RE: Capacitor Size

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: "Lau, Gary" <Gary.Lau@xxxxxx>

The mains-resonant cap value for a 15/30 NST with 60 Hz power is
.0053uF.  It was once thought that this would hit a performance
sweet-spot, but I don't think this is so.  Non-linear behavior
(ferroresonance) of the NST core makes the mains-resonant cap value a
moving target.

The rage these days is to use a Larger Than (mains) Resonant cap value.
The calculated mains-resonant value multiplied by the square root of 2
(or was it 3?) is often cited as the optimum value.  Personally, I've
found that 2X the mains-resonant value works well.  I doubt there's any
kind of sharp sweet spot, so any of these factors will all work.

One thing that is clear is that streamer length is proportional to bang
size.  So if your static gap fixes the bang voltage, you can get a
bigger bang and longer streamers at a reduced bang interval by using a
bigger cap.  But if your wife favors your existing cap, you might get a
bigger ba...  OK, I'll stop there.  Always a compromise...

Regards, Gary Lau
MA, USA



> Original poster: "Dirk Stubbs" <dirk@xxxxxxxxxxxxxx>
>
> I have a question about sizing of a capacitor. My power supply is a
> NST 15kV at 30mA. I originally planned on using 10 doorknob
> capacitors which are rated at 30kV with 0.006 uF total(each was 620
> pF). However I have a question about the needed capacitance for my
> TC. Most of the references such as websites  and calculators said
> that I need .0053 but I see people saying you need .008-.009 uF.
>
> What size is correct?
>
>
> What will happen if I use my current capacitor setup?
>
>
>
> I would like to use my current setup to save money. The wife has
> about had it with the TC as it is . J
>
>
>
>
> Thanks,
> Dirk
>
> -
>