Re: Tesla Secondary Voltage

You wrote: 
>Does anyone know approximately what the secondary voltage is on a coil 
>is producing 5 to 6 feet of spark?  I have seen some discussion on 
this but
>never seen any numbers.  Is it like 2 million volts?

The maximum theoretical output voltage which is generally unobtainable 
from any Tesla coil is:

             Vsec = Vpri * sqrt(Ls / Lp)

With the usual components people use, 60-70% of this value is doing 
well.  If you want to see the "true" spark length of your coil, press 
your ZAP button for an instant.  The discharge you see is more like the 
real thing.  It is because Tesla coils stay on "continuously" that we 
get good air channel heating and ionization which allows the spark to 
grow.  Spark length, therefore is more indicative of power than 


Don't be too disappointed when you put numbers into the above formula.  
My big coil does 25ft and I'm still working on my first million volts.