[Prev][Next][Index][Thread]
Re: coil design
Subject: Re: coil design
Date: Sat, 17 May 1997 17:55:36 -0400 (EDT)
From: FutureT-at-aol-dot-com
To: tesla-at-pupman-dot-com
<< Capacitors in series, or parallel to the high voltage
> source? My last effort was with the capacitor in parallel
> to the neon transformer - in fact I didn't rea;ise that
> the capacitor could be in series.
Joe,
Glad you're ready for coiling. I recommend placing the spark cap
directly
across the transformer output (cap in series). There's been many
discussions
on this list regarding the best cap placement, but most consider this
design
most reliable.
> Alternating or direct HT source? My admittedly weak grasp
> of theory suggests DC should be better, because some of
> the charge on a capacitor would be neutralised at each
> cycle of an AC current.
The capacitor will fully charge and then discharge through the gap, one
or
more times during each AC half cycle. Thus, in a way, the input AC
"looks"
like DC to the tank circuit. An AC system is much simpler and more
reliable,
and probably will give better performance unless the DC is very
carefully
designed and built. With DC, there are losses in the diodes, in the
filter
caps, in the large chokes that are required, in the protective bypass
caps
that are needed, etc. In fact, I doubt that any DC system can
outperform an
AC system because of these losses. A DC Tesla coil is also much more
dangerous because of the stored energy in the filter caps which may lead
to
shock and/or explosion. I have built both pulsed and steady running DC
Tesla coils with sparks up to 62" long, and input powers up to 6kVA, at
18kV.
It's a good idea to use safety gaps on the transformer and perhaps
"safety"
resistors in series with the transformer HV outputs. Enjoy your
coiling and
be safe,
John Freau
> I would be grateful for some empirical data.
> Have fun
Joe Cummings
>>