This circuit was found in a 80s American documentation. The zener diodes determine the points of action of each stage and the transistors can be general purpose types.
This fiber optic receiver was obtained from a 1978 documentation. We can use any modern...
This circuit was found in a Popular Electronics documentation from the 90s. It is possible to switch...
This circuit was found in an old Motorola documentation from the 70s, as it uses one of its...