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[TCML] VB: First light

Yes Steve,
it is an underground bomb shelter, formed as a tunnel. It is huge, two
stories, made to shelter 1800 people, but limited in height and width. I
will move the flourescent lighting from the wires that hangs from the roof,
to a position closer to the walls, to gain some space for the coil. And I
will experiment with toroid height and the breakout point (if I need one). 

The coil design is pretty much standard for the size, I think. ARSG is a 300
mm FR4 disc, on a 2.2 kW 3 phase 3000 rpm motor. Six flying 3/8 inch
tungsten electrodes in brass bolts. Stationary electrodes are 1/2 inch
tungsten, clamped in very large Al cooling fins (7 kg each). VFD motor

Tank cap is a MMC, based on the usual CornelDubilier caps, 18 in series, 36
such strings in parallell, for a total of 300 nF. The caps are housed in
cable channels. It was an insane project to solder these together, will not
do it again, I hope. Primary is 1/2 inch Cu tubing, tapped at a little less
than four turns. 

Secondary form is a 315 mm polypropylene tube, wound with 1.06 mm Cu, about
900 turns. Main toroid is 315 mm vent duct, outside diameter 1.5 m, height
above floor about 2.2 m. 

The 12 kV HV transformer is home wound on a 55 kg core, in an oil tank. Tha
ballast core is very large, about 130 kg with 2 x 12 mm air gap, with six
switched taps for a current of 10 - 50 amps at 400 V. The ballast is very
well behaved and soft starting, I dont have a variac so that is important. 

So far I have only run the coil at half power, for very short runs. I have
to move the lighting fixtures before I can allow the coil to strike
sideways, so I have no idea of the coils potential at the moment. 

Here are some rather badly lit photos:


Stockholm, Sweden

Is that underground?

On Sat, Dec 8, 2018, 12:30 PM G Hunter via Tesla <tesla@xxxxxxxxxx wrote:

>  You may be able to crudely adjust the breakout angle by changing the 
> height of the toroid.  I found that if I placed the toroid very close 
> to the top turn of the secondary, the streamers tended to curve 
> downward.  If I raised it a bit, they broke out horizonally.  If I 
> raised it a lot, I
> serious top turn corona and the streamers tended to curve upwards.  By 
> experimenting with toroid height and breakout point location, you may 
> be able to reduce ceiling strikes.  This is only rough adjustment of
> Some streamers are just wild and there's no controlling them.
> Greg

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