Electronic Ignition Explained

[ndutton]

With the recent spate of overheating coil reports I went on a quest to learn more and stumbled upon this, the best treatment on gasoline engine ignition systems I've ever read. The second half discusses electronic ignitions. As you're reading along, the induction type ignition pertains to our engines, the Hall effect sensors are the Moyer and Pertronix systems, the optical is the Indigo.

Coil function/performance is also discussed as is the reason for various coil resistances. There's a mention of the "toaster" effect with coils too. I poured over this for at least a half hour, felt it was worthy of posting.

Electronic Ignitions 101

[Mo]

Good read.

Neil,
Bang on the money my friend. Wow, that's a good find and well worth the read. I just found out (remembered) stuff I'd forgotten but knew as a young fella messing with these engine. I'm impressed.

[norahsark]

Appreciated - explanation of ignition systems well presented. I am sure it will help me understand the system on my A4.

[ndutton]

Please note that some of us are using a ballast resistor for reasons entirely different than described in the treatment. Our resistor use is to control system amperage to meet the desired specification, NOT to enhance spark energy during starting.

It's also interesting that the treatment uses the 12 volt figure in their mathematical examples when in reality it's between 13.8 and 14.4 roughly at cruising RPM with regulated alternator output providing the voltage.