This circuit was found in the March 1997 Electronics Now magazine. It uses a common analog indicator and the transistor is a general purpose one.
Found in an issue of Elektor magazine in the 90s, this battery tester is based on the LM3914. The...
I found this circuit in a July 1982 English magazine. The circuit is still viable by simply using...
This circuit is from a 1966 Motorola Field Effect Transistors Manual. The circuit makes use of...