Ignition question

[Carl Summers]

bruce plecan wrote:
> 
> This may sound really dumb, but I gotta ask.  In a CD ignition system
> they "dump" a 1 MFD. cap (at 200-300v) thru the primary side of the coil.
> The reason I was told DC is to begin the arc at the plug on a specific
> electrode.  In a distributorless ignition it looks like it doesn't
> matter.  So why not just pulse the CD charge transformer thru the ign.
> coil for say a little over a millisecond.  If the answer causes smoke
> just e-mail me, and I'll put my hand down.
>   TIA Bruce  nacelp at bright.net

Bruce,
I may be misunderstanding your querry,,but here goes......The Cd
releases a high energy short duration spark that is very stable to high
rpms and if the cap is overloaded it will multispark at low rpms(such as
msd's do)  What I understand the DIS to be is an inductive storage(I
could be wrong please correct) While the inductive storage can drop off
energy with rpm It was understood by me that because of the multipack
coils the mj output would not drop off till after 8000rpm on an 8 cyl
application.  Even though the mj output of the cd and inductive storage
might be equal, the inductive storage has a longer duration spark less
intense...(cleaner emissions)
              +
             +++
             +++                             +
             +++                            +++
             +++                           +++++
            +++++                         +++++++
           +++++++                       +++++++++

              CD                      Inductive storage
Even though the Millijoule is the same the spark is different......
(but I still think I missed the point) anyway HTH
Carl Summers