Blake,

For a decent description of how the ignition system works, point your
browser to

<http://greenmini.mrbean.net.au/~rover/ketterin.htm>

Replace points/condensor with hall effect sensor and amplifier and you
have it.  Essentially the hall effect sensor/amplifier replaces the
mechanical points with an electronic switch.  But the basics are on the
above mentioned page.

Jim Arnott
WetWesties
Union, OR