Re: DC Resonance Charging Advice Sought

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

Original poster: "S & J Young by way of Terry Fritz <teslalist-at-qwest-dot-net>" <youngs-at-konnections-dot-net>

Dave,

I will comment on the need for PFCs.  I found they did not help at all with
my DC supply.  The reason I believe is because the filtering capacitance
gets reflected back as a much higher value across the primary, and so PFC is
already in place.

By the way, the 7 uF smoothing capacitor is highly dangerous and much more
than you need.  The smoothing cap need only be about ten times your tank
capacitance.
--Steve Y.
----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Monday, August 11, 2003 12:12 AM
Subject: DC Resonance Charging Advice Sought


 > Original poster: "Dave Kyle by way of Terry Fritz <teslalist-at-qwest-dot-net>"
<dave-at-kyleusa-dot-com>
 >
 > Several months ago after being inspired by Steve Conner's very impressive
DC
 > coil http://www.scopeboy-dot-com/tesla/index.html I started my own DC coil
 > project. I was drawn to the very elegant power control permitted by DC
 > resonance charging. Richie Burnett's site offers an excellent explanation
 > and provided the designs rules that I have followed
 > http://www.richieburnett.co.uk/dcreschg.html#resonant. Of course for the
 > ultimate expression of DC resonance charging one only needs to look at
Greg
 > Leyh's incredible Electrum http://www.lod-dot-org/index.html.
 >
 > I have now completed and tested to 8KVDC (without load) the DC power
supply
 > which can be seen here:
 > http://home.austin.rr-dot-com/dkyle/images/temp/dc_tesla_ps.jpg. For scale the
 > base disk is two feet across. You will note the very large black power
 > transformer, full wave rectifier and de-Qing circuit, smoothing capacitors
 > with safety bleeders and grey charging inductor.
 >
 > Specifications are as follows:
 > 4.700KVAC 775VA transformer (6.65KVDC rectified)
 > 7uf -at- 10KVDC of smoothing capacitors
 > 20Henry -at- 15KVDC inductor
 >
 > Under construction:
 > ..02uf -at- 20KVDC cap
 > 0 to 500bps RSG
 > 4 inch x 25 inch secondary with 1400 turns of #26 gauge wire
 > 6x24 inch toroid
 > 15 turn primary (tuned at 11 turns)
 >
 > Advice needed on the following:
 >
 > 1.) I have yet to resolve the system grounding. Is it advisable to ground
 > the center point of the main transformer for safety (like an NST)? Or
would
 > it be better to simply ground the negative side of the DC power supply? Or
 > let it all float and just ground the secondary?
 >
 > 2.) I am assuming this transformer is not shunted (current limited) but
 > short of dismantling it how can I tell? DC resonance charging is self
 > current limiting so that will not be an issue but I would like pull
current
 > slightly higher than the transformer's rating.
 >
 > 3.) Assuming the transformer is not shunted would there be any benefit to
 > adding PFC caps?
 >
 > 4.) I have noticed in some of the very few DC coils documented on the net
 > that a clamp diode and air inductor are sometimes added to the charging
 > circuit presumably to protect the supply and caps from over voltage and
 > transients. Can anyone comment on the need for this?
 >
 > Dave
 >
 > =========================================
 > Dave Kyle
 > Austin, TX USA
 > Email: dave-at-kyleusa-dot-com
 >
 >
 >