This circuit can be used to obtain a zener voltage from a common zener of another value, adjusting in a multimeter. The circuit is from an American documentation of the 1970s.
This receiver was found in old English documentation and any general purpose NPN transistor can be...
This simple alarm with integrated CMOS sounds a piezoelectric transducer when the sensor circuit...
This circuit was found in an Electronic Design from the 90s. Operational amplifiers admit modern...