We found this circuit in a Radio Electronics issue from July 1969. The lamp remains on until C1 opens. The time is given by capacitor C1.
This sophisticated alarm with traditional components was found in an ancient American...
This circuit is from a Fairchild digital clock module shown in the March 1977 issue of Radio...
This circuit was obtained in a Radio Shack documentation from 1977. It can be used as a multimedia...