How do an IR transmitter and receiver work?-（2）

拙b

An IR Transmitter or an Emitter in general terms is an IR LED usually emitting light of around 760 nm wavelength and made up of GaAs (Gallium Arsenide) and a Receiver or a detector is generally a photo diode.






Now these are generally used for object detection ( Proximity Sensors) and can be connected as:



with
Transmitter (IR LED): Forward Biased (Anode (Longer Terminal to Positive))
Receiver (Photo Diode): Reverse Biased (Cathode (Shorter Terminal to Positive))

Output can be taken from the Longer Terminal (Anode) of the photo diode and given to your applicable device.