Ray,
my questions were for the people doing the evaluations and comparisons between CDI and LDI,
the energy in a capacitor is 1/2 C V^2, the energy in an inductor is 1/2 L I^2, these are computable,
measurable, and knowable, but no one seems to be doing it.
the resonant frequency of an LC circuit is 1 / 2 PI sqrt(L C), again this is computable, measurable,
and knowable, and while this is sometimes being observed with a scope it isn't being compared
across designs.
so the questions still are, 1) why do CDI seem to generate short sparks, and 2) why do CDI seem
to deliver only a fraction of their energy to the actual spark (where does all the rest of the energy go)
we need to have a handle on the absolute minimum basic question like how much energy are we
starting with when comparing CDI to LDI, and how do the ring down frequencies compare, and think
about what else could be making a difference. I see circuit diagrams for CDI using SCR, and LDI
using IGBT, but they are both 4-layer devices and the difference seems to be in the gate rather than
in the power diode, so I'd like to better understand the difference in power handling rather than
what sort of trigger they require. One thing that puzzles me is that neither design seems to have
a "free wheeling diode", so how does the primary ring down without an AC circuit.
another thing on my mind is from back in an earlier life when I toyed with tesla coils, there were
lots of people working on models for the resistance of a spark based on instantaneous and
average measurements of coil power, a complicated subject due to the non-linear, and even
negative, resistance of the spark. the question being is a spark plug arc similarly complicated.
Peter.