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.
This circuit is recommended for alarm systems since it has a good output stage. The circuit is...
) Suggested by Philips in a 1968 documentation this circuit has very high 10 ohm on-load voltage...
No information is given about the transformers in this circuit suggested by Motorola in a 1968...