Re: 15kV Neons and a pole oinker. (fwd)

---------- Forwarded message ----------
Date: Tue, 21 Apr 1998 09:01:49 -0700
From: Jim Lux <jimlux-at-earthlink-dot-net>
To: Tesla List <tesla-at-pupman-dot-com>
Subject: Re: 15kV Neons and a pole oinker.

> From:  J. Day [SMTP:jon-at-axionet-dot-com]
> Subject:  15kV Neons and a pole oinker.
> I just got my hands on a pair of 15kV/30 mA neons.  If hook them up
parallel, then I will get 60mA... I am almost sure of that.  I remember
reading a message that said that two transformers must be "in phase" before
the current will double.  If they have the same line level input, then
won't this be automatic?  (the two transformers are identical

Providing you hook the matching output terminals together. Presumably
you've got a NST with the HV bushings at either end, with the AC power in
on one end. Set the two NST's next to each other with the 110V AC
connections at the same end. Wire the bushings that are at the same end to
each other. Make sure that the AC connections are also parallel. 

You'll know if it is wrong, because you won't get any HV output, but the
transformers will get warm because you have effectively shorted the output.
These are current limited, so that won't hurt them, though..

> Is it true that these transformers don't need current limiting, as it is
built in?


> What about for Jacobıs ladder?  I want to try out the Jacobıs ladder for
fun, and don't want to ruin my xformers before they get a crack at Tesla!

You shouldn't have a problem with that, and it provides a handy test of the
phasing, as well. 
> And one last thing, out of curiosity....  how many 15kV neons does it
take to get the power of a pole pig?  (and where in the world do you get
these monsters?  ... I hope you don't steal them off the pole in my block,
as my power would go out!!!  and that means no tesla!  heheh)

You buy them from a utility transformer dealer or find them surplus. A few
hundred bucks and some significant shipping costs (they weigh a bunch) will
get you one. Names of dealers can be found in back posts on this list.
Surplus is a real challenge in California because of environmental
regulations, except if you find a private party willing to sell you one.

Pole transformers are rated in kVA, with 10 being a sort of lower bound. A
15 kVA transformer with a 14.4 kV HV winding (typical) would put out about
an amp at rated power (15 kVA/ 14.4 kV = 1.?? Amp). It would also draw
about 60-65 Amps from the 240 Volt side. Pole transformers are available
with myriad HV voltages from 5 kV or so, on up.  In Tesla Coil use, you
could probably run the pole transformer at substantial overloads (2x, 3x?)
because they are designed with a lot of margin: it has to sit out in the
sun in the desert for 40 years with no problems.  

Pole transformers have NO current limiting, and even the magnetizing
current (no load) will dim the lights pretty noticeably when you hook it