Why I wear Cone Shaped Hats ie ?Mr Hall

[Mike Turner]

Sounds like an inductive pickup. When flashing, was any power being applied
to the sensor or was it just dangling from the two wires from the LED and
resistor (my guess)? The Hall effects I'm using sound very much like the
one's Al's describing. Power and ground are needed for any output. Hall's
need power since the Hall effect is teeny tiny small. The actual effect is
the result of a magnetic field on current flow in a conductor. If the field
is oriented in the correct direction, electrons will be pushed to the side
of the conductor or perpendicular to the direction of current flow.
Measuring the EMF across, not along, the conductor is what the Hall sensor
does. Right hand rule, B vector dot product with the E vector, and all that
other good EE stuff. The ABS wheel sensors on our vette appear to be Hall
effect. Witness the accumulation of iron dust all over the rubber boot on
it.