This circuit with a dual power supply generates sinusoidal, triangular and rectangular signals. We found it in the magazine Electronics Now of January 1996. The frequency goes up to a few megahertz.
We found this circuit that warns when the gate of a house is opened in an old documentation,...
With 3 transistors, we found this receiver in a documentation from 1966. The circuit has an output...
Generating a square signal (50% active cycle), this circuit was found in Siliconix documentation from...