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 polarity test or indicator indicates the polarity of a power line by LEDs. The circuit is...
This is the circuit of a digital clock published in the January 1975 issue of Radio Electronics magazine....
Found in an Elektor from the 90s, this circuit can be powered directly by the power grid. The...