Suggested by Siliconix in documentation from the 90s, this circuit can present gains of digitally selected by the input going from 1 to 1000. The circuit can be adapted to work as a shield.
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...