Found in a 1960s RCA manual, this circuit uses components from the era. For the indicated circuit R1 is 28ohm and R2 is 1 k.
The circuit shown is from the 1994 Linear Applications Handbook by National Semiconductor. More...
This power supply that can supply current according to the LEC is suitable for small projects. The LED...
This circuit was obtained from the September 1977 issue of Radio Electronics magazine. The circuit is...