Linked sites are likely to get updates before I next note them. Dc circuit book pdf: This site describes open source hardware and has open source software. You may want to come back here every few months.
The most efficient LEDs and where to get them! Also info on neon, low pressure sodium, oddballs such as green neon lamps. Also better info on lamps for growing plants. 60-800 mW red lasers would be! Also stuff on He-Ne lasers and more. 35-plus meg of good stuff, plus over 350 GIFs and JPEGs as of V. Don’s Xenon Flash and Strobe Page!