Re: the cure for racing sparks

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

Original poster: "Steven Ward by way of Terry Fritz <twftesla-at-qwest-dot-net>" <srward16-at-hotmail-dot-com>




>From: "Tesla list" <tesla-at-pupman-dot-com>
>To: tesla-at-pupman-dot-com
>Subject: Re: the cure for racing sparks
>Date: Thu, 11 Jul 2002 18:38:21 -0600
>
>Original poster: "D.C. Cox by way of Terry Fritz <twftesla-at-qwest-dot-net>" 
><DR.RESONANCE-at-next-wave-dot-net>
>
>
>
>Any time you exceed "critical coupling" you begin the freq. splitting of 
>the
>main F (resonant) freq.  As soon as you have two separate frequencies you
>get oscillatory beats.
>
>I fly a twin engine Piper Aztec and the same exact effect occurs.  If you
>get one prop running just 10-25 rpms above the other there is a noticeable
>beating effect which is corrected with the prop governor controls (prop
>pitch).  The "beats" will drive the pilot nuts in a few minutes if not
>corrected.
>
>The same principle applies to Tesla circuits.  Exceed critical coupling and
>you have a HV peak at some other point than the top of the coil and "racing
>sparks" can occur.
>
>Coupling adjust, as you mentioned, is the cure.
>
>Many beginners have set up coils without enough primary inductance 
>available
>to tune properly and this also produces the same effect.
>
>Dr. Resonance
>
>
>
Hello again,

I feel as if maybe ive got my signals crossed with something.  Lets define 
racing sparks, and the problem that i HAD.  Racing sparks occur at random 
throughout the secondary coil.  Perhaps an arc that travels from a point at 
1/2 the coil lenght, to another point 2/3 of the coil lenght.  Is my 
interperetation correct??  Now my problem was that the very top winding of 
the coil arced the entire lenght down the coil to strike the ground 
connection of the secondary.  Is this understood to also be known as racing 
sparks??  It seems that this problem is simply lack of insulation (secondary 
not long enough to handle voltage) and perhaps the lack of field formation 
desired by a toroid(since i use a sphere).  I do realise that the posts are 
becoming more of argueing about the effects of overcoupling rather than the 
problems with my coil.  This is perfectly fine since my coil seems to be 
operating just fine and i dont need the help.  But reading these things is 
where the real learning comes into play.

Steve Ward.