p.cousens wrote: > If it had two pins it would be called a photo diode... 2-pin phototransistors were more common than 3-pin in my experience. As example: http://sharp-world.com/products/device/ctlg/esite23/table/072.html Mike. -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.