| Five LEDs are connected to a 9V battery by means of two series resistors are all you need to build this nice-looking Christmas star. The cir...
All items tagged with DIY and Battery (3)
| It appears that Europe is way, way behind China when it comes to the production of batteries. Billions will have to be invested to keep up....
| Occasionally there is the need to charge a battery from a laptop, mobile phone or PMR handheld using an ordinary laboratory power supply. It...