MS1 V3 Drive two coils (Ford Coil Pack)

[Michael]

I've just received my MS1 V3 kit and am exploring the options. Most are quite straightforward, but I am a little confused about the entry in the manual entitled, "Two Coils Direct Drive Output for a V3.0 PCB". A schematic diagram is shown based around and LM1815N, but no reference seems to be made to this in the text. What is the significance of this circuit? I understand the need for two VB921s (or BIP373s). I suspect that it is something to do with VR detection, but there is a perfectly good VR detector given in the schematics as "Megasquirt - Tach input". Is it an extra one for a cam sensor? (which I don't intend to use) Am I missing something or can I ignore this circuit?

Many Thanks - Michael

[psucrash]

Tach and cam input are a separate circuit all together from driving coils directly. Direct driving the coils (usually) used D14 and D16 as output in wasted spark mode. You then connect a 330ohm resistor (one per LED) from the top of R26 and R29 to the base of the transistor that will be driving the coils (VB921 or BIP373). If you are using an external ignitor then you can just send the logic signals off the 330 resistors to a spare output.

[Michael]

Thnks vey much for that - I think I've got it figured out now - Michael.