This circuit was obtained in an old Elektor and can be adapted to use white power LEDs. The transistor must be equipped with a heat sink. The circuit has a battery charger.
Using the CA3140 in the figure we have a comparator that goes low in the window voltage space. The...
With this circuit it is possible to connect a comparator to a power stage via two wires. The...
This simple circuit was found in the May 1979 issue of Radio Electronics magazine. The circuit has the...