Re: First Light for 10" Coil.

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

Original poster: Ben Haylett <bhaylett-at-shaw.ca> 

Congratulations on an impressive looking coil, Peter.

How do you (and presumably Ted as well) have your 6 MOTs configured? In
other words, what sort of series/parallel arrangement are you using, and
what would the output voltage be?

Ben

----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Tuesday, December 23, 2003 10:46 PM
Subject: Re: First Light for 10" Coil.


 > Original poster: tesla <tesla-at-paradise-dot-net.nz>
 >
 > Greetings Peter
 >
 > A most interesting coil and quite similar to my own
 >
 > Very interested in the way you have done things
 >
 > The differences
 > Mine has 90nF of the 1600v 0.33uF caps (like Robin Copini)
 > SRSG is currently 300bps and all electrodes are near the 90deg and 270deg
 > points. This needs fixing, How did you decide on the location for your
 > rotating electrodes to set timing
 >
 > I use PFC of over 100uF and up to 6 MOT's. The MOTs I have are in oil and
 > phased about ground. I use 900watt xfrmrs. I run fixed ballasting of
22mHy.
 > I was intrigued by your ballast and would be interested in the short form
 > specs on that.
 >
 > I have just purchased the bits to put a dedicated outlet at the house so
 > should be able to run the thing flat out.
 >
 > My operating freq, toroids and so forth are pretty similar, I can maker
the
 > beast do 2 metre O/P but I know it will do better when I get SRSG timing
 > better and a dedicated mains. It will run > than 40amps if I let it so
need
 > to keep it at that level or things start to go wrong, like fuses start to
 > blow.
 >
 > Hope to hear more from your expts
 >
 > Rgds
 > Ted L in NZ
 > ----- Original Message -----
 > From: "Tesla list" <tesla-at-pupman-dot-com>
 > To: <tesla-at-pupman-dot-com>
 > Sent: Wednesday, December 24, 2003 8:54 AM
 > Subject: First Light for 10" Coil.
 >
 >
 >  > Original poster: "Peter Reid" <peter-at-reidconsulting-dot-com.au>
 >  >
 >  > Hello Everyone on the Tesla Coil Mailing List.
 >  >
 >  > I have just finished building my new MOT powered 10" Coil and managed
to
 >  > tune it somewhat. I am quite happy with the results so far, however I
am
 >  > wondering if anybody could shed some light onto areas I should work on
In
 >  > order to improve the spark length and power handling capabilities of
this
 >  > coil. So far I have managed occasional 8.5ft Power Arcs to a grounded
rod.
 >  > However I feel that the coil is still capable of a lot more. Initially
the
 >  > spark output was quite poor until I increased the coupling between the
 >  > primary and secondary. (I don't think I've gone too far).
 >  >
 >  > I will list the specifications below. With the current setup I am
getting
 >  > quite powerful arcs to the strike rail and ground with-in about a 3ft
 >  > radius around the coil.
 >  >
 >  > I have posted some photos on my website for anyone that's interested. I
 >  > also have some pretty good video footage, but that isn't on the
 >  > webpage.
 >  > <http://tesla.reidconsulting-dot-com.au/>http://tesla.reidconsulting-dot-com.au
 >  > Any input / help with improving the current setup would be greatly
 >  > appreciated, I am just a little worried about burning up my secondary
if I
 >  > try and pump any more power though it.
 >  >
 >  >
 >  >
 >  > Coil Specs are as follows..
 >  >
 >  > Primary
 >  > Flat Spiral, Wound with ½ In Copper tubing, spaced but ½ inch.
 >  > ID = 12.7in
 >  > OD = 32.5in
 >  > Turns = 10.25, tapped at about turn 6.15
 >  > Primary sits 1.5ft above the ground on a specially made wooden
platform.
 >  > Strike Rail = 1/2copper tube raised by ½ inch around outside of
primary.
 >  >
 >  > Secondary
 >  > Wound on a 10" PVC pipe, which has been baked and sealed with many
coats
 > of
 >  > polyurethane.
 >  > Winding length = 41in
 >  > Wire Diameter = 0.9mm B&S Gauge 19
 >  > The bottom turn of the secondary is elevated 1 inch above the top of
the
 >  > primary winding.
 >  >
 >  > Toroid
 >  > 12" x 42.5" (Tube Diameter x Outside Diameter of Toroid)
 >  > Mounted 12in above the top winding on the secondary.
 >  >
 >  > Measured Res Frequency of Secondary is 84.8kHz, and primary has been
tuned
 >  > to exactly that. (Can someone please tell me if its worth trying to
detune
 >  > it by 1/3 of a turn to account for streamer loading etc?.)
 >  >
 >  > Capacitor
 >  >              0.15uF MMC Cap Bank made up of 144, 942C20P15K caps.
 >  >
 >  > Power Supply
 >  >              6 MOT Supply, Currently Ballasted to 40A -at- 240V (Using a
 >  > Sliding Choke Balast)
 >  >              Maximum line draw current of 80A -at- 220v when the ballast
is
 >  > removed. That's 17.6kVA J
 >  >              Approx 12kV output.
 >  >
 >  > Spark Gap.
 >  >              200bps Sync Gap, with a Remote Phase Adjuster.
 >  >              Single Gap, Tungsten static electrodes, and 4 x 8mm brass
 >  > threaded rod (moving electrodes) Spinning on a 12in
 >  > G-10 disc (3000 rpm) Gap spacing is about 1-2mm total.
 >  >
 >  >
 >  > BTW, Thanks to everybody who has contributed to the mailing list, the
help
 >  > I have received from you guys has been invaluable.
 >  >
 >  >
 >  > Regards
 >  >
 >  > Peter Reid.
 >  >
 >  >
 >  >
 >
 >