Originally Posted by
Cat 1
John,
Your project sounds impressive and I would like to try one when Its avalible. I admire your effort in this as I know the work involved in creating a reliable ignition system. I played with this back in the day and had a very robust fixed ignition unit developed that I utilized "straight up" or with mechanical advance to do "weedwacker" conversions. My project ended when I got frustrated trying to solve the electronic advance - Packaged development boards were not here yet and PIC programming was my Nemesis. I spent many hours hand winding experimental toroid transformers and coils.
I'll let you know when I get ready to release them.... PIC is what was used in the original CH ign systems back when Bill Carpenter first introduced CDi to the hobby... todays arduino are even more capable... the method of advance is a diminishing delay time over rpm, down to zero delay, puts your ign timing advance at your static base timing you set the engine up with... the CDI electronic circuit is your basic stepup transformer, charged capacitors, discharged into a mult-wound ign coil... nothing elaborate really... A typical handheld BBQ spark Ignitor works in a similar way, ours has better quality components of course, and a higher voltage output... the cdi is internally regulated of course, 2s 6.6v LiFe minimum required, 3s LiFe, or LiPo will work just fine.