ignition reference

[Sandy]

[Snip]

>Two quick points here, firstly I'm pretty certain that a VRS sensor
>won't trigger with a plastic wheel, 

They won't, but for those that may want to try making a simple LED Beam
Breaker, the can use that method with a plastic wheel.

>Secondly, you may find that the type of wheel that will interface
>sucessfully with any given ECU in terms of teeth thickness, teeth
>size, inter-teeth gap and mark-space ratio, is a function of the
>VRS input circuitry in that ECU. For example, if the teeth are too
>close together you may fail to detect a good clear zero crossing at
>high RPM. 
>

I thought they were trying to make the whole thing from scratch, not to
interface to an existing ignition system, if that were the case, they could
just use the stock interrupter or what ever the trigger is.

>In essence, I'd be very surprised if it didn't matter what shape and
>size the wheel is. 
>

Much stranger things have happened, some thing work with a wide lattitued
for errors, but I would expecte that anything I am working on will not have
that kinda' luck ;-)

Sandy