Using a MAX644 this circuit was found in the April 1989 issue of Radio Electronics magazine. The circuit is for a 5 V voltage and 50 mA current output.
Here we show how two 4017s can be cascaded to count above 10. The circuits are driven by a square...
The circuit in the figure represents a typical application of a phototransistor exciting a relay...
This circuit, in fact, what it does is a reactivation of the batteries through a brief pulsating...