Electronic Ignition

Not open for further replies.

Thread Starter


Joined Feb 7, 2012
Hey everyone,

This is my first post, so I'll go ahead and introduce myself. My name is Matthew and I'm a computer programmer by trade. I'm in my early 30's and I'm most way through restoring an old Honda motorcycle.

I've been wanting to learn more about electronics but I'm the kinda guy that needs a practical application of something before I'm able to learn it and stick with it.

With that in mind, my first electronics project is going to be to replace the old mechanical points and advancer unit in my bike with something electronic. Being a programmer in my day job, I've decided to make use of a PIC microcontroller to take care of the timing and delivery of the spark.

I think I'm off to a good start with my circuit design, but a friend of a friend mentioned that I should make some changes with my initial design.

First up, I found this circuit online that is meant to keep the flyback from the coils from cooking my PIC:

I was told that I can do away with this circuit (and the 5V relay that controls it) and replace it with an IGBT. I did a bit of Googling and I can't seem to decide which IGBT will suit my application. Furthermore, is it really that simple? Just connect the IGBT directly to the output of my PIC and then connect the load on the coils to the IGBT?

Any further explanations and/or reading materials would be very much appreciated. An explanation on how to choose the correct IGBT would be great, too.

Thanks in advance,


Joined Mar 24, 2008
The All About Circuits forum Administrative Team has elected not to host discussions of automotive electrical system modifications/enhancements due to safety concerns, the potential of legal ramifications and the possible circumvention of vehicle regulations at the state and federal level.

This thread is against the AAC forum rules, Chapter 6, as seen here:


Automotive modifications of any kind are strictly forbidden. Therefore, this thread will be closed.

Please try to understand the reasons behind this action, and feel free to browse and use the forums.

You might find answers to your questions in one of these forums:

Not open for further replies.