ION-related IGN Comments & Coil Quest

[garfield at pilgrimhouse.com]

Hey Maties.

I had a brain-flash (or fart, we'll see shortly) whilst looking over the
DSE schematics for their CDI plans/article.

[SIDEBAR: the circuit and assembly is DIRT simple, and looks well thot
out and done (true, the pc board is a disappointment cuz of it's size,
but they wanted one you could do at home, I guess. Me I'd cram it in
niceNtight on a piece of two-plane thru-hole 0.1" perf board), and the
only "custom" part is really doable with anyone with two hands and half
a brain-stem; it's the main inverter transformer, and the plans call out
all the particulars and part nos. for the bobbin/core and other pieces
from Philips you need to buy to assemble this "custom" transformer. The
parts list is quite detailed in that respect; major kudos for that.
Sooo, nuthin esoteric or hard about this one "custom" transformer.
Sounds daunting but it's really a pieceOcake no-brainer.]

The guy's design (John Clarke...anyone on the list from Oz know him,
BTW?) is for use with stock IGN coils. So while tryna think-out an ION
circuit that doesn't need HV diodes, and still can use the stock coils,
and having troubles seeing how that's EVER gonna be possible, the thot
struck me... HEY, I'll ask all them bloaks on diy_efi if ANYONE has ever
seen a so-called 4-terminal stock auto IGN coil? What I mean by that is,
consider the normal IGN coils we're all used to. They're basically a
3-terminal device; one terminal is the HV output (the "top" of the
secondary, if you will), and then there's a "shared/common" connection
for both primary and the other side of the secondary, and then the third
terminal, which is for the primary feed. So you essentially have what we
used to call an auto-transformer, or a transformer with a common
connection for both primary and secondary.

Now, what would be REALLY ideal for ION is a stock automotive IGN coil,
but one that has it's primary and secondary completely independent (no
common'd terminal), so you have a 4-terminal device, with three pins on
the low voltage connector, and one for the HV secondary output.

So, there's the bottom line question, maties; anyone every seen such a
beastie? I and my Napa pal went through our books and his inventory this
afternoon, even called Echlin, but couldn't come up with anythin. Of
course, we don't give a rip what shape or form it's in for eXperimental
purposes, but I'd sure be grand if a real "in-situ" coil existed we
could also use with the real ION. Ask around, see what you can come up
with; I'm certain that IF such a beastie exists, sooner or later someone
on the list will exhume it!

Meanwhile, I'm still slowly working on my "patent commentary" and
example circuits, so it's comin.

Hey, BTW, I had another somewhat bizarre thot, incase we CAN'T find such
a coil to play with, that even with box stock IGN systems, and NO mods,
one could actually build some lil adapter blocks that went between the
HV lead and the plug top, and using some few HV diodes (there's nuthin
wrong with them, BTW, they're robust and failsoft, it's just that I'm
stuck on being able to do the "elegance" thang like Saab did, where THEY
don't need any atoll), you could ADD the ionization detection into an
existing IGN system, on a per-plug basis. I see absolutely nuthin that
would prevent this, EXCEPT we still don't know if the longer spark
duration of inductive IGN is gonna "blank" critical portions of the IGN
phase. But, yeah, even the idea that MikeMorrin suggested might be
possible, in that these "inserted measurement blocks" could actually
quench the "tail" of the inductive spark early and MAKE a window for ION
to do it's measurement magic. That too might be possible.

I only mention this possibility because IF we could make this work, if
only for eXperimental purposes, it would allow dyno tuners and others to
LEAVE their acoustic knock detectors on the engine, and COMPARE the
"indicator and measurement" functionality of one vrs the other, and
REALLY determine if ION is giving you anything back. The reason I
mention dyno tuners in particular is they have the easiest time in
dialing in a forced "knock" on command. The rest of us have to tweak
timing manually, and be careful we don't overdo it with load and
throttle. I know there are several guys on the list that could do this
comparison, so this too is another avenue of eXperimentation. Here, I
don't think the "ionization circuit" per se is the
difficult/questionable part, but rather what to do with the stock
inductive IGN system's spark duration.

Thas all fer now. Scan yer personal archives and see if you've ever seen
a "4-terminal" IGN coil. Any feedback appreciated.

Gar