Guys some of you may have read the series 2 digital speedo thread and the rev counter problem
Basically it a 4 stroke rev counter that can not be changed
It is supposed to take its rev counter pickup from the Green from the CDI and of course you have a handy green coming to the headset from the CDI. Everything works but its over reading the revs as its doubling up the count.
It seems rev counters work in different ways some use a inductive pickup (wire wrapped round the HT lead) and the spark triggers the gauge, This one uses High voltage from the CDI.
I am trying to get my head round how it picks up the signal.
My understanding was that the stator provides an AC charge that is used to charge the Capacitor inside the CDI The pick up triggers the discharge so does the voltage drop at the firing point and is this drop in voltage what is been picked up. As those who have ever grabbed hold of the green know it puts out a hell of a kick.
I have tried a powered inductive pickup using a 12 volt DC feed, a transistor and a few resistors and get lovely pulse for each spark that will light a LED, but no rev counter. my thought was that if it works on low voltage (12V) I can use another form of pickup say off the flywheel, but that looks like a no go.
Can someone explain how they think this rev counter is working, and the output of the green from the CDI, in fag packet terminology.
