LS4EL - 

LS4EL/RL Light Screen Systems offer a simple, economical, but highly reliable means of sensing objects moving at high speed through an area (or “window)”. Each system consists of two self-contained units: An emitter and a receiver. Emitters contain four infrared light sources aligned in a row and strobed (turned “on” one at a time) in a specific sequence and at a high frequency. Receivers contain a matching array of phototransistors. The height of the array is 3.5 inches (90 mm). The LS4RL receiver may be placed 18 to 90 inches (45.7 to 228.6 cm) opposed from the LS4EL emitter. This produces a “curtain” of light 5 to 6 inches high and as wide as the separation distance between the emitter and receiver. ”Features:

Emitter and Receiver Pair Produce a Strobed Array of Modulated Light Beams to Produce a Light Screen

Simple, Economical and Highly Reliable Means of Sensing Small Parts Which Pass Anywhere Through the Light Screen

Light Screen Area Measures 90 mm (3.5") High, and as Wide as the Distance Between the Emitter and Receiver

Fast, 1 millisecond Response; Output Includes a 5-millisecond Pulse Stretcher for Interfacing Reliability

Tight Beam Spacing for Sensing Small Parts as Small as 5.6 mm (0.22") Diameter

Totally Self-Contained; Very Rugged with Totally Encapsulated Circuitry

Bipolar Design Offers the Choice of NPN (Current Sinking) or PNP (Current Sourcing) Outputs from the Same Receiver; Both Outputs May Be Used Simultaneously