Found in an old Popular Electronics, this circuit warns when a remote lighting system is not working. The circuit uses an LDR as a sensor and the components used are quite common today.
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...