Found in a 1980s German publication, this circuit tests batteries by type. The circuit is based on a range of LEDs of different colors and is given a table with indications for various voltage ranges.
April 2017 - Mouser Electronics already has the MAX4007 from Maxim Integrated in its inventory, an...
This circuit was obtained from an English magazine from 1979, but can be easily assembled today...
Found in a 1978 publication, this circuit uses germanium transistors and drives a small 20 to 50...