Re: "Astro-Coil P1"

Quoting coco-at-astroman-dot-com:

> I also picked up the following capacitors:
> 2mfd 10kv  (two of these)
> 1.6mfd 36Kv (one of these)

Quoting R. Hull:

 > Most of these PF correction caps are either paper or           
 > paper/plastic dielectric and can be used for pulse work,       
 > though not ideal for the purpose.  The caps you have are far   
 > too high a value for anykind of Tesla work, as is.  RHull

Back to coco-at-astroman-dot-com:

> With those caps. I mentioned... (the 2mfd. 10kv), you mentioned
> that modification would be ness. for any Tesla Coil usage. 
> would this modification be more than just series-ing enough of
> these to get the value down to a reasonable level (and thus 
> increasing the voltage rating), or is there design differances
> with these caps. that require modification (thus not really 
> being worth it for that type of usage) (Granted..it > would 
> take quite a few of these)

The cans have to be opened and the contents examined. HV
capacitors are generally built from several sub-units that are
wired together in the can. To obtain a very high value (i.e. the
2 MFD) many sub-units are wired in parallel to build up the

For Tesla coils a .2 MFD cap is getting pretty hefty and a 2 MFD
is not at all practical; also the voltage rating must be higher
than 10KVAC in order for the cap to survive in most coil systems. 

The solution is to rewire the sub-units in series rather than
parallel in order to reduce the value and increase the voltage
rating. The dielectric losses in many PFC caps (Power Factor
Correction caps) become large when the caps are used in Tesla
service, so unless the dielectric is all plastic expect to keep
your run times short.

Richard Quick

... If all else fails... Throw another megavolt across it!
___ Blue Wave/QWK v2.12