This circuit was found in an Electronics World of 1968. The transistor can be any general purpose and the double T must be set to R3 for the desired effect.
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...