( QTY 3 ) Bi-Directional Optical Motion Sensor Assembly

Here's an interesting device with a wide range of electro-mechanical possibilities.

This optical interrupter differs from the garden variety in one significant aspect: It has Dual Detectors. Together they can be used to sense direction or make an up-down counter. If you look at the test schematic you will see two outputs. In our lab tests, I took a strip of cardboard and cut slots 1/16" wide spaced every ¼ inch. Sliding the strip from right to left, LED A was predominately on, toggling briefly to B as the thin slot passed through the gap. Reversing the direction, LED B came on predominately and toggled briefly to A as the thin slot passed through the gap. Really simple. I used a strip, but a slotted or painted dial (not included) attached to a shaft or knob could just as easily be used.

Measured Output Levels: VLOW = 0.3 Volts, VHIGH = 3.3 Volts
Sensor Gap Width: 1/16"
Connector: FFC 5-Position 1mm-Pitch

The interrupter is mounted to a circuit board with a 0.1µF bypass cap, 150 ohm resistor (for the IR LED source) and connector. Mounting tabs are on the molded plastic sensor. The circuit board can even be discarded if space is critical. For our evaluation, we removed the connector and soldered solid copper wires through the holes to the pads.