This circuit is from the 1983 Intersil Databook. The circuit has an A / D converter for display of 4 and a half digits being powered by a voltage of 9 V.
This circuit was originally intended for reading movie soundtracks. The circuit is from 1967 and...
This circuit was obtained in an old magazine from the 1970s. The circuit can still be assembled with...
This circuit recognizes a tone determined by the tuned input circuit (R3 / R4 / C2). The circuit...