crank position sensor

[Ord Millar]

36 teeth with one missing is pretty typical.  A variable reluctance sensor
can be used.  If you can't find one for engine application, maybe an ABS
sensor would work.

You can also get industrial type proximity switches, these already have the
amplifiers built in so a nice digital type signal comes out.


-----Original Message-----
From: owner-diy_efi at efi332.eng.ohio-state.edu
[mailto:owner-diy_efi at efi332.eng.ohio-state.edu]On Behalf Of Tom Parker
Sent: Friday, February 05, 1999 6:52 AM
To: Diy Efi
Subject: crank position sensor


Hi,

As I've mentioned before, I'm thinking of building an ignition control
computer for my Mini. I plan to use the Tim Drury article as a basis.

My Mini engine does not have a crankshaft position sensor. I need to
fabricate
or buy a toothed wheel and aproprate sensor. Then I have to mount it
somewhere.

I've been thinking. The flywheel already has a ring gear for the starter
motor
on it. Could these teeth be used? There are somewhere in the region of 100
teeth on it, (I'm not going to count them accuratly yet). They are 9mm apart
and the ends are 2mm thick.

What sort of sensor could detect these?

With a top engine speed of 8000 rpm, there would be around 14000 teeth going
past every second, thats 70 micro seconds...

I can make a divider if the computer can't keep up.

I would have to use a sensor somewhere else to detect TDC, but that
shouldn't
be too dificult.

How many teeth are necessary? I could

--
Tom Parker - tparker at nznet.gen.nz
           - http://www.geocities.com/MotorCity/Track/8381/