How do IR sensors detect obstacles?

                                        https://www.youtube.com/watch?v=J73JKVqQvpM

                        How do IR sensors detect obstacles?

    Introduction

    Infrared Obstacle Sensor Module has builtin IR transmitter and IR receiver
that sends out IR rays and appears for mirrored IR rays
to identify the  presence of any resistance in the front of the sensor module.
The sensor has very desirable and stable response even in ambient light
or in entire darkness.

    Specifications

Operating Voltage: 3.0V – 5.0V
Detection range: 2cm – 30cm (Adjustable using potentiometer)
Current Consumption:at 3.3V : ~23 mA,at 5.0V: ~43 mA
Active output level: Outputs Low logic level when obstacle is detected
On board Obstacle Detection LED indicator.

    Working Principle of IR Obstacle Sensor

    An IR sensor consists of an IR LED and an IR Photodiode; together they are known as  Photo–Coupler or Opto–Coupler. As stated before, the Infrared Obstacle Sensor has builtin IR transmitter and IR receiver. Infrared Transmitter is a light emitting diode (LED) which emits infrared radiations. Hence, they are known as IR LED’s. Even though an IR LED appears like a everyday LED, the radiation emitted by using it is invisible to the human eye. Infrared receivers are additionally known as  infrared sensors as they discover the radiation from an IR transmitter. IR receivers come in the shape of photodiodes and phototransistors. Infrared Photodiodes are distinct from regular photo diodes.

     Application:

1:Door opening and closing system
2:Auto click camera when object is in range
3:Shutdown motor when there is no (water) liquid flow
  to prevent damage of motor called dryrun
4:In decoration

Author: Prashant Agre
email: agre.prashant@gmail.com