RE: [TCML] pig Jacobs (don't totally blow off resistive ballasting)

[sparktron01@xxxxxxxxxxx]

Aaron

I used a virtually identical Rballast years ago using
baking soda, and a windshield wiper motor+lead
screw combo to side a 1/4" SS plate between two
1/4" fixed SS plates wired in parallel.  Plates slid in
a 2" x 8" salt treated wood frame.  Worked absolutely
flawlessly (at up to 60A -- NO TYPO @ 240VAC).

Railroads used liquid rheostats in early electric 
traction, and with radiator type electrolyte cooling
and natural convection cooling  would be dam**
near indestructible at 100's of kVA passing; at a
FRACTION of the cost of a high power
inductive ballast.  Wire and steel costs have lately
skyrocketed, and this neatly circumvents the cost
issue.

Regards
Dave Sharpe, TCBOR/HEAS
Chesterfield, VA. USA

 -------------- Original message ----------------------
From: "J. Aaron Holmes" <jaholmes@xxxxxxxxxxxxxxxxxx>
> If the element is immersed in water, even if it fails
> "open", it may not actually be completely "open"
> because of the water.
> 
> ...which brings me to another suggestion for a
> ballast:  My first pig ballast was just two copper
> pipes held in parallel by nylon bolts and immersed in
> a plastic garbage can full of water.  I put a PVC
> sleeve over one of the pipes which could be raised or
> lowered to vary the resistance, then doped the water
> with baking soda until I'd achieve the desired
> resistance range.  It worked great and allowed for
> very smooth control, albiet farily lossy.  Since the
> PVC had to be raised to reduce the resistance, gravity
> would naturally turn the power down if I let go of the
> control handle (A PVC "T" joint with another small
> section of PVC sticking off the side).  Also, this
> meant that the heat production was always near the
> bottom of the garbage can, allowing for plenty of
> convection cooling.  It took quite a while for the
> water to get hot, even with many kVA's involved.
> 
> So, despite the lossiness of resistive ballasting,
> it's still hard to beat for simplicity and smoothness
> of control.  And also (probably) cost.  Check the
> prices on 500ft rolls of #10 wire these days ... :-(((
>  Then compare to the prices of a few short sections of
> PVC, water pipe, and a plastic Rubbermaid (or similar)
> garbage can.  I think I spent about $20 total
> (although I already had the PVC).
> 
> My ballast these days is a big variac which I lucked
> into at a great price.  If you want to build a big
> variable inductor for cheap, however, Goodle for
> "slide choke" and "tesla" and you'll get lots of good
> hits, I'm sure.
> 
> Cheers,
> Aaron, N7OE
> 
> --- david baehr <dfb25@xxxxxxxxxxx> wrote:
> 
> > 
> > Yea, 50+ amps is high for a JL , but, if ya wanna
> > see the big , thick plasma ( ? ) , ya gots too :-)
> >  
> >           Oh, if the element fails , this would be
> > an 'open' circuit , woulnt it ?? it would just turn
> > off ?  
> >  
> 
> _______________________________________________
> Tesla mailing list
> Tesla@xxxxxxxxxxxxxx
> http://www.pupman.com/mailman/listinfo/tesla

_______________________________________________
Tesla mailing list
Tesla@xxxxxxxxxxxxxx
http://www.pupman.com/mailman/listinfo/tesla