Found in a 1964 Electronic Design, this circuit makes use of FETs of the time. These transistors can be replaced by modern general-purpose types. The input resistance is 30 M.
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...