RE: ARDTSG (fwd)

["Tesla list" <tesla@xxxxxxxxxx>]

---------- Forwarded message ----------
Date: Tue, 9 Oct 2007 12:44:18 -0600
From: S&JY <youngs@xxxxxxxxx>
To: 'Tesla list' <tesla@xxxxxxxxxx>
Cc: crispy@xxxxxxxxxxx
Subject: RE: ARDTSG 

Chris & hopefully others,

I have been using just such a setup for years, and it works very well.  No
trailing arcs, variable break rates down to almost zero & no need for
ballasting of the power supply.  I have reported it to the list before and
advocated its use.  You may be the only other one in the world to give it a
try.

In my setup, I have the primary in series with the MMC.  (In your drawing,
replace the primary with a wire, and put the primary in the center leg in
series with the cap.)  The thought was that the charging pulse would
contribute a bit of energy to the secondary in between the main discharge
bangs.  I don't know if it makes any discernable difference.

Be careful with your angle grinder.  Some have rather sloppy bearings,
causing the rotor to overcome gravity and lift up at higher RPMs.  This can
cause contact with the stationary electrodes - a disaster!  I had to add a
bearing mounted screw that would push down on the grinder shaft.  

You may eventually grow to hate the horrible gear noise of an angle grinder.
I did, and went to a surplus treadmill motor that is very quiet and smooth,
and has no bearing play.

You can "machine" a very good disk by mounting a small grinding stone in a
drill press and putting your rough-sawed disk on an axis, then hand-rotate
the disk against the grinding wheel until it becomes perfectly round.  You
could probably do the same thing with a bench grinder if you kept the disk
perpendicular to the grindstone.

--Steve Y.

-----Original Message-----
From: Tesla list [mailto:tesla@xxxxxxxxxx] 
Sent: Monday, October 08, 2007 9:32 PM
To: tesla@xxxxxxxxxx
Subject: ARDTSG (Was "Spark Gap Sustaining Current") (fwd)


---------- Forwarded message ----------
Date: Mon, 08 Oct 2007 20:46:13 -0500
From: Crispy <crispy@xxxxxxxxxxx>
To: tesla@xxxxxxxxxx
Subject: ARDTSG (Was "Spark Gap Sustaining Current")

In reference to its switch counterpart, I think the new type of spark
gap that was being discussed could be called a Double Throw Spark Gap.
I just finished building mine, and am ordering the parts to finished the
Tesla coil.  I also made a short web page on it ...
http://tangent.cluenet.org/~chules/hv/tesla/dtsg.html

The one that I made is constructed from an angle grinder.  It's mounted
such that the axis of rotation is perpendicular to the base plane and
the electrodes rotate above the angle grinder.  Because I don't have
tools to machine a disc and a propeller gap wouldn't have worked with
the angle grinder, the part that rotates is two G10 bars mounted
perpendicular to each other, with short tungsten rods mounted
perpendicular to the rods at the ends.  There are 4 moving contacts and
2 sets of stationary contacts, each of which can act as its own switch.
The stationary contacts are mounted at 45 degree angles from each other
such that the moving contacts alternate between the two.  Pictures
forthcoming.

Chris B