volt primary of the pig would always see a full 120
> volts (from N to Hot). Also - since I have only one HV output and the
> other side is connected to the case - I'd really need to keep the case
> grounded and connected to neutral. The only solution I see is to use an
> isolation transformer between the variac and the pig. This should allow
> me to tie the pig's N to system N/ground, and power the pig's 12v lugs
> off the isolation transformer.
>
> It just so happens that I have a 20 amp 240v toroidal 1:1 isolation
> transformer!
>
> Does anyone think I should break the pig's N-to-case link, tie the
> pig's case to a good RF ground, and then tie the pig's N to the power
> neutral? I think that might be the best plan.
>
> Oh - I depotted our 37 amp line filter which the tesla coil killed. It
> is hard to tell but it looks like the RF arc'd from one hot wire,
> through the potting tar, to the case. That tar just barely became soft
> at 350 degrees (in a toaster oven). I would think that the heat time to
> depot a large neon would be at least 12 hrs since this 4x3x1 inch filter
> took over 2 hrs to melt and there wasn't any iron to heat either!
>
> More later. Comments invited.
>
> -Bill
>
>
>
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