This 90s Motorola circuit from, has current limiting foldback. The power transistor is from the era, and equivalents can be used. The output is 250 V.
Ordinary batteries cannot be recharged, but they can go through a process of "rejuvenation" that...
We found this basic circuit of a relaxation oscillator with unijunction transistor in a 1976...
This circuit, from a 2006 documentation, automatically controls the activation of a water pump, and...