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Re: New solid state pictures




Hi David, all,

> Original Poster: "David Trimmell" <davidt-at-pond-dot-net> 
> 
> Hi Richie, all,
> 
> Last Summer I experienced a example of the secondary coil heating, as you
> describe, that actually caused it to "burn" up! Yes, smoke and small
> flames! This was while running with grid audio modulation (filtered DC -at-
> around 2kW), and extended running, perhaps 15-20 min. I attributed the
> heating due to inductive heating, what do you think?

I used very thin wire for the SSTC pictured on my web page to keep the
overall TC very compact,  but I'm sure the current is far too high near 
the bottom of the resonator.  The resonator pictured on the web page
actually got too hot to touch after a 2 minute CW run. Some turns near the
bottom shorted and actually burned complete rings in the varnish !

I must try the audio modulation trick also.

The point about smoke and flames is very valid.  I was amazed at the
severity of fires which develop instantly if there was a flashover.  I
tightened the coupling too far,  and there was a flashover.  I cut the
power as soon as I saw the ball of flame between the primary and
secondary,  but the secondary was burned beyond repair !

I'm actually glad that happened,  because it was a graphic demonstration
of what would happen if someone accidentally got a limb too close :-(

> See my photos running  with half-wave pulsed DC at
> http://www.pond-dot-net/~davidt/webdoc2.htg/Photos.htm
> 
> Regards,
> David Trimmell

Very impressive, I particularly like that spidery effect.  Do you know why
the sparks are totally free of any branching ???

Does a VTTC coil track the drop in resonant frequency as there is breakout
from the resonator ???   Maybe this causes the long straight sparks ???

							Cheers,

							-Richie,