How to make a cheap Night vision light for robots and other purposes
Today @ NRO we are going to dig into technology that can be a better and cheap alternative for night vision.
Unfortunately, true night vision in even the lowest quality can cost thousands of rupees just for the optic alone, excluding hardware necessary to mount the optic to a helmet or air soft rifle. It’s an expensive technology.
Even built of a simple night vision lamp can cost above few thousands rupees, as the technology used are too expensive. One of main technology for night vision is PIR sensors. Those greenish pictures we see in the movies and on TV come from night vision goggles (NVGs) or other devices that use the same core technologies. NVGs or Passive infrared sensors (PIR) take in small amounts of visible light, magnify it greatly, and project that on a display. But as they are dependent on light to see, so they are fail in complete dark backgrounds. Another thing is as a living being we all produce some contrast in environment, so they are again a fail with low contrast bodies.
However, there are alternative methods for seeing in the dark. There are several versions of educational night vision viewers and toy spy binoculars available on the market.
Achieving night vision within low cost is not that easy task, all thanks to IR. Simple IR LED can also be a boon if the expensively embedded technology like thermal imaging or PIR sensors stops working in expensive robots. And well known they are cheap too.
As light coming from IR LEDs are above human seeing frequency, so they can be used for spying purposes also. As an example if a robot having IR LED mounted on it, than its camera can see in that light but human being spied can’t see those lights. It makes IR LED more useful. (If you are testing a implementation of IR LEDs then see them glowing with camera, as they are not visible with bare eyes).
An example of circuit to implement IR LEDs with camera is shown in figure 1.2
Hope this helps you to create something interesting and new. Good luck to you!
The Author- Akhilesh Sharma is Technical Innovation Head at Graphic Era University, Dehradun-Uttarakhand India. After been indulge in several Tech innovation seminars now he is up for writing with “nextrollout.com”