Re: Cap values for 12/120(s)


	Typically, you just use the old V/I=R formula to find the source impedance
of the transformers.  Then you use R=1/(2 x pi x 60 x C) to match the
capacitor to that source impedance.

So, for say three 12000 volt 120mA transformers:

12000 / (3 x 0.120) = 33333 ohms

1/ (R x 2 x 60 x pi) = C

1/ (33333 x 2 x60 x pi) = 79.5nF 

If you have 50 Hz AC line frequency replace the 60s with 50s....

Your friend is probably pretty close.



At 02:51 PM 6/24/99 -0400, you wrote:
>Hi all , Here's the situation I have a few 12/120(s) and need to figure out  
>what size cap(s)  I need to reach resonance ? When trying to figure this out 
>my friend Dave said it could need as much as a.06!  This seems like a bit 
>much to me , however when we paralleled two together  on our 8" coil with my 
>.027 plate cap it worked very well.
>These are 40year old Solas (very robust) 800va transformers.With the primary 
>open resistance end to end is1950 ohms and inductance measured on one side is 
>85h and 80h on the other with 116h end to end.
>If anyone can help figure this out  it would  be greatly appreciated.We plan 
>on running one or more so I need to know  idividual  cap size as well as for 
>running 2,3,or4 trannys he hehe! 
>All in prparation for the So Cal  Teslathon  Thanks again Mike Church