Found in a 1969’s EDN, this circuit provides 4.5 V with a 100mA current for digital logic. The circuit uses transistors from the era.
Texas Instruments ESD122 Electrostatic Discharge Diodes (ESD) can be ordered from Mouser...
This circuit was suggested in a 1976 documentation. We can use the pair BD135 and BD136 on the...
This interesting circuit found in an Elektor from the 90s controls loads in four quadrants of the driving...