Have you seen Infrared rays so far? It is difficult to see because it is beyond the spectral response of our eye. Our photosensitive cells in the retina detect only the visible light in the range 450-750 nm. But many animals can see infrared spectrum lying above 900nm.Then what we can do to check whether, the Infrared LED in our project is working or not. A Digital camera can solve the problem. See how it detects the infrared.
Power the Infrared LED and focus the lens of the Digital Camera or Mobile Phone camera exactly toward the front part of the IR LED. You can see the Pink coloured light from the IR LED which is the Infrared ray. Pulsed IR Rays from TV Remote will appear as blinking light. You can make a video of the same to see how the pulsations vary when each button of the remote pressed.
IR LED Off
IR LED On
IR LED with Filter (Grey coloured ). See the Beam is focused and narrow
TV Remote Off
Pulsed IR Rays from TV Remote
Filed Under: Electronic Projects