Isonno writes, “One of the hit discoveries of Hacker Camp 5 were these little USB lights. Plugs in either way, and you turn on/off/dim by touching the back. Turns out the show is run by a chip called the Sigma SGL8022W. The datasheet has the schematic.”
Via the forum.
I also bought a couple of those here:
http://www.banggood.com/1W-50LM-Mini-Touch-Switch-USB-Mobile-Power-Camping-LED-Light-Lamp-p-956706.html
$1.79, free shipping, select warm or cold white.
If you get skin oil on the USB lights, won’t it cook the semiconductor?