RE: [TCML] My first tesla coil

["Lau, Gary" <Gary.Lau@xxxxxx>]

Hi Brian,

Nice construction, and not bad for first light.  Here's my take on areas for improvement.

Your cap value appears to be targeting the mains-resonant value (the value that would resonate with the NST secondary winding at 60Hz).  This used to be thought to be the best value, but current thinking and experience shows that using between 1.5-2.0X this value (LTR or Larger Than Resonant) is better, both from a performance and from a "which is better for my NST's life" perspective.  So for your 9/30 NST @60 Hz, I would target .013-.018 uF.  Paring down your MMC array to seven of the .1uF/3kV caps would give you .014uF @21kV, still plenty of margin.

Your topload also looks small by current standards.  Unfortunately there is no formula for calculating what the size should be, but it is the experience of myself and most others that bigger is almost always better.  A terribly crude rule of thumb might be to have the major diameter be comparable to the secondary length, but this does not take into account the power or bang size of the coil, which is probably the more pertinent determining factor.

Of course if you switch to a bigger top load you'd also need to retune your primary.  But if you increase your cap size, things may just work out!

I also notice that your gap has no forced air.  Most find that having forced air flow through the gap improves performance.

Regards, Gary Lau
MA. USA



> -----Original Message-----
> From: tesla-bounces@xxxxxxxxxx [mailto:tesla-bounces@xxxxxxxxxx] On
> Behalf Of Brian
> Sent: Sunday, August 30, 2009 10:46 PM
> To: Tesla Coil Mailing List
> Subject: Re: [TCML] My first tesla coil
> 
> Hi, nice work on the gun! a work of art.....first, nice work on the first
> coil.....i would take a piece of plastic, and see if i could gently nudge
> the spacing on the primary to get it more even all the way around...good
> even spacing on the primary helps.....then tuning, changing, tuning,
> changing toroid, tuning.....eventually you will find it will get better as
> time goes on....
> good luck, brian f.
> ----- Original Message -----
> From: "Peter Baitz" <ussenterprisencc1701@xxxxxxxxxxxxxx>
> To: <tesla@xxxxxxxxxx>
> Sent: Sunday, August 30, 2009 8:00 PM
> Subject: [TCML] My first tesla coil
> 
> 
> > Hello,
> >
> > I am new to tesla coiling and this website
> >
> > http://www.freewebtown.com/baitzobservatory/tesla/index.html
> >
> > is my brief documentation and picture review of my first tesla coil.
> >
> > Made extensive use of DeepFriedNeon.com for constructing the details, and
> > other websited for ideas, tips and information and safety.
> >
> > My only question I have is a 9000 V 30mA coil is supposed to put out 23"
> > sparks/streamers, but I am getting maybe half that at most. Tuning the
> > primary coil to 6 or 8 turns stops any streamers, and anywhere in the 7th
> > ring, especially 7 on the mark, seems to be it's max. - you can even hear
> > it in the way the spark gap purrs more evenly and loudly.
> >
> > Links to videos are also on the sight. Feedback much welcome as this is my
> > first coil.
> >
> > Thanks to the coil community for all the input.
> >
> > BTW I also make some props as a hobby, and while I was doing the coil, I
> > also built the Warehouse 13 Tesla unit:
> >
> >
> http://i230.photobucket.com/albums/ee64/ncc1701_photos/warehouse13/My_Hom
> emade_Teslagun_04.jpg
> >
> > Peter
> >
> >
> >
> >
> > _______________________________________________
> > Tesla mailing list
> > Tesla@xxxxxxxxxxxxxx
> > http://www.pupman.com/mailman/listinfo/tesla
> >
> 
> _______________________________________________
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