IR Proximity Sensor Module

IR Proximity Sensor module uses infrared rays to detect obstacles in the range of 2-10 CM. It has 3 pins i.e., Vcc, GND and Out. Operating current of this module is 5V DC hence 5V is supplied to the Vcc. GND is connected to the ground of the system. Out pin gives an active high output when any obstacle is detected. A potentiometer is also there in the module to adjust the detection distance.

The major components of the circuit of this module are the IR transmitter and receiver, Op-Amp, Variable resistor and output LED. IR LED is used as an IR transmitter that transmits IR light of wavelength 700nm to 1mm. A photodiode is used as an IR detector to detect the IR light which comes back after striking the obstacle. When IR light strikes, photodiodes start conducting current in reverse bias. An Op-Amp is used as a voltage comparator in the circuit. When Photodiode’s series resistor voltage drop is greater than the threshold voltage Op-Amp output is high otherwise its output is low. A variable resistor is to adjust the distance range of the module. Output LED turns ON whenever any obstacle is detected in the range of the module while it remains OFF otherwise. It is usually used in safety devices or devices which are used to detect obstacles.