Found in a 1980s manufacturer documentation, this circuit can be used as an optical shield. The integrated circuit is from the era and modern equivalents can be tried out.
This watt meter was found in an old telecommunications documentation. The circuit is interspersed...
We found this circuit in the April 1992 issue of Radio Electronics magazine. The circuit uses an...
This circuit is from old documentation. The operational amplifier is uncommon nowadays. The...