The core concept has stayed the same since the original version. He wanted a flashlight that was small and used no batteries. This iteration came about as he looked at increasing the light output of the device. He’s switched to some warm-white LEDs which are easier on the eyes, but was unhappy with the charge life now that he’s using current at a faster rate. The solution, of course, is more potential from the capacitor. He’s now using two 10 Farad caps in parallel. We are a little skeptical about his capacitor theory and ended up using this lecture to defog the issue of parallel and series capacitance.
The upgraded hardware is right at home in that plastic egg like you’d find in a coin-op trinket vending machine. You’ll see there’s still a colored LED to warn when the charge is getting too low.
Filed under: led hacks