We spotted [Kerrin Mansfield]’s lovely solar engine on ladyada’s rantings. It uses 16 1/8th inch solar cells to collect power. At night, an orange LED pulses at .2Hz. He doesn’t have a specific write up on the construction, but from the component layout, it looks identical to [Gareth Branwyn]’s schematic in Make 08, which you can find in the PDF.