Unfortunately, www.jerry-howell.com is not currently available (I hope it's only temporary). [sm=crying.gif]

The good news is I have another site bookmarked with circuit diagrams of the Tim4, Tim6, and Tim7 ignition circuits, based upon 12V. By changing the component values, it should work with lower battery voltages. This person is using them for a homemade radial engine.

By the way, he also documents how he built his own spot welder... Scary stuff [sm=stupid.gif]