[TCML] Bombarder transformer grounding
sfxneon at aol.com
sfxneon at aol.com
Wed Jan 13 21:31:13 MST 2010
I have an old 7.5 kVA SOLA bombarder with slide choke that I'm using on my
8" coil and it has worked very well so far, although it is center tapped
Bombarders are not as robust as pole pigs when it comes to overvoltage or
continuous duty at maximum ratings because they lack the oil for insulation
and cooling, but can be pushed way beyond their ratings for short periods
of time. (Some of the newer ones like my 15 kVA neon bombarder are now
potted in asphalt.) If the choke gets hot during extended runs, use a fan to
help keep it cool. It should make a great Tesla coil transformer and
Most older bombarders were wired with the HV center tapped to ground
(between the two HV windings), but most all have a floating secondary now, which
reduces the chance of flashback into the vacuum manifold. Yours is probably
floating if it's less than 20 years old or so. Just measure the resistance
from the HV posts to ground to find out. A safety gap at the transformer
will probably work just fine to protect it from overvoltage.
I think I would connect the bombarder's case and core to the mains ground
and not the TC ground to be safe.
Special Effects Neon
In a message dated 1/13/2010 8:16:03 A.M. Central Standard Time,
makinglightning at comcast.net writes:
I have a Voltarc/Hyde (Willick Engineering) 30KV 250ma 7.5KVA bombarder
transformer that I am planning on using for a teslacoil.
It comes with a big slide choke.
>From talking with an engineer at the company, it sounds like neither the
primary or the secondary are grounded to the core at all. The thing looks
like 2 big coils wound over the primary. The core is just a big rectangle
with the primary and secondary on the same side. I am guessing that the
secondary winding starts from the outside of one coil, goes down to the
middle, near the primary, hops over to the inner side of the other coil,
then would back out.
I am wondering how I would hook up the grounds on a Terry filter and other
parts of the system. It is not the same as a neon transformer where the
windings are connected to ground on one end. Right? Do I use just one leg
a Terry filter?
Which ground would I hook the core of this thing to?
I would like a clear picture of how the whole thing should be hooked up
how the grounds should be hooked up to things here.
I know it is not in oil like a pig. But with a big terry filter should it
hold up better than a neon transformer? Then again, it is not potted. It
sure looks beefey. Overall it is 19 x 15 x 10 and weighs an awefull lot.
counting the terminals. What is the concensus here, should I use this for
I thought I remember someone here on the list using one of these on a coil
More information about the Tesla