Re: Help! My Coil Blew Up

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

Original poster: "gtyler" <gtyler-at-drummond-dot-org.za> 

Use a pll with a phase shift network so that it runs with the voltage
and current are in phase. I have some circuits like this if you are
interested I could make a .jpg file from it for you.

George
----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Friday, February 06, 2004 3:04 AM
Subject: Re: Help! My Coil Blew Up


 > Original poster: Finn Hammer <f-h-at-c.dk>
 >
 >
 >
 > Tesla list wrote:
 > >Original poster: "Steve Conner" <steve.conner-at-optosci-dot-com>
 >
 > snip
 >
 > >I tend towards the "wrong frequency" explanation myself. The antenna
 > >feedback circuit isn't very "scientific", the phase shift (and hence
the
 > >oscillation frequency) is set by a bunch of things that aren't well
defined,
 > >like the capacitance of the antenna clamp diodes and so on. As an EE
it
 > >gives me hives just looking at it.
 > >When reading the above, bear in mind I've never built an ordinary
"inverter"
 > >type of SSTC, so it might be complete BS. If anyone out there is fond
of the
 > >antenna feedback circuit, flame away, but you won't change my mind :P
 > >Steve C.
 >
 > Steve,
 > I`m fond of the antenna feedback circuit, but I`m not going to flame
you
 > for pointing out that it is flawed.
 > It is still the best we`ve got right now.
 >
 > However, when I swich from 494 to comparator, it is obvious that the
 > antenna does not drive the coil at it`s res. freq.
 >
 > I know that my measuring tecnique is flawed, and doesn`t command awe
in
 > this forum, but still, I can push more power with the 494, and still
have
 > zero current swiching, whereas with the antenna/comparator, I get a
 > triangle like current.
 >
 > (Of course, I can adjust the 494 to produse a current square wave for
great
 > power throughput, but then it is hard swiching.)
 >
 > It appears to me, that it would be good to ad an adjustable phase
shift
 > option between the antenna and the comparator but I don`t know how to
do that.
 >
 > Any ideas, EE?  :-)
 >
 > Cheers, Finn Hammer
 >
 >
 >
 >
 >