10KV RMS -at- 300MA
From: Skip Greiner[SMTP:sgreiner-at-wwnet-dot-com]
Sent: Thursday, June 19, 1997 6:00 PM
To: tesla list
Subject: 10KV RMS -at- 300MA
Hi Malcolm, Barry and All
I think I have finally stumbled on the problem besetting my coil....
As you know the H&R transformers use a capacitor and a resonant winding
to achieve the 5kv output voltage for which they are rated. In my case I
do not use the resonant winding or the supplied resonating capacitor. I
use the primary cap to resonate the transformer. I chose the .081uf
value because this particular value allows the tranny to put out 5kv or
maybe a little more. At around 100v input the safety gaps break down and
they are set to 5kv.
I believe that by attempting to run at higher break rates the resonant
charging is somehow screwed up. So far I have not figured out a way to
look at the transformer output, but I would bet it is strange when the
break interferes with the resonating.
To answer a couple of the other questions:
1. I do not use any kind of ballast. These trannies are current limited
2. The output voltage does not sag...at least the reading on the
rectifier meter that I use to monitor it does not change. The gap always
breaks down at 10kv when I run the input voltage up.
3. I am using the tightest coupling I can. Any more and I get racing
4. Higher cap values increase the input current (to over 30A) but have
little influence on spark length. Lower cap values (lower than .08uf)
make the input current lower and the tranny output voltage goes lower
and the spark length decreases. I have tried various k factors and
various numbers of turns in the primary. I have also varied the top
loads over a fairly large range. My original .081uf primary cap seems to
be best for maximum spark at lowest input currents.
Still perplexed in Detroit, USA