This basic circuit was found in the March 1998 issue of Electronics Now magazine. The circuit is powered by 2V and uses a 28 MHz crystal or resonator.
This circuit came out in an English publication of 1976, but it can be easily assembled using...
When light fails to focus on the sensor, a common photo-transistor, the relay closes its contacts....
This traditional clock circuit with common CMOS components with discrete logic functions was found...