Introduction

The TCRT5000 are reflective sensors include an infrared emitter and phototransistor. There two tubes, the blue one is the emitter and the other is receiver, the emitter emit infrared and the receiver catch it when the infrared was reflected by the obstacle, and then the phototransistor is saturated, the module output high power lever, however, when there’s no obstacle to reflect the infrared, this module will output low power level.  

Technical Data

Operating wavelength: 950mm

Operate voltage: DC 3 to 5.5V

Typical voltage: 5V

Resource

wiki