Coil Quest Over (or just postponed?)

[garfield at pilgrimhouse.com]

On Thu, 04 Jun 1998 07:15:46 +1200, Mike Morrin <mikem at southern.co.nz>
wrote:

>At 08:28 3/06/98 -0400, Clare Snyder wrote:
>>Just had an idea on the Nissan coils - anyone check them for continuity
>>at, say, 80 volts? Mabee, just mabee, they have a HV diode stack in
>>them?
>
>I think (although I was wrong once), that these (and some other
>distributor-less coils) have a series spark gap in them to simulate the
>effect of the distributor rotor to cap gap.  This has the effect of
>sharpening the voltage rise time at the plugs, making them less prone to
>fouling.

Yup, I agree, that's probably a much more likely scenario than some HV
diodes inside, those take a fair amount of room and I'm not sure what
purpose they'd serve. I think it was just a guess on Clare's part,
another remotely possible explanation. That's why I wanna get my hands
on one and take it apart. But this is OBVIOUSLY not a burning issue, so
no biggie.

The one thing, IMNSHO, that seems to point with high probability to the
cap thingee, is that someone else (or was that you Mike?) also mentioned
some Bosch coils being the same way (i.e., having an internal gap), and
since I recently metered a bunch of Bosch coils and found no DC
continuity in their secondaries either, it seems likely both coil types
work the same. And it wouldn't be the first time a Japanese company
followed Bosch's lead. B)

Just some itinerant thots.

Gar