This circuit shows how to simulate a high-performance diode with two diodes. The circuit is from a 1960s RCA documentation. Modern general-purpose transistors can be used.
This circuit produces the hum of a mosquito, scaring the female of the species that are the ones...
This circuit is from an American publication from 1974. The circuit can be designed with PNP BC558...
This circuit was found in the Spanish magazine No longer in existence, Mundo Electrónico, in a...