This Design Idea provides complete instructions for designing solar day lamps using both passive and active current limiting circuits.

[Carl] recently upgraded his home with a solar panel system. This system compliments the electricity he gets from the grid by filling up a battery bank using free (as in beer) energy from the sun. … ...

The solar day lamp is a very simple and cost effective way of utilizing solar energy. It consists of one or more solar photovoltaic (PV) panels connected to an array of LEDs. Because it has no ...

1. The solar day-lamp schematic shows two identical strings of LEDs, each fed by a basic current source using a current-defining resistor. The output of the PV panel is connected through a switch ...