This circuit that can be activated by light or heat was found in an old American documentation, but the components it uses are perfectly current. The power transistor shall be fitted with a heat sink.
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...