Garage Physics

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Gregory Hunter by way of Terry Fritz <twftesla-at-qwest-dot-net>" <ghunter31014-at-yahoo-dot-com>

A physics teacher from Middle Georgia College came by
Thursday night, and he brought three of his students
with him. He told me was teaching them about magnetic
fields, but was having a hard time illustrating it. We
agreed a Tesla coil would make a darn fine demo of
magnetic coupling! The prof is not a hardware guy, and
he makes no apology for it. His forte is classical
physics and the underlying math. He is not a gadget
guy, and doesn't want to be. Even so, he and his
students very much enjoyed seeing my gadgets, and I
got a hoot out of showing them.

After a short lecture on Nikola Tesla and his various
contributions to the world, I ran the little 4" x 24"
coil for them using the twin MOT supply. It obliged by
putting on a helluva show--multiple loud, snappy
streamers out to 4 feet or so. I performed the trick
with a 6" clear light bulb on a long stick of PVC
pipe. The purple glow inside was excellent. I also
walked around the garage with a 48" florescent lamp
glowing in my hand, demonstrating wireless power
transmission. Later, I laid the 48" tube lamp atop the
toroid and lit up the coil. The tube flickered and
sparks issued from each end, as expected. However,
after a few seconds we got something unexpected. Hot
little arcs developed at the points where the tube
touched the toroid, and a pinkish glow began to spread
down the length of the tube--like a bar of iron being
heated with a torch and starting to glow cherry red. I
quickly shut off the coil and we all examined the
tube. The glass showed tiny fractures where it touched
the torus, and the glass was permanently discolored a
pinkish/orange hue for several inches, starting from
the points of contact. Hmmm. Weird.

Next, I fired up the 6" x 30" system driven by the
11.5KV pole xfmr. I had put my big pool toy toroid on
top to get longer sparks. I first ran the thing at
only 240v/8A input. Performance was stellar--fat blue
sparks in the 5 to 6 foot range (estimated)--the
college kids wanted more. I opened up the arc welder
ballast to 28A, and the resulting storm of streamers
was absolute bedlam. In the confines of my closed up
garage, the noise and light was a bit overwhelming for
them--sort of like a big firework star shell that
bursts a little too close to the spectators! The
sparks were hitting my work bench, the ceiling, the
floor, the walls, storage cabinets, etc., etc. The
safety gaps were snapping like firecrackers. The big
sucker gap sounded like an un muffled chain saw. The
air reeked of Ozone and NOx! All I needed to complete
the picture was a hulking cadaver laid out for
re-animation!

I really enjoyed my brief hour as a physics teacher.
I'm glad the kids got to see what happens when theory
is put into practice. I hope the Tesla coil demo was a
positive influence. Who knows--maybe some of them will
go on to become hardware types--mirror grinders,
satellite builders, particle accelerator geeks, etc.

Best Regards,

=====
Gregory R. Hunter

http://hot-streamer-dot-com/greg

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