Re: Distributor -Reply

[Kenneth Scott <KSCOTT@HOLYCROSS.EDU>]

The coil is a large inductor whose magnetic field stores
energy until it is changed (by the breaking or openiong of the
points).  The collapsing magnetic field in the primary circuit
caused by the cessation of current due to the opening of the
points causes a large voltage spike in the secondary, hence,
spark.  Most CD electronic ignitions work, I believe, in the
opposite way.  The coil is normaly non-energised and the
spark is generated by dumping the contents of a capacitor
across the primary of the coil at the time the spark is
desired.  I do not know how other electronic ignitions work.
Ken Scott  77 MGB