This circuit for cars of the time was found in a Popular Electronics magazine from the 90s. The circuit is based on CMOS logic that is common even today.
Found in Radio Electronics from the 90's, this circuit employs a 3140 operational amplifier, still...
This simple logic probe circuit was found in the August 1980 issue of Radio Electronics magazine. The...
This is one of many versions of this circuit that the reader can find in this section. The circuit...