Found in a September 1992 Radio Electronics magazine article, this circuit generates a pulse as shown in the graph below the diagram. The timings can be changed by swapping C3 and C7.
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...