Found in a 1965 Electronic Design, this circuit makes it possible to select signals with an inverted phase using a relay and a unit gain stage.
Found in the 1974 Ferranti transistor manual, this circuit uses components from the time,...
This “zero crossing detector” was found in a manual of operational amplifiers from the 1980s....
This emitter-coupled transistor LC oscillator circuit was found in the May 1970 issue of Radio...