This is simple but powerful bass, treble, volume control is made by General Op-Amp IC LM741. The input voltage is 12V, but it will also work with 9V and 6V. This has inbuilt pre-amplifier also. Left ...

To sense animals moving I wanted to create a simple IR sensor that would trigger a monostable to generate a rather long pulse when an animal passed by. Further, while the animal remained in front of ...