Re: Cap size for pig?

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: Mark Broker <mbroker-at-thegeekgroup-dot-org> 

On Fri, 19 Mar 2004 10:19:47 -0700, Tesla list <tesla-at-pupman-dot-com> wrote:

>Original poster: "Gerry Reynolds" <gerryreynolds-at-earthlink-dot-net> Hi Mark,
>
>I've been doing a lot of spice simulations for static gaps using all sorts
>of transformers, from plate transformers, to 12/30, 12/60, 15/30, 15/60.
>15/120, and PDT's (ballested).  I believe I have found a unifying equation
>for all these trannies that have resonable efficiency.
>
>Even the PDT follows the same curve when the effect the ballast has on
>current limiting is simulated.  The same equations used for NST's to
>calculate Cres can be applied to a PDT.

The ballasting is the reason for my statement regarding the high 
variability of PTs and pole mount transformers.  NST voltages and currents 
are pretty much standardized, so a simple table is easy to create for them.

BTW, I will endeavor to add "common" NST values to the chart that are not 
already listed if people send me the rating and mains frequency.


>PF = 0.78  -  0.27 * Cp/Cres   (PF flattens out at 0.6 and of course does
>not actually go negative)
>
>If the equation gives a PF larger than 0.6, use 0.6 instead.
>If the equation gives a PF smaller than zero, use zero instead

PF = Power Factor?

Interesting study!  Thanks for the info!

Mark Broker
Chief Engineer, The Geek Group