This timer has a divider programmed by BCD switches. The circuit is from a Radio Electronics magazine from February 1989.
The operating system used in this circuit of the 1994 Linear Applications Handbook by National...
This TTL circuit was found in an American documentation from the 80s. The components are common in the...
This circuit is from a 1998 Poptronics. The circuit triggers a buzzer after a certain time, waking...