There’s a spy movie – probably from the [James Bond] franchise – in which our hero is staying in a fancy hotel. It’s crawling with enemies, naturally, and eager to see if one has been snooping in his ...

The circuit presented here is a very simple and yet highly effective alarm system for protecting an object. The circuit requires no special devices and can be built using components that you will no ...

This simple alarm circuit was designed for use in a combined garage and rumpus room. It can be assembled on Veroboard and uses just one IC plus a handful of cheap components. The circuit is based on a ...