This negative voltage source was found in a Popular Electronics from the 90's. The transformer has 120V secondary and 4-12V primary.
This simple regulated power supply was found in a 1977 documentation. The zener diode determines the...
This circuit was obtained in a 1977 Radio Handbook. The transistor is from the era and the coils...
This circuit uses matched transistors. The circuit is from Electronics Now magazine and has a...