I have been following this thread with some interest and based on the most recent posts I think I am ready to bite the bullet. First let me say that the intended application is an RC airplane engine (CRRC 50cc). The 300 to 9700 rpm range is spot on. Based on previous postings attached is a schematic of the circuit I propose. I have a few questions for the RC guys.
1. I am considering building the timer board and power board separately. The timer board would be in the receiver compartment and powered from the receiver batteries. The power board would go up front with its own battery. Any comments?
2. Has anyone encapsulated the boards in epoxy"
3. I haven't been able to figure out where pin 4, 12 and 13 go on the PIC. Can anyone help?
The timer board can draw power from the HV ignition board so no need for a separate battery.
The closest thing I did was dip the whole thing in polyurethane. Once dried it will keep the parts from vibrating loose.
Is there any way for you to make post more clear schematic?