This circuit was found in the April 1971 Radio Electronics magazine. It uses common transistors and can be adapted to use an LED or audible indicator instead of a light bulb.
This circuit was obtained in a 90s American documentation. The integrated circuit used is uncommon...
This circuit was obtained in a 1980 English magazine, but it can be easily assembled today, since...
This configuration is used to display the characteristic curve of a diode in the virtual...