We found this micro amplifier in a technical documentation from National Semiconductor. The circuit can be used on an experimental phone, being powered even by alternative power sources.
Found in Popular Electronics from the 90's, this circuit makes use of components from the time. |...
This circuit for the logic control of the 555 in a power supply was found in the October 1989...
In this circuit, a light-sensitive SCR or Light Activated SCR determines the operation of an...