We found this circuit in the October 1991 issue of Radio Electronics magazine. The circuit uses common components and can still be assembled easily today.
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,...