Found in a documentation from the 70s, this circuit causes the courtesy light of the car to remain on for an additional time after the doors are closed. The time depends on C1.
This power supply, found in an Argentine publication from the 1970s, uses a wire potentiometer of 25 W or more...
This circuit was obtained from an English magazine from 1979, but can be easily assembled today...
The oscillator shown in the figure generates a 1 kHz tone that is reproduced on the speaker with...