Draft for engine ignition module (the one that drives the coil). It is basically a power switch. I decided to use BU323Z transistor, because of it's internal protection (it is very tough, and can resist some abuse). Still not tested, but even if it was - use at your own risk. SMD version, with BU323Z as TH exception, as it's intended to be mounted on external heatsink (or metal case to be used as heatsink). My intention is wires to be soldered directly to the PCB, as I beliveve this is far more reliable in high vibrations environment than any connector you can imagine.