No - that's one of the geek-speaks I was referring to in the earlier post. Actually, it's a fairly simple term, once you recognize that the alternative to 'direct coil control' is...... 'indirect coil control'. If the coil is triggered by the ECU>ignition module>coil, that's 'indirect coil control' because the ECU triggers the power transistor and the transistor triggers the coil, although it's never referred to as such in the manuals. If the coil is triggered directly from the ECU, that's 'direct coil control'. Simple, eh?

Not really....... if 'indirect coil' control is chosen, you have to figure out if the square wave signal coming off the module is inverted and what dwell setting is designed into the transistor.... so there's another issue down the road in configuring the ECU to use the falling or rising edge of the square wave signal as the trigger. <img src="/forums/images/graemlins/rolleyes.gif" alt="" />

With an optical sensor, direct control is suggested for simplicity - but my cause for worry is the amount of current required within the ECU trigger circuit - you have to build an extra circuit to handle the load.

I'm concerned with the possibility of coil burnout if the ignition is on and the engine isn't running for a while. I've blown up one coil in a boat that way by not using a dropping resistor to reduce power at the coil... it wasn't a pretty sight with oil everywhere and the possibility of a bilge explosion/fire was downright scary.

Anyway, just as I thought I had the MS issue limited to two choices for coil control and all figured out, I discovered that I could use the 'direct coil control' high current driver circuit to trigger the ignition module, in effect giving me a high current indirect control. <img src="/forums/images/graemlins/lol.gif" alt="" />

Man-o-man......... <img src="/forums/images/graemlins/evil.gif" alt="" />

Frank