This two-digit timer was found in the 1983 Special Projects issue of Radio Electronics magazine. The circuit uses components that can still be found today.
This power supply was found in the same 1990 special issue of Radio Electronics Experimenter...
This circuit, which can use a reed sensor, is indicated for doors and windows. The circuit was...
We found this circuit in a documentation from the 90's. Information on the A/D converter was not...