Re: Help! My Coil Blew Up

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

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