Allegro ats667, gear sensor, has built in magnet, needs a couple caps and a pullup resistor, I used all SMT parts soldered direct to the legs and potted the whole shebang in a short bit of nonmagnetic tubing and filled w/5 min epoxy.
It wants to see a filled missing tooth, rather than a cut out missing tooth, it will see ~garbage with a cut out tooth, and work perfect past 16K shaft RPM with a filled tooth. (has built in AGC circuit the missing tooth apparently jacks with)
I have about 5 minutes work in the next two pics:
Here's the next one about to go together.
(has been on my desk buried for months)
Setup in the car is ~identical, except for a 36 tooth wheel.
I originally bent this up/made this as an "extra" it to fit in the 3/8" tube, so I'll roll with it.
There's a 50v 1uf, .1uf and a 5k pullup resistor on the legs.
(The .1uf could be mistaken for solder splashes on roach crap)
It will work from ~3-30v. and is reverse polarity protected internally.
DIY-ats667-hall-sensor.JPG
And just to show it fits, 32 pitch steel gear is light press fit on 3/8 brass tubing...Haven't "filled" in the missing tooth yet.
72-tooth-in-009.JPG
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