injection sensor from an AAZ pump used for a revcounter pickup????

[regcheeseman]

The Yellowjacket says that the yellow/white wire is the supply line (+12V) and the grey/white wire is the signal line.

It does? It definitely says 12v feed? Just want to make doubly sure before I toast something. Shame if it is 12V because my PIC controller circuit only has a 5v rail.

I used to  work for Beran designing online vibration monitoring systems for (amongst others) nuclear generating sets, so I've a little experience of interfacing with industrial spec transducers. But all the trans I worked with had the signal conditioning at the amplifier end, not on the piezo transducer.

Oh and you'll find that 4000 rpm produces a 266Hz signal - nothing like 8K - I'm using PWM signals to simulate an engine running for my test bench.

edit: My maths is wrong too.... two pulses per engine rev so that's a 532 HZ signal, thanks for making me go back and double check.

[regcheeseman]

Always the cynic, my intuition told me that the sensor fitted to uk pumps appeared to be a pressure switch with no internal signal conditioning.

I arranged for a friend to meet me at the pub and to bring his wife's unmolested AAZ.

After the anticipated banter for me working in purple nitrile gloves I connected up the multimeter.

5v was present at both terminals with the engine off (also with the ignition off)

Starting the engine and 5v remained on the yellow/white wire but there is now a signal on the green/white wire - I'd guess a 5v square wave. Switch to frequency measurement and it's about 32Hz, blip the throttle sees it rise to 80Hz

So there you go, maybe it's UK specific but it's a normally closed pressure switch fed with 5v

Quite easy to convert this signal to drive a standard revcounter - watch the VNT controller thread....