Suggested by an American publication, this circuit has 5 operating conditions indicated in the diagram. The circuit can be designed based on modern equivalent transistors.
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...