Help on Inertia Dyno Project

[Kickaha]

there is a Kiwibiker who has been down this path and built his own dyno

I think it is Geoffm

[bogan]

Would using RF be a silly idea? Read somewhere online a post refering to using an AM radio off station.

I get the feeling it'd take more work to get that right than an inductance clamp would be.

I have a circuit, read closely some references from a picaxe forum and thought about hacking an old timing light for parts. Where else could I source a purpose built inductance clamp?

Not too sure where you could get a ready made one from, whats the circuit like though, maybe simple enough?

Yeh good idea with the timing light, an inductive pickup one would be exactly what you want

[jonbuoy]

What about a frequency counter on the alternator? Believe some diesels use this for tacho output, even better on a bike as theres no belt slippage. All you need then is a couple of crocodile clips (tap in before or at the rectifier) maybe enough ripple on the battery terminals to trigger it - I used the frequency mode on my Fluke when I was fault finding my reg/Rectifier issues. If you get a frequency counter or make up a circuit with a sensitive enough gate (or an RF frequency counter) you can probably get away with wrapping a wire or making up a small clamp on transformer around the spark plug leads to trigger it. A Tacho is just a frequency counter. You could take a punt on one of these and tap into the circuit somewhere along the line to your datalogger, that way someone has already done the tricky analogue stuff for you.

http://www.jaycar.com.au/productView.asp?ID=KC5440