[Prev][Next][Index][Thread]

Re: First Light

In a message dated 9/28/98 4:59:58 PM Pacific Daylight Time, tesla-at-pupman-dot-com
writes:

<< Original Poster: "Basura, Brian" <brian.basura-at-unistudios-dot-com> 
 
 Tesla List Members,
 
 I fired up my 6.5" coil for the first time this weekend.  
 
 Started with tiny 6" sparks to a ground rod. I then tuned, reduced the
 number of gaps, lowering the secondary, increased the size of the capacitor
 safety gap, and tuned some more.  I was able to achieve a consistent 32"
 breakout into the air and a couple of weak 35" strikes to the grounded rod.
 This was at approximately 960 watts and utilizing a .014mfd capacitor.
 
 I then upped my capacitance to .022mfd and re-tuned. The sparks were white
 hot and loud.  The distance is a consistent 36" to a grounded target. The
 sparks are hot and without a target tend to go upward at a 45 degree angle.
 Raising the toroid an additional inch didn't seem to effect the performance
 of the sparks but it did change their direction.  The sparks now go straight
 out (horizontal) from the toroid.
 
 I then varied the configuration of my current limiter for my PT. I started
 with a MOT (shorted secondary) and series resistance.  I found the best
 performance using a MOT measuring 11.7mH in parallel with 14.2 ohms.  There
 was no HV current change as measured into a resistive load (80ma) but in
 operation the color and sound of the sparks did intensify.
 
 I am having a strange problem I can't identify.  As I ramp up the input
 voltage the RQ style SG starts to fire (very consistent) and then strong
 streamers break out.  After 9-10 seconds of operation the streamers loose
 intensity and the SG starts to fire in intermittent bursts (1-2 seconds then
 a 1-2 second pause). I've messed with air flow and more seems to make the
 problem worse but reducing the airflow also makes it worse.  I did find an
 undersized wire in my tank circuit (those gremlins must have switched wires
 on me).  I'll fix that before my next run and see if that helps.  Any other
 ideas would be welcome?
 
 Before I shut it down last night I increased my input power to 1800W and
 made one last run. A white hot 5' streamer came straight at me, curved up
 and hit the garage door opener. WOW!!!  Then the safety gaps on my caps and
 PT started to fire at which point I immediately shut down.  Obviously I need
 to move outside, add my other capacitors (total .044mfd), and do more
 tuning.
 
 Construction pictures are at:
 http://www.hughes-ec-dot-com/~brianb/teslahome.html 
 
 I'll try and get some operating pictures up on the WEB next week.
 
 Thanks to everyone who posts on these lists.  I've learned a tremendous
 amount.
 
 Regards,
 Brian Basur >>

Brian,

Good job.  Congratulations.  Sounds like a good system.  If you are using a
potential transformer, I do not think a static gap will provide adequate
quenching.  You might need to build a rotary gap to get the best performance.
Also, increasing the primary capacitance as you have planned will help.  How
large is your toroid?  For comparison purposes, on my 6" diameter coil, I use
a 5kva transformer running at about 7.5 kva, a .05 mfd cap and two large
toroids, one 33" in diameter and one 40" in diameter.  I would bet your coil
is capable of 100" to 120" sparks!  I am glad to hear you have a safety gap
across your caps.  Not doing this initially cost me two commercial (expensive)
caps.

Ed Sonderman