This LED special effects circuit was found in the February 1992 Radio Electronics magazine. The circuit uses 4 LEDs and is controlled by R3.
This circuit, found in a 1958 magazine, is for reference only, since the components are not easy...
Found in Popular Electronics this circuit triggers an SCR and lights an LED when the location of...
This OF-1 LO oscillator was found in a 1980s American documentation. The transistor can be any...