Original poster: "MIKE HARDY" <MHARDY@xxxxxxxxxx>
DC, you say the 36" diameter toroid is sufficient for an 18" sec. However
you say 3 to 4 times sec diameter is ideal. And you further state that the
toroid on the M-200 was 48", thats nearly 2 1/2 times the sec diameter of
20". This is proportionally larger than mine. Why don't you think I'll have
secondary strikes?
----- Original Message -----
From: "Tesla list" <tesla@xxxxxxxxxx>
To: <tesla@xxxxxxxxxx>
Sent: Wednesday, February 08, 2006 7:17 PM
Subject: Re: Toroid size on Big Coils
> Original poster: "D.C. Cox" <resonance@xxxxxxxxxx>
>
>
> Mike:
>
> If you use a 36 inch dia. toroid on a coil similar to my M-150
> design, which has 18 inch dia. sec coil, there will not be any toroid
> to coil strikes.
>
> I didn't have in stock a large enough toroid for the M-200 design
> that you saw get damaged. We normally use a 60 inch x 20 inch toroid
> size on this coil and during the Cheesehead event we only used a 48 x
> 12 inch toroid which didn't offer enough electrostatic shielding for
> the sec coil.
>
> Good rule of thumb is to use 3-4 x dia. of sec coil for major toroid
> dia. and then you will not have any problems. A 3:1 major to minor
> toroid dia. also gives the correct ratio for this toroid design ---
> either spun or mesh toroid --- makes no difference to the sparks.
>
> Email off-list and I can share a unique design for a chicken wire
> toroid like we had on the Big Bruiser that can be constructed for
> under $125 in sizes up to 6 ft. in dia. Big Bruiser uses a 10 ft dia
> x 24 inch cross section for it's toroid.
>
> Dr. Resonance
>
>
> Subject: Toroid size on Big Coils
>
>
> >Original poster: "MIKE HARDY" <MHARDY@xxxxxxxxxx>
> >
> > From what I see on the profesional coiling sites, in particular KVA
> > effects, and Tesla Technology Research, the toroids seem small for
> > the size of the larger coils. I know the cost of large spun toroids
> > is prohibatively expensive. In the case of the M-13 magnifier, the
> > majority of pics, show the discharges comming off the corona ring
> > and not the toroid. With this coil, and Electrum, many of the arcs
> > seem to be hitting the secondary. At the Cheesehead teslathon this
> > past summer, the M-200 of D.C. Cox had several secondary strikes,
> > one of which severely damaged the sec. He said 'that's what happens
> > with too small of a toroid. How does one avoid this kind of
> > catastrophic damage? I'm planning to make a coil similar to DC's
> > M-150. It uses an 18" form, and I have a 36" spun toroid. I don't
> > want to destroy my secondary.
> >
> >
>
>