Im trying to drive a CDI unit used in an old Porsche 911 as ignition device
via an arduino.
the CDI needs as trigger an external zero crossing inductive signal (see image below)
The inductive signal is generated by a coil witin the distributor which comes with a rotor/stator.
The actual signal measured from the trigger signal line between the distributor and the CDI looks like this:
I've read many postings in the internet an it seems that the CDIs internal circuit needs the signals change from positive to negative as trigger.
Here you can see the wiring from the distributor to the CDI:
Here you find complete CDI diagram. The terminal here for the incoming inductive signal is "7".
I see this signal does not drive the Thyristor/SCR directly but via a transistor BCY58X?
My target is now that I want to achieve with an arduino ...
1. read the inductive signal from the distributor
Here Im aware of the needed protective circuit for spikes and negative voltages: http://andrewcologne.bplaced.net/911/CDI/arduino-protection.png
This signal will then be interpreted and via an internal routine "delayed" so I can affect the ignition timing.
2. send an "inductive like" signal (like seen in the image above) from the arduino to the CDI.
Here Im aware that a zero crossing VR signal is needed generated by the arduino
How can I generate with an arduino such a needed "inductive like" zero crossing signal?
Thanks a very lot for your help!