Yep I'm living/working in the wrong place, the aussies certainly get creative Then again right in font of me now I have the circuit diagram for our gun modulator that we run at 300 pulses per sec but will cope with 2000 pps and as my DD bike red line is 9k thats only 150pps then I think I have most the parts I need here at work.
As I mentioned I could spend the money and fit an Elliot or use the Stack I already have, but its not in keeping with the project.
I have just had the 916 revcounter working on my 600SS, The bike ran fine but the circuit still needs some Select on Test (SoT) resistor changes. At tickover it was reading about 400rpm and at full engine speed it only got up to 7000rpm. Not a bad first attempt. I haven't yet measured the revcounter pulse on my 916 to find what level so on the prototype I went for a 6v pulse, this could be either 1 volt more than required or 4 volts less than required.. If I can find a suitable variable resistor I will put it in the circuit to allow me to experiment with differnt voltages.
oops, Now going backwards, I haven't got that much of a choice of resistors at home so I used what I had, firstly I went for bigger voltage pulse to the tacho, this gave no reading at all. So I then went the other way so I had about a 3 volt pulse going to the tacho, this caused the engine to run poorly, the tacho needle to jump about and then after about 30secs fried the chip in my circuit and melted the base it was plugged in to. It looks like the original voltage of 6v was the closest and it may be the pulse length that is the reason the readings were falling short of what I expected.
Prototype 2 is now at the design stage, but I doubt if it will progress much over the weekend due to a lack of componts at home.