This solar cell is particularly good with the most powerful silicon we've tested yet, and it's matched with a PCB etched with a Miller Solarengine circuit on the back of the solar cell. Simply solder the components to the locations on the back, flip it over into the light, and watch it run!

The prototypes were green, but our limited run are with the black mask (yes, you can still see the text under the black).

The Miller Solarengine is pretty well described "Bicore Experimenter's PCB" series of circuits.