In this Instructable I will show you how to make a simple infra red (IR) detector. When your TV stops responding to the remote it is hard to tell if the TV is broken or the remote doesn't work. Whit this little pocket-sized gadget you will know. Spying has become more and more accessible to the average man. Whit this gadget you can check if someone has installed a night-vision camera in you room or office. First I am going to show you how to build it and then how to use it. If you are just interested how IR remote control works got to step 7.
http://www.instructables.com/id/IR-Detector/