This digital circuit is from a Radio Electronics magazine from December 1991. It does not use a microcontroller, but rather discrete digital circuits of the time.
The normal use of a 4520 as a divide-by-16 counter is shown in Figure bellow. In the normal...
This 1 MHz oscillator was found in the February 1992 issue of Radio Electronics magazine. The...
This circuit was obtained in a Popular Electronics of the 90s. It warns when the indicator lamp is...