In a September 1992 Radio Electronics article, we found this basic 555 circuit used to generate fixed times. Capacitor C1 and resistor R1 determine the time. The circuit drives an LED.
This circuit was found in a 90s EDN. Its purpose is to increase the efficiency of operational...
This LED indicator circuit uses an LM339 comparator. The circuit was found in the January 1995...
This circuit was found in an 80's General Electric documentation. The circuit uses uncommon...