In this charger the current is limited by the incandescent lamp. Lamps from 40 to 100 W can be used and even connected in parallel, depending on the load.
This circuit was obtained from an Electronics World of 1969. General-purpose transistors can be...
This simple circuit supplies a constant current to an LED from supplies that can vary between 6...
In the figure we have a voltage regulator circuit for a source with protection. It was published in...