Found in an English publication from the 1980s, this circuit can be built with equivalent transistors such as the BC549. The signal must be applied to an external amplifier.
The configuration shown in the figure is one of the most traditional when it is desired to produce...
This burglar alarm is highly efficient, depending of course on the care with which it is...
This shunt voltage regulator was found in an Electronic Design from the 90's. The power transistor must...