This 1V heater tube circuit was found on a Radio Craft from 1945. The circuit is for medium wave and can be used as a tuner.
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...