RE: ARDTSG (fwd)

["Tesla list" <tesla@xxxxxxxxxx>]

---------- Forwarded message ----------
Date: Tue, 09 Oct 2007 14:04:29 -0500
From: Crispy <crispy@xxxxxxxxxxx>
To: tesla@xxxxxxxxxx
Subject: RE: ARDTSG

Yeah, I think you mentioned this on a thread a few months ago, I had
forgotten about that.  I hope that others will give this a try too ...
looking at many ARSG designs, some would be able to be adapted very
easily.  Another new thing I'm trying is the static gap mentioned in
earlier posts with this thread to try to pulse power at a higher level
to overcome dormitory wattage limits.

Putting the primary in series with the tank cap probably wouldn't do any
harm, but I doubt it would do much good either.  Any amount of energy
contributed to the secondary during the charging pulse would probably be
completely lost before the actual "bang".  In this way, your design
might actually be slightly less efficient, but as you say, I doubt it
would make a discernible difference.

Thanks for the warning about the angle grinder, but mine doesn't seem to
have that problem.  Also, my spacing between rotary and stationary
electrodes is fairly large to allow for somewhat sloppy tolerances due
to my lack of proper tools.

The angle grinder is noisy, but I have it mounted in a structural foam
chest which acts as a shield for noise and particles.  I know that other
motors would probably be better, but I don't have much money to spend.
The angle grinder was $5 on ebay - can't beat that :)

Your method of making a disc is definitely good, but again, I don't
really have the tools.  My tools are essentially limited to an electric
drill with bits, a few hand screwdrivers, and an exacto knife.  I
sometimes get access to a hacksaw, at which points I do all my cutting.
If I need anything other than that, I have to order it.

Chris B

On Tue, 2007-10-09 at 12:44 -0600, S&JY wrote:
> 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
> 
> 
> 
>