This circuit was found in an English magazine from 1977. Signal inputs and outputs must be shielded, and the circuit can be powered by battery, since its consumption is low.
This amplifier was taken from documentation from the 1960s. Transistors are germanium types from...
This circuit was found in a 1980s document. The integrated circuit is from the time and the power...
In the figure we show a means of changing the output voltage of a fixed regulator, such as 7805 or...