SSTC-Starting Out

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

Original poster: "Marry Krutsch by way of Terry Fritz <twftesla-at-qwest-dot-net>" <u236-at-earthlink-dot-net>

Hi All,

	I'm embarking upon a journey that will lead to the demise of many an
innocent semiconductor switch ;-)).  It's taken me 3 days to build one
of the three portions of the drive circuitry.  I wouldn't be surprised
if you guys could do it in 5 minutes, given my idiocy.

	Anyway, I finished the frequency controller.  It consists of a 555
timer, a dual J-K flip flop, various resistors, and 2 transistors.  For
my drive circuitry, I needed two square waves that were 180 deg out of
phase.  The flip flop does that nicely.  It also "squares up" the 555's
output.

	Next, I need to make the pulse width controller.  Do any of you have
schematics or ideas regarding single shot pulsers?  I need to generate a
pulse that is SHORTER than the incoming trigger pulse, that is variable
from 0.5 uS to 20 uS in width.  It can be either rising or falling edge
triggered.

	The final thing will be the duty cycle control (Stacato Circuit???),
but that should be easy.  I intend to feed the outputs from all three
controls to two 3-input AND gates (one for each set of two drive
transistors).  The output of each AND gate will drive the first stage of
the amplifier, which of course ends with the coil's main drive
transistors.  I'm not sure whether to use MOSFETs or IGBTs, but the
driver should work for either one at this point.

	The coil will run between 75-100 kHz if I use IGBTs, or 180-250 kHz if
MOSFETs are used.

	This thing has cost me a grand total of $5 so far.  The REAL money
flies away later ;-)).  I got 25 pounds of magnet wire for $40 at C&H
Sales last week, so the secondary is "in the bag".

	Feedback will be welcomed.  Pardon any spelling/grammar problems.  I
had to work late last night (2am), so my good half is still asleep ;-)).

Thanks,
Winston K.

BTW-Great work Terry!  I'm waiting anxiously for the post: OLTC-
:-))))))))))))