These 6 to 12 V source with current up to 100 mA was found in Radio Electronics magazine from June 19666. The source has a current indicator and uses transistors of the time.
This circuit was found in a 1964 documentation. It shows how to achieve automatic gain control for...
Using transistors at the time, this circuit was found in a 1967 Ferranti documentation. The...
This circuit, which controls both the temperature and the level of a liquid in a reservoir, was...