Improvement to audio modulated SSTCs?

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

Original poster: Mr Gregory Peters <s371034-at-student.uq.edu.au> 


NOTE TO TERRY: not sure if you got this post to the list, and blocked it or 
not, but I sent it a day or two back. Please let me know if these "thinking 
out loud" emails are bothering you. - Greg

Hello all,

I have never witnessed any kind of SSTC in operation (there just aren't 
that many coilers in Australia, and most of them are 000s of kms away), but 
I have been looking at some schematics for audio modulated SSTCs. Many 
pages out there claim that the output has a distinct hiss or buzz, in 
addition to the music.

Is it possible that this may be due to ripple in the HV supply? In regular 
audio amps (a tangent I took for the last year or two, while taking a break 
from TCs) a supply ripple of only a few mV can cause substantial hum at the 
speaker, particularly when dealing with the single-ended class a amps I was 
fiddling with. I have never heard a SSTC, so I can't say if the hiss is the 
result of a 50/60/100/120 Hz ripple, or purely the nature of a spark 
discharge, but one would assume that because the TC "amplifies" the input 
voltage, any ripple in the input voltage would cause ripple in the output.

Anyway, back on topic, has anyone tried properly regulating the HV supply 
on the AMSSTC? This can be done easily with a N channel mosfet follower 
"biased" by zener diodes, with significant current ability:

http://www.passdiy-dot-com/images/projects/zv3-f2.jpg

paralleling devices in this configuration is easy for more current if you want.

See the full article at http://www.passdiy-dot-com

Just thought this might interest you all. I might be barking up the wrong 
tree, but a properly regulated supply is the only way for true 100% cw 
operation right?

Sorry for all these "thinking out loud" posts lately, but it is clear that 
with the new developments of DRSSTCs, OLTCs, etc,  SSTCs are going to 
become real contenders in the coiling arena, so info like this won't go 
astray. Also the availability of "production" SSTC boards (thanks Dan) has 
encouraged more people to construct these than ever.

BTW, this "thinking out load" is going to pay off.......Just wait till you 
guys see the SS based coil I am already constructing :) It's going to 
really be pushing the envelope in SSTC design..........No new ideas really, 
just the old ones taken to the extreme.

Cheers,


Greg Peters
Department of Earth Sciences,
University of Queensland, Australia
Phone: 0402 841 677
http://www.geocities-dot-com/gregjpeters