Found in a 90's EDN this circuit can be used as a shield. The transistor is a general-purpose type and the frequency of the emitted sound is determined by R1 / C1.
With the presented circuit it is possible to measure resistances of many megohms using a low...
Series and parallel regulator (CB8814E) The two voltage regulator configurations are combined in...
This circuit was found in the power semiconductor manual of the 1980s ON Semiconductor. The...