This circuit is from the 80's documentation. The integrated circuit is from the time but can be implemented with modern equivalents. The power supply must be symmetrical.
This circuit emits a sound when a magnetic field, of a magnet, for example, approaches the sensor....
The circuit shown here uses a flip-flop found inside the 4048 to divide the original frequency...
This two-transistor amplifier stage has a feedback network allowing a voltage gain between 10 and...