Photointerrupters are devices that detect rotation or linear movement by sensing interruptions in a light beam between a light source and a detector. They combine optical transmitting and receiving functions and are commonly used in vending machines, copiers, and printers. The HOA0880-T51 from Honeywell features accurate position sensing with a phototransistor output. This infrared photoelectric sensor is housed in a black thermoplastic casing and offers options for detector aperture and housing transparency. It includes a built-in strain relief to ensure strong wire attachment.