If you’re going camping this summer, or just want a cheap emergency lantern powered by a pair of AA batteries, you probably can’t do much better than [rimstar]’s Joule thief compact florescent lantern ...

In the April 4, 2024, issue of EDN, the design of a solar mains hybrid lamp (HL) was featured. The lamp receives power from both a solar panel and a mains power supply to turn on an array of LED lamps ...

Batteries. Batteries. Batteries. The average U.S. household has at least 28 battery powered devices. The problem becomes how to replace those unique, hard-to-find batteries? Area residents now have a ...

Here is a crude but efficient tricky charger for Lead Acid Battery. It uses a 12 volt car bulb as current regulator and charge status indicator. The brightness of the bulb indicates how much charge is ...