Re: Racing sparks study, was A couple cruddy coil pics

["boris petkovic" <petkovic7-at-xxxxxxxxx> (by way of Terry Fritz <twftesla-at-xxxxxxxxxx>)]

snip>
 I
> have found when out of tune and trying to put in
> some power, there is a
> potential where the racing sparks would travel down
> the secondary the entire
> length "starting" at the top and traveling to the
> bottom.
-----
In my opinion ,this is likely to happen when primary
rings at considerably higher frequency than 1/4
resonant frequency of secondary.Not just that 3/4
resonant frequency causes significant local voltage
gradients over secondary structure, but certain
frequency somewhere between 1/4 and 3/4 Fo could
create even more danger situation where point of high
V gradients travel in space and time along secondary,
and when meet place suffering weak isolaion, cause
damage.  

On the other hand ,for primary significantly lower
frequencies than 1/4 secondary one ,which is also out
of tune condition,voltage gradients are smaller than
in typical 1/4 mode of run.
This situation doesn't present danger. 
----



> Racing Sparks overcoupled = bottom to top direction?
> 
> Racing Sparks out-of-tune = top to bottom direction?
> 
> 
> Is this true for other coils out there or just
> coincidence? 
> 
----
On my old secondary I had not seen any varning in form
of racing sparks before flashover occured over
structure.I kept coupling constant but increasing bang
size was too much for that secondary to be taken.   

Regards,
Boris

__________________________________________________
Do You Yahoo!?
Yahoo! Shopping - Thousands of Stores. Millions of Products.
http://shopping.yahoo-dot-com/