Re: "Green Monster" magnifier

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

Original poster: Edward Wingate <ewing7-at-rochester.rr-dot-com> 

Tesla list wrote:
 >
 > Original poster: "J. B. Weazle McCreath" <weazle-at-hurontel.on.ca>
 >
 > Hi Dan, Coilers,
 >
 > You've done a nice job on your primary/secondary for the "Green Monster"
 > magnifier you're building!  I too am working on one, and just last week
 > I completed the primary which is 50 feet of 1/4 inch copper tubing that
 > is wound helically on an 11 inch diameter chunk of plastic water main.
 >
 > The question I have for you and the list members has to do with how much
 > insulation is required between the primary and secondary?  The plastic
 > water main section has a 5/8 inch thick wall, which I'm hoping is more
 > than adequate.  The secondary will be wound on a similar piece of pipe
 > that is 9 inches in outside diameter.  That leaves a wee bit of room
 > to cover the windings with some poly sheeting if it's neccessary.
 >
 > Here's the specs so far:
 >
 > Primary  -  11 in. dia. by 9 in. long helix with 17 turns total.
 >              Measured inductance is 64 uH.
 >
 > Secondary - 9 in. dia. by 20 in. long of #12 for 230 turns.
 >              Calculated inductance (WinTesla) is 4.4 mH.
 >
 > Sorry that I have no pictures, but Santa didn't get me the digital
 > camera that I'd been hoping for.
 >
 > 73, Weazle, VE3EAR/VE3WZL
 >
 > Details of my "Hyperbaric Gap" and Tesla coil are at:
 > http://www.hurontel.on.ca/~weazle

Weazle,

You should be fine with the 5/8" and may not need any extra insulation.
It depends how high you want to go with the K factor. Anything much over
.5 becomes difficult to insulate. The K factor on my system is .482 and
I have approximately 1/2" of polypropylene between the primary and
secondary/driver with no hint of arcover, my driver is 32" in diameter.

Your 4.4 mh of inductance is good. The lower the better on the driver
coil.

Ed Wingate RATCB