Found in American documentation from the 1980s, this circuit can be designed with equivalent components. The microphone can be of the piezoelectric type.
More and more supercapacitors are being used as supplementary sources of energy in several...
Varactor diodes are our varicaps of today. This circuit for switching signals in an RF circuit was found...
In this circuit the output current is limited by R3. For a 300 mA current, R3 must have 12 Ω. For...