Photo Reflective Sensor (Transmit – Receive)

Photo reflective sensor include both infrared transmitter and detector in one sensor. The photo reflective sensor emits a beam of infrared light  from its infrared transmitter. 

When an object is in the sensing area, the emitted light is reflected  back towards the photo detector (Darlington phototransistor). The amount of light energy reaching the detector increases and cause an increase in the current output from the photo detector

It has 4 pins: 2 for emitter and 2 for detector (check data sheet) arranged as follows:

• Upper left: diode’s anode
• Lower left: diode’s cathode
• Upper right: phototransistor’s collector
• Lower right: phototransistor’s emitter

Features

• Compact
• High performance
• High output
• Easy to mount on PCB
• Widely applicable

Applications

• Timing sensors
• Edge sensors
• Micro floppy disc drivers
• Level sensors of liquid