Re: Cap size

To: tesla-at-pupman-dot-com
Subject: Re: Cap size
From: Gary Lau 22-May-1999 1149 <lau-at-hdecad.ENET.dec-dot-com> (by way of Terry Fritz <twftesla-at-uswest-dot-net>)
Date: Sat, 22 May 1999 19:15:11 -0600
Approved: twftesla-at-uswest-dot-net
Delivered-To: fixup-tesla-at-pupman-dot-com-at-fixme

>Original Poster: FutureT-at-aol-dot-com 

>>Just one point can you tell me how a matched cap and power supply
>>IE reso charging mode puts added stress on the power supply.
>> Cheers Mike Tucknott

>Mike,
>
>When using an NST, with a reso-cap, the NST output voltage may go
>higher than normal, and stress the NST insulation.   Using a pig supply,
>reso, or non-reso would not be determined by the nature of the pig, but
>rather by the adjustment of the inductive ballast.  I don't know if pigs
>are usually run in reso-mode (ballast-wise), probably not.  I suspect
>they run smoother in non-reso mode.  Pigs can take a lot of abuse,
>but it would be desireable to adjust the ballast for smoothest results,
>and a good power factor, etc.  I.e. just adjust the ballast for best
>results regardless of the cap sized used.
>
>John Freau  

Since resonant charging is generally used with static gap systems, I
assume that's what we're talking about.  In such systems, the voltage seen
by the cap or NST should not be any higher in a system using resonant
charging.  The peak voltage is strictly governed by the gap setting.
At one point, the consensus was that by using resonant charging, more
power could be extracted from the NST by means of causing the cap to
charge faster and result in a higher BPS.  A higher BPS would stress the
cap more, but the voltages would be the same.  Recent simulations and
discussions now suggest that there's nothing special, performance-wise,
about using resonant charging.

Gary Lau
Waltham, MA USA