Re: SSTC-Starting Out

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

Original poster: "robert heidlebaugh by way of Terry Fritz <twftesla-at-qwest-dot-net>" <rheidlebaugh-at-desertgate-dot-com>

Winston; on the output of your 555 put a simple RC differentiating circuit
followed with a 1N914 diode to select the + or - trigger you want. Connect
that to a one-shot MV to produce a gate out of whatever pulse width you
want.  
  Robert  H

> From: "Tesla list" <tesla-at-pupman-dot-com>
> Date: Sat, 24 Aug 2002 12:07:08 -0600
> To: tesla-at-pupman-dot-com
> Subject: SSTC-Starting Out
> Resent-From: tesla-at-pupman-dot-com
> Resent-Date: Sat, 24 Aug 2002 12:08:27 -0600
> 
> 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-
> :-))))))))))))
> 
> 
>