This circuit was originally intended for reading movie soundtracks. The circuit is from 1967 and was found in an English publication. The sensor is semiconductor type.
Using a voltage comparator, we find this AND gate on a Popular Electronics from the 90s. The...
We found this circuit in an old documentation from the 70s. Its purpose is to indicate the...
This circuit appeared in the June 1990 issue of Radio Electronics magazine. Integrated circuits must...