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.
This useful instrument has dual function, operating both as signal injector and continuity tester. The...
This 3 A adjustable source uses the LM350 integrated circuit, which must have a good heat...
The transistor for this flashlight brightness control may be the BD135. The circuit is from 1978...