This circuit that can be activated by light or heat was found in an old American documentation, but the components it uses are perfectly current. The power transistor shall be fitted with a heat sink.
This circuit is from a 1968 Electronic Design. The components are from the era and the operating...
In this charger the current is limited by the incandescent lamp. Lamps from 40 to 100 W can be...
This circuit was presented in a January 1990 Radio Electronics magazine article as part of a home...