This video explains the working principle of an IR sensor and its applications. You can build your own IR Sensor with the help of circuit diagram shown in this video.

An IR Sensor is an electronic device which senses certain characteristics of its surrounding by either emitting and/or detecting infrared radiations. A PIR Sensor is the one which works by detecting the heat or IR radiations emitted by objects. IR Sensor has an IR LED as a transmitter and a photodiode as a detector. It can be used for many applications depending on the requirements.

To buy IR Sensors: https://goo.gl/XFU1Pz

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