We found this measurement circuit with a logarithmic scale in an Electronics Now from November 1995. The circuit uses an integrated component from that time.
This TTL dice was found in an old American 1980s documentation, but can still be easily assembled....
This circuit for several frequencies was obtained in an American documentation from the 90s. The...
November 2016 - Vishay's new proximity sensors VCNL4100 for display presence and activation,...