This circuit was found in a 1945 publication. The circuit was stated to be part of a walk talkie. Note that, as it is a portable assembly, it was powered by batteries. The jack was for microphone insertion.
The power of this converter is not the greatest, it can only supply small fluorescent lamps,...
This circuit is in the very datasheet of Texas Instruments that manufactures the component...
Found in a PE Hobbyst Handbook from 1991, this circuit uses a common photocell as a sensor. The...