grounding and gaps
Subject: grounding and gaps
From: richard.quick-at-slug-dot-org (Richard Quick)
Date: Sun, 31 Dec 1995 01:17:00 GMT
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> I am soon to be finishing my grounding system per RQ's
> instuctions as I have time now. Can I use thick copper braided
> strap to connect from ground cable to Tesla coil end ? The
> cable is pretty stiff and is already in the way in the small
> confines of my allotted "lab".
It has been pretty much determined by us that braided strap of
any type should not be used anywhere in the RF side of the coil
system. This would specifically include the ground path. I would
suggest using a flat strap conductor to make this run. Something
like four inch wide aluminum or copper flashing would be ideal.
The smooth strap can be laid flat on the floor and held down with
a few strips of duct tape.
> Is it aceptable to use a sort of ground bus bar setup at my
> bench and then use braided strap to connect to my coil for
> convienance sake?
I would go with flat strap or "flashing".
> Also do I only want to use this ground as a sort of RF dump or
> can I also use it for my neon x-formers common side? My house
> is 35 years old and the lack of separate ground wires in
> receptacles is being dealt with gradually. Since the neutral is
> connected to the ground at the load center is that adequate for
> my power supply or do you recommend a different approach?
Keep your 60 cycle neutral and your RF grounds electrically
isolated. Connecting them allows a path for RF to enter and
energize the 60 cycle house wiring. This separation line is
usually drawn at the step-up transformer, in this case the neons.
Bring in your normal 60 cycle wiring; whether it is 120/neutral
or 120/120 (240 volt service) and run this to the primary on the
step-up transformer. The transformer case and core will also
require a ground connection; ground the case/core to your
dedicated RF ground. If you ground the case/core back to the 60
cycle neutral you have opened a path for the RF to bleed over to
the house wiring. The primary winding on the step-up transformer
is insulated from the case/core.
> I have also pounded in a new 8 foot copper clad rod for house
A wise and healthy precaution.
> Also time for a stupid question. Could it be worth while to
> pulse primary x-former current? Would that raise frequency of
> secondary output and alleviate the need for such exotic
> mechanical spark gaps? Would it not be possible to adjust
> oscillations to help tune secondary? Just some questions from a
> learning coiler.
If you are running neons you don't need exotic rotary gaps. Get
the cylinder static gap plans and build one or two of those. You
will be very pleased. The other stuff sounds like more trouble
than it would be worth.
> PS I read something about being able determine(resonance?) by
> the sounds the (spark gap?) makes. From a squeel to a growl I
> believe. Could you please elaborate? Thanks again, Mike
This only applies to static gaps. If there is a rotary gap in the
tank circuit this does not apply:
The frequency of firing and the tone of the simple static gap
will provide some indication of the tune. A gap that sounds
really rough and growly is telling you your coil system is having
some problems. A gap that sounds smooth: firing rapidly, evenly,
and high pitched, indicates a coil system that is effectively
processing RF energy. The ability to use this information
requires a bit of experience, but, it is one area that even a
novice coiler can begin to pick up with the first throw of the
switch. Listen to your spark gaps.
... If all else fails... Throw another megavolt across it!
___ Blue Wave/QWK v2.12