RE: Terry's DRSSTC - Frequency/Pulse Width Controller

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: Terry Fritz <teslalist@xxxxxxxxxxxxxxxxxxxxxxx>

Hi,

Well after thinking about it a lot, I decided to just us a Basic Stamp 
Microcontroller.  It can be programmed to do all kinds of neat tricks which 
might be very interesting. The pulse width and timing can be varied from 
cycle to cycle in almost any way one chooses.  The timing is also very 
accurate. I also had about 90% of the parts just laying around ;-)

The schematic is at:

http://drsstc.com/Design/PulseContoller.gif

The program can be easily changed through the serial port as 
needed.  Center off rocker switches allow the pulse width and BPS rate to 
be moved up and down.  On off switches and two LEDs provide indication of 
what it's doing.  A transistor buffers the current to the LED fiber optic 
transmitter.  A simple 9 volt battery runs it directly since the controller 
has it's own regulators and all.

The 1st shot at the program is at (it is just a text file that can be 
opened with any text program):

http://drsstc.com/Construction/DRSSTC-100.bsp

It already does a few cute tricks like resetting the pulse width to zero 
when it is turned off and enforcing limits on the range of the pulse width 
and BPS rates.  I think this is the way to go for really messing with a 
coil!  You could like flash the streamers in and out.  Or, briefly blast 
the streamer with a long pulse width and high BPS rate after a second or 
two to really push power into the streamer without really overloading 
anything.  It can also do very reproducible sparks when one want's to 
ponder things and study them. It would be able to run the streamers right 
to the edge of overheating the IGBTs or tripping the breaker since it is so 
well controlled.  One could even blast it at full power and then program a 
rest before tying again.  Of course, the "linear" control thing is now trivial.

With the fiber optic link, there is little danger of hurting the controller 
and it will be in a heavy armored box and all.

So I think it will be a cool way to go.  Many thanks for everyone's 
suggestions.  I though long and hard on them.

Cheers,

	Terry