Found in a documentation from the 90's, this circuit uses only one integrated circuit. The resistors in series with the LEDs depend on the power that can be between 5 and 12 V.
This circuit was obtained in an old American publication from 1974. The supply must be made with 5 V...
Currents of a few milliamps are enough to drive loads up to 500 mA with this circuit. The...
Published with a power amplifier in the January 1985 issue of Radio Electronics, this circuit...