Found in an 80's Hands On Electronics, this circuit turns on a light when it gets dark and goes out when it gets dark. The circuit can be adapted to use high-brightness white LEDs.
Found in a Radio Electronics from the 90s, this circuit generates a 1 kHz signal to serve as a...
This low noise circuit was obtained from a 1980s US RF publication. Transistors used are uncommon...
This circuit applies to other operational ones, other than the one indicated. The formulas next to the...