We found this circuit in a 1965 Electronic Design. Transistors are still common but admit equivalents for some of them. The circuit drains a current of only 4 mA.
This simple low-current charger does not use a transformer, having been found in a 2001...
This circuit produces a good power audio signal, whose frequency is controlled in the...
This circuit provides an output voltage when the input voltage is in the range between V1 and V2...