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 ...

This is the simple version of a white LED lamp that can be directly powered from mains. It can give ample light even for reading purpose. Capacitor Cx along with diodes D1 through D4 forms the AC step ...

This is a quite simple DC to AC inverter that provides 220VAC when a 12VDC power source is provided. It can be used to power very light loads like night lamps and cordless telephones, but can be ...