[TCML] capacitors

[bartb]

Hi Douglas,

douglas smith wrote:
> i was wondering 2 things
>   first, i have recenty run accross a 35 kv .03 uf pulse capacitor for 99.00
>   would it be better to use one like this or to use mmc combination ?
>   not sure but looks to me that it will cost about the same.please correct me if i'm wrong.
>   target cap .03uf
>   

If the pulse cap is rated for the pulse rate of the gap, then it may be 
fine. You might want to let the list know about any specs you can find 
out about. My opinion is both pulse and mmc's are equivalent if both are 
rated for the pulse rate (I use both). One thing about MMC's is if a cap 
fails, replacement costs is low. Not so with a pulse cap. For a .03uF 
cap size (nice and large), I personally would go after a pulse cap 
string (like three .01uF in parallel). But, $99 is hard to beat and a 
heck of a price if it's worthy of Tesla duty.

>   
>   secondly, as for spark length on javatc i get the same results with a nst 7.5/60 as i do
>   with a 15/30
>   please explain
>   
Spark length is based on John Freau's power equation which is 1.7 x 
sqrt(input power). Because the power for both transformers is 450W, the 
spark length comes out the same. Also, this spark length is based on 120 
bps and considered optimum. This is the spark length listed in the 
Transformer Power Section. There are two other spark length values (one 
in the static section and one in the rsg section). These spark length 
values are similar and based on power, but also includes bps, power 
across the gap, etc.. In some cases it's less than the JF equation and 
in some cases greater. I usually look at these personally. The main 
thing to remember is that all do not account for variations in gap 
efficiency. Those losses can be huge and directly affects actual spark 
length.

Take care,
Bart