Re: DC Resonance Charging Advice Sought

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

Original poster: "Bert Hickman by way of Terry Fritz <teslalist-at-qwest-dot-net>" <bert.hickman-at-aquila-dot-net>

Tesla list wrote:

>Original poster: "Dave Kyle by way of Terry Fritz <teslalist-at-qwest-dot-net>" 
><dave-at-kyleusa-dot-com>
>Thank you for your responses! Please see my comments in line
<SNIP>
>This leads to the question, on which side of the inductor the de-Qing diode
>should be placed? Based on Richie's information and Steve's design I put it
>on the power supply side but I have seen other references with the de-Qing
>diode on the tank side. Any thoughts?

I suspect it doesn't really matter very much. The sudden voltage drop when 
the gap fires can cause significant voltage stress across the outermost 
winding layers of the charging reactor. And, placing the de-Qing diode 
between the reactor and the gap really doesn't change this situation.

Transformers and reactors that are specifically designed for HV testing or 
pulse work often use tapered windings to better "balance" the voltage 
stresses between winding layers to improve their robustness in the presence 
of high speed (spark breakdown) transients. Your DC reactor does not use 
these techniques and may be more vulnerable. I'd recommend adding a simple 
RC filter (such as the "Terry filter") between your charging supply and the 
spark gap to slow down high dv/dt transitions and prevent VHF parasitics 
from getting back into the charging reactor and diodes.

Best regards and keep us posted on your progress!

-- Bert --
-- 
-