Driving CDI coils directly from Microsquirt
Posted: Sun Sep 14, 2008 5:34 pm
G'day all,
My V-twin motorcycle uses four CDI-type coils to fire two plugs per cylinder. Timing is from a pair of VR sensors on the crank. The two CDI units are powered from two magneto-type coils (one per cylinder), generating about 200VAC.
It looks, from a quick look at the the datasheet, that the VB921ZVFI drivers are capable of switching this kind of voltage. So would it be possible to put together a CDI driver something like the diagram below (per cylinder), using only a few external components?
Or is the CDI impulse current too high for the driver? It'd be nice to be able to drive the stock coils with a minimum of extra parts ... Apologies if this is explained somewhere in the docco, I couldn't find any mention of it!
-----Nick 'sharkey' Moore
My V-twin motorcycle uses four CDI-type coils to fire two plugs per cylinder. Timing is from a pair of VR sensors on the crank. The two CDI units are powered from two magneto-type coils (one per cylinder), generating about 200VAC.
It looks, from a quick look at the the datasheet, that the VB921ZVFI drivers are capable of switching this kind of voltage. So would it be possible to put together a CDI driver something like the diagram below (per cylinder), using only a few external components?
- cdi_maybe.png (28.49 KiB) Viewed 1816 times
-----Nick 'sharkey' Moore