This benchtop power supply with various output voltages from 1.5 to 12 V was found in Radio Electronics magazine from August 1960. The circuit uses power transistors of the time.
This circuit uses an impact sensor transistor called Pitran rare today. The circuit is from 1969...
Originally, this circuit was created to monitor the liquid level in the reservoir of a car's...
This Japanese commercial medium and short-wave radio uses 7 transistors and tunes the range from...