Hand powered smartphone charger updated

Back in October 2010 Ben Heckendorn discovered that a hand-cranked LED flashlight had enough juice to recharge his smartphone. He recently revisited this idea on his show and updated the hack by adding a simple voltage regulating circuit using a Zener diode and a 100hm resister. He also added a USB port to plug in a microUSB recharging cable. (via electronista)

Hand powered smartphone charger from an LED flashlight