Re: secondary question

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

Original poster: Bert Hickman <bert.hickman-at-aquila-dot-net> 

Tesla list wrote:

>Original poster: "Steve Conner" <steve.conner-at-optosci-dot-com>
>  >Long streamers are the
>  >result of repetitive growth along a hot and possibly partially
>  >ionized channel of air.
>OK, then why doesn't that hot and partialy ionized channel of air form down
>the middle of the secondary? :)
>Steve C.
>
>.

Steve,

Field Control.

The area along the outer horizontal edge of the toroid is the region of 
highest E-field stress, so it becomes the point of initial breakout. The 
region inside the secondary has a vertical E-field that's (approximately) 
linear with height - corona does not easily form in a uniform E-field. If 
you can prevent the corona, you can inhibit the early stages of streamer 
development, and you'll prevent streamers from forming.

Beginners sometimes mistakenly drill a small hole in the coil form to run 
the secondary wire up to the toroid. The stronger E-field near the small 
wire now becomes a source of corona and streamers. Once started, the 
initial corona is rapidly followed by streamers and arcing.

If you can assure that initial breakout always occur FIRST only in 
desirable areas, protected regions (such as the region inside the secondary 
or other areas with significantly higher breakdown voltage) will NOT break 
down.

Best regards,

-- Bert --
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