This power source was found in a 1969’ Electronics World. The version is too sophisticated by the current it supplies and can be implemented with modern transistors.
This circuit can be used in a signal level indicator with LEDs. The circuit is from an Electronics Now...
This circuit for analog video signals was found in a March 1988 Radio Electronics. The Maxim...
This circuit was obtained in a 1960 transistor manual from Sylvania. The circuit can be...