Found in an Electronic Design from the 90's, this circuit measures the equivalent resistance in series of a resistor. The circuit operates at 50 kHz producing a rectangular signal.
This traditional configuration that any Series 139 comparator can use is found in the 1990...
The circuit shown in the figure can be used to detect vibrations or to provide amplified acoustic...
This toy organ was found in Popular Electronics from January 1967. It can be constructed from...