This circuit was found in a 1965 General Electric manual. What it does is give a warning if you leave the vehicle with the headlights on or lights inside.
The CK722 transistor used in this circuit is one of the first commercial types in the world. The...
This automatic dimmer for incandescent lamps was found in a European publication from the 1980s. The...
This traditional doubler configuration with the 555 can be found in other articles on the author’s site....