This circuit was found in an 80's Electronic Engineering. The circuit uses operatives of the time that are not common today. The power supply must be symmetrical.
This circuit maintains on a flashing LED at a frequency determined by the capacitor. The...
After starting, this circuit turns off the relay in a time that depends on the 4020 pulse-count. This...
This sophisticated circuit is from a 1975 documentation. The components are from the time and the...