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Re: Grounding



Original poster: "Jim Lux by way of Terry Fritz <twftesla-at-qwest-dot-net>" <jimlux-at-earthlink-dot-net>

You mean you want useful advice on setting up an experiment(s) to find out
for yourself (which, by the way, would be a great service to the list)?

I presume you have some sort of coil to test with.

Assuming here a "table top" type coil (i.e. not a polepig powered six foot
thing throwing 30 foot arcs)

Set up a test area outdoors (or in a very large room) so that the effect of
walls and ceiling can be eliminated.  As a guess, I'd say the nearest
object should be 5 times as far away as the largest dimension (probably the
height) of the coil.

Run a series of tests running the coil at various heights above "real"
ground, grounding the secondary to a decent ground rod (if outdoors) right
in the center under the coil. Soak the soil down real well so it is a good
conductor.

Run a series of tests with the TC sitting on a table (preferably an
insulator, like a big plastic barrel with a sheet of plywood on top.  Maybe
a couple of sawhorses and plywood would do.  Put a metallic ground plane
under the coil, on top of the table.  Make a series of tests with different
size ground planes, or with different materials for the ground plane (sheet
metal, chicken wire, aluminum foil, etc.)

The key will be some way to make quantitative measurements.  Calibrated
spark length to a grounded rod is one idea, and fairly easy to implement,
especially if you have a "breakout point" on your top load.  You might also
measure current and voltage (and power, if you can) to the transformer.

For an interesting test, although it will require some fiddling around, you
can try to run your coil upside down or sideways, with a groundplane or
counterpoise some distance away.

You might also try running it in normal position, with a movable wall (say,
some chicken wire on a piece of plywood stood vertical, or some of that
foil covered foam insulation) that you move closer and farther away.

You can run a series of tests with different types of ground wire (i.e. 1
thin wire, 1 thick wire, lots of thin wires in parallel, spread out, lots
of thin wires in parallel, bunched together, etc.)



Tesla list wrote:
> 
> Original poster: "by way of Terry Fritz <twftesla-at-qwest-dot-net>"
<Kidd6488-at-aol-dot-com>
> 
> Ok, pressed for time, I decided to make this year's science fair
question: "How
> does grounding a Tesla coil affect its performance?" I am in need of sources,
> so I turned to you guys. I need as much, juicy, detailed, somewhat lengthy,
> information about what exactly does grounding a coil do, and any other
> information about grounding coils.
> Links really won't help much, because we can only use one internet source.
> 
> Thank you in advance,
> ---------------------------------------
> Jonathon Reinhart
> hot-streamer-dot-com/jonathon