German ZF gear speed and direction sensor
The German ZF gear speed and direction sensor SD101201 has two Hall effect sensors; one detects speed while the other detects the direction of gear movement. The output is an open collector transistor. When the leading edge of a gear tooth is sensed, the speed output becomes high (open), and when the trailing edge of the tooth touches the standard target, the output becomes low (closed). The direction of movement is sensed by the leading edge of the speed sensor; for clockwise rotation, the direction output becomes high, and for counterclockwise rotation, it becomes low.
