Light Barrier Sensor

An infrared emitter and receiver facing each other across a small gap. Anything passing through the gap breaks the beam and produces a clean digital transition, making it the standard way to count objects, detect a limit position or read an encoder wheel. Because it senses through-beam rather than reflection, it does not care about target colour — a matt black object triggers it exactly as reliably as a white one, which is where reflective sensors fall down. Through-beam sensing works regardless of object colour; Clean digital output ready for interrupt counting; No contact, so nothing wears out; Common for end-stops and encoder wheels