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 uses an LDR as a sensor to trigger an LED indicator at a preset lighting level. The...
We found this circuit in an American publication from the 80's translated into Portuguese. The...
We found this circuit in an old French documentation from the 70s, but it can be assembled using...