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 circuit mimics the sound of a siren when we turn the axis of the small DC motor. The...
This sophisticated RPM counter circuit with discrete integrated circuits was obtained in a 1993...
This circuit uses complementary transistors and was found in Mullard's transistor application...