I'm new here, and I've only been studying electronics for just over 1 year. So forgive me if I am out of context.
I've been studying the schematic Rev2C and have a couple of suggestions.
1) I think D9 should be a 5 volt Zener.
2) I think you should use a Schmitt Trigger on the comparators U8A and U8B.
Schmitt trigger - Wikipedia, the free encyclopedia
