OL-DRSSTC 7

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: Terry Fritz <vardin@xxxxxxxxxxxxxxxxxxxxxxx>

Hi,

Not anything "dramatic" to report since I am mostly just "fiddling" 
with it ;-)  Here is the mess as it now stands ;-)

http://hot-streamer.com/temp/OL-DRSSTC-05-06-001.jpg

I am just charging it up with a low current DC supply at the 
moment.  I had to take the trigger capacitor down to 200nF to get the 
trigger pulse inside 4uS pulse width.  The wire loop through the CTs 
slowed it way down, so the 1uF cap had to go away.  Have to keep the 
loop as short as possible too.  Rise time is about 1uS.  The 1.5 K 
resistor is at 150C now* and starting to turn a little brown.  Glad I 
buy the best ones that can take some abuse :D  that will take some 
re-engineering latter...  But the SIDAC trigger circuit is flawless...

Trying to tune up the pulse trigger circuit:

http://hot-streamer.com/temp/OL-DRSSTC-05-06-002.gif

The gate voltage from the trigger is in blue and the primary current, 
into mostly a resistor, is in yellow.  The primary current is "taking 
over" the pulse trigger well.  the coil's current seems to be out of 
phase...  The gate parallel resistance is 100 ohms.  That seems to be 
about right to damp the Lct vs. gate capacitance "ring" which is 
about 20kHz as predicted.

When let loose, you can see the coil ringing "way out" in the 
background right now:

http://hot-streamer.com/temp/OL-DRSSTC-05-06-003.gif

Fo is too high (I took out the protectors, which I need to put back 
in...) and the thing seems 180 out of phase...  LOTs of "phase" 
issues with all the CTs and current monitors and scope probe 
inversions...  I got all confused %:-))  So I stopped there...

*BTW - A cool toy is one of these infrared non-contact thermometers!

http://hot-streamer.com/temp/OL-DRSSTC-05-06-004.jpg

Many versions, but mine is just from Sears...  About $40...  But you 
can test temperatures of hot and high voltage stuff from a distance 
and they really DO work super well!!  Has a laser pointer, but you 
will have to just eyeball it at really close range...

Stay tuned...

Cheers,

	Terry