This circuit turns off a load after an interval of 8 to 80 seconds adjusted on the potentiometer. The circuit is from a Radio Electronics June 1970. The time depends on C1 and can be changed.
For those who like experimental circuits, here is a sequential flasher system with LEDs, which can be...
This circuit was found in an ancient American documentation. The integrated circuit is of the time...
This circuit was found in a 1977 Radio Shack documentation. The circuit is tuned to 1.4 kHz, but...