This circuit is from an 80's Radio Electronics. The circuit has several output options for 50 mA currents with load indicator through LEDs.
Found in an American documentation from 1969, this circuit operates at a frequency determined by the...
This source, obtained in the 1982 SGS manual, has pre-regulation and provides a current according to...
This circuit was found in the December 1992 issue of Radio Electronics magazine. The current is a...