It’s happened to many of us – one day you are driving around in a perfectly serviceable if older vehicle and then it quits on you, or it simply won’t start the next morning. You take it to your local friendly mechanic who tells you that the ignition module has failed and will need to be replaced but because of the age of the vehicle (and possibly its overseas origin) the repair job will cost you many hundreds of dollars.
But because you are a SILICON CHIP reader you have a big advantage; you can build this substitute module for a fraction of the cost. Or maybe you have an older vehicle which has the old points ignition and you want to upgrade it to electronic ignition. Once again, our new module is the answer.
This new high-energy ignition suits vehicles with points, Hall effect/Lumenition sensors, optical sensors (eg, Crane & Piranha) and reluctor pick-ups. In fact, it will work with virtually any ignition system that uses a single coil, even those controlled by an engine management computer.
• Multiple trigger source options
• Trigger invert option
• Adjustable dwell time
• Option for output to follow input
• Spark test mode
• Tachometer output
• Adjustable debounce period
• Dwell compensation for battery voltage
• Simplified design using ignition IGBT to switch the coil
• Coil switch-off with no trigger signal
Better & simpler
We’ve improved on our previous 2005 design in a number of important ways. The main change is the use of an IGBT (insulated gate bipolar transistor) ignition driver. This features integrated protection and is the type of device used in virtually all new cars.
The Darlington transistor used in the older design was not only larger and more expensive but required a string of zener diodes to protect it against the high-voltage back-EMF from the ignition coil. Plus it required extra driving circuitry, some of which was bulky, that the IGBT simply does not need. The resulting much smaller module will be much easier to install, especially in motorcycles.
We have also built a self-test feature into this unit which means you can do a bench test to check it’s working without needing a signal source to drive it with. Similarly, it can be used as a stand-alone ignition coil tester.
As with the High-Energy Ignition System from the December 2005 and January 2006 issues, this one also uses a PIC16F88 microcontroller as the “smarts” but naturally we have also improved the software.