Re: Ballasting a Pole Pig (Revisited)

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: "J. Aaron Holmes" <jaholmes@xxxxxxxxxxxxxxxxxx>

Let me share with you what *I* do, though it's
probably going to make some people point and laugh :)

Though it's terribly lossy, the ballast I presently
use for my TC and Jacob's ladder is just a 20 gallon
plastic garbage can filled with water that's been
doped with several table spoons of baking soda (add to
taste! :D )  Submerged in the can are two copper
pipes, about 6' long each, oriented vertically, with
about 3/16" space between them.  One of the pipes has
a piece of PVC over it.  Raising and lowering the PVC
varies the resistance smoothly from several hundred
ohms down to about five ohms (depends on the water
level and amount of doping, of course).  A PVC "T"
connector with another short length of PVC tube
creates a nice control handle.  Everything needed
(except the baking soda and water) can be found at
Home Depot for around $30.

I like it.

Again, I know it's terribly lossy, however it does
seem to work ok, and can run for quite a while before
the water begins steaming.  Also, operation is nice
and smooth; no big "thump!" noises when things are
brought up, and hence, I suspect, a bit less stress on
transformer insulation.  Down the road, I'll be
experimenting with a hybrid inductive/resistive
ballast, but for now, wholly-resistive does what I
need :)

To contrast with a similar ballast design that I heard
mentioned long ago, wherein the electrodes are
*lowered into* the water, the design above has the
following advantages (IMO):

1) Because the PVC shield is raised to reduce the
resistance, gravity is naturally working to *increase*
the resistance, which means that if you drop the
handle or something else breaks, the power is probably
going to be reduced automatically instead of the other
way around.  Definitely a good thing!

2) Because conduction starts at the bottom of the
garbage can, convection improves circulation of the
water, thereby permitting you to run the thing for
longer.  If you were to lower electrodes into the
water, conduction would begin at the top, and that's
where the heat would tend to stay; it would tend to
heat very rapidly!

I suppose electrolysis effects produce some H and O
while the thing is running, however from the bubbling
I see, I don't think the volumes of gas produced are
sufficient (particularly in my relatively
well-ventilated garage) to create an explosive
atmosphere.  At least I *hope* not!!

aaron


--- Tesla list <tesla@xxxxxxxxxx> wrote:

> Original poster: "C. Sibley" <a37chevy@xxxxxxxxx>
>
> David,
>
> I only have a 15A 220V circuit to play with, and am
> in
> the process of getting the electrical upgraded.  I
> can
> run the setup for longer periods with the welder set
> to a lower current.  But at the lower currents the
> voltage to the pig is essentially zero.  I have
> verified and cleaned all of the hookups.
>
> I'll try one of the other ballast methods and let
> the
> list know what I find.
>
> Curt.
>
>
> --- Tesla list <tesla@xxxxxxxxxx> wrote:
>
>  > Original poster: "David Rieben"
>  > <drieben@xxxxxxxxxxxxxxx>
>  >
>  > Curt,
>  >
>  > It sounds almost like you have a short circuit
>  > somewhere,
>  > as the welder should not be tripping breakers
> that
>  > quickly
>  > under any circumstances. What size is the circuit
>  > breaker
>  > that you're on and how big is your welder? I have
>  > person-
>  > ally never used an AC/DC welder for ballasting a
>  > pig, but it seems to
>  > me that it shouldn't be much different than using
> a
>  > straight AC one.
>  >
>  > Are you sure that you have the welder in SERIES
> with
>  > the in-
>  > put to the pig's LV inputs? Only 25 volts
> reaching
>  > the pig is
>  > certainly not right. I would definitely suspect
>  > either the hookup
>  > connections or the welder itself as the culprit
> in
>  > this situtation.
>  > Try using the 120 volt input winding of an
>  > MOT with its secondary shorted as a temporary
>  > ballast and simply feed
>  > your pig 120 volts and see if you get any
>  > output at all from the pig in this fashion. You
>  > could also use
>  > a 500 ft spool of #12 AWG THNN building wire from
>  > Home Depot or
>  > Lowe's as a ballast with 120 volts input to try
> this
>  > out. If you do
>  > get some output with your pig wired up in this
>  > fashion, then the
>  > problem is most likely that your welder is bad.
>  >
>  > David Rieben
>  >
>  > ----- Original Message ----- From: "Tesla list"
>  > <tesla@xxxxxxxxxx>
>  > To: <tesla@xxxxxxxxxx>
>  > Sent: Sunday, January 08, 2006 10:45 PM
>  > Subject: Re: Ballasting a Pole Pig (Revisited)
>  >
>  >
>  > >Original poster: "C. Sibley"
> <a37chevy@xxxxxxxxx>
>  > >This weekend I did as suggested below and had
>  > >unsucessful results.  With the pig set up as a
>  > Jacobs
>  > >Ladder, and the welder set on the highest power
>  > >setting, I was unable to get any spark from the
> pig
>  > at
>  > >all.
>  > >The problem appears to be the welder taking all
> of
>  > the
>  > >power, input voltage to the pig is only 25V with
>  > the
>  > >welder on and running.  I do not have an AC
>  > Ampmeter
>  > >so am uncertain of the current, but was tripping
> my
>  > >bbreakers after only 1-2 seconds.  Setting the
>  > welder
>  > >at a lower rating would allow the breakers to
>  > remain
>  > >on, but with essentially no voltage to the pig.
>  > >One posibility, is that my welder is an AC/DC
> unit,
>  > >and must have additional circuitry over a basic
> AC
>  > >unit.  Perhaps there is some PFC or something
>  > >interfering?
>  > >Imsnip.........