This circuit is from 1994, from a technical documentation from National Semiconductor, but can be adapted to work with more modern components.
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...