When working around mains voltages, it can be useful to know whether a given circuit is live or not. While this can be done by direct connection with a multimeter, non-contact methods are available ...

Discover how to build a simple wireless power transfer system at home using readily available components like enameled copper wire, an LED, a 2N2222A transistor, and a 9V battery. This step-by-step ...

Since I’m starting to use more 9V rechargeable batteries, I thought it would be a good idea to build a simple 9V rechargeable battery for my friendly guitarist instead of having to urge him to look ...

Although the modular Portable Mixer design available on these web pages has become a hit for many amateurs, some correspondents required a much simpler device, mainly for mixing mono signals. This ...