This flasher circuit consists of an astable multivibrator with the frequencies given by the capacitors. The circuit is from 1965 using light bulbs, but LEDs can be used. Power comes from 4 batteries.
This 1964 Electronic Design circuit uses a photo-FET as a sensor. The component is rare today. |...
This two-input limit detector was found in an American 1980s documentation. The circuit can be...