[Dhananjay Gadre] happened across a useful little trick the other day. Take any old 1N4148 or 1N914 glass-package signal diode and wire it up right, and you’ve got yourself a nifty little IR detector.

A diode is an electric device which allows the flow of current only in one direction and restricts the current flow in the opposite direction. A diode starts its operations when a voltage signal is ...