This circuit that can be activated by light or heat was found in an old American documentation, but the components it uses are perfectly current. The power transistor shall be fitted with a heat sink.
This is a circuit that we use very often in our projects, and it also appears in many technical...
Found in an American paper from the 90's, this circuit can be adjusted to pass frequencies above 30 to 300...
This preamplifier is indicated for low and high-impedance sources as microphones, transducers,...