This receiver uses old transistors that are equivalent to BC548 and BC558. The photo diode is of any type. The receiver can be used on a highly sensitive audio link.
This circuit with 1W of output was found in a Mullard manual from 1960. The consumption is low and...
This circuit was found in an old documentation. It converts DC voltages and its maximum current...
In the figure we have the way to implement a 5 to 45 V zener diode with 50 mA of maximum current...