Optek Through Beam Photoelectric Sensor, Block Sensor, 3.2 mm → 8 mm Detection Range

This series of slotted optical switches, from Optek Technology, consist of an IR LED and an NPN silicon phototransistor. They sit within a black plastic housing, mounted on opposite sides of the slot. The OPB827 and OPB828 are designed for mounting on a PCB whilst the OPB829Z has 24 inch AWG wires.
The phototransistor switching occurs when the IR LED and phototransistor are interrupted by an opaque object passing through the slot. Suitable applications for these slotted optical switches include; non-contact object sensing, assembly line automation, machine automation, equipment safety and machine safety.

Slotted Optical Switches, Optek Technology