Hi Andreas
On Sun, Aug 26, 2012 at 7:56 PM, Andreas Hahn <andreas.hahn@xxxxxxxxxxx> wrote:
How do I go about calculating the output voltage of the secondary coil in my
SSTC?
The voltage will be low for most SSTCs. My measurements of some of my
coils showed that as little as 65kV could produce over 4 feet of spark
under the right conditions. Most SSTCs wont break 80kV, and the peak
will most likely be at the start of the spark cycle, before there is
much plasma to load down the output of the coil.
Vprimary * sqrt(Lsecondary/Lprimary) produces numbers that seem much too
low, which is consistent with comments elsewhere that method only applies to
SGTCs.
I think you also need the coupling coefficient in there, but im too
lazy to work out the math for you. Instead, id suggest measuring the
current coming out of the bottom end of the secondary, and using the
coils impedance to work out the voltage. The coil impedance is simply
Z = 2*pi*f*L, and ohms law V=IZ, where L is the un-coupled part of the
secondary inductance (look up mutual inductance for the maths). This
also makes the assumption that the current through the entire
secondary winding is the same, which is not true due to the
distributed capacitance along the coil length (so the bottom of the
coil will carry more current than the rest).