This low frequency oscillator circuit was found in an Electronic Design from the 90s. The transistors are common types, and the frequency is given by the crystal.
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...