Horrendously complex MPPT solar panel controller.(Maximum Power Point Tracking) Enough related stuff to make it worth looking at. Uses a PIC :-) http://www.drgw.net/workshop/MPPT/mppt.html Russell -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist