This charger for automotive use provides a 0.42 A output current. We find it in an American documentation from the 90's. The transistor must have a heat sink.
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...