Found in a radio amateur magazine of the 1980s, this circuit uses components that can still be found easily. The circuit is for NiCad batteries.
The LDO series (Low Dropout) TPS80 from Texas Instruments (www.ti.com) can provide output voltages...
The presented circuit uses an operational one of the time. The circuit is from an 80's manual and...
The operation of this circuit is old, but the configuration can be elaborated based on modern...