What would you do if you came across a 100W, 7500 lumen LED diode for under $10? Probably something like this.
It’s actually quite amazing how cheap LEDs are getting. [Julian Ilett] found this 2″ x 2″ LED on eBay for only £4.79 (<$10 USD). It’s rated for 32-34V with a current draw of 3000mA, which works out to about 100W. Its brightness? 7500 lumens. That’s brighter than most home theater setups.
At that price, [Julian] had to try playing with one. The problem with these higher power LEDs is that they typically need a rather expensive LED driver, due to the less common voltages they operate at — and of course, the concern of over-driving them and burning them out. Not interested in finding a suitable driver, [Julian] decided to try something a bit less conventional — wiring a pair of 18V drill batteries in series.
Unfortunately, fully charged drill batteries tend to hover around 20V, not 18V, which when doubled is quite a bit over the recommended voltage range for the LED. The good news is that since the LED draws so much current, there’s a good chance the voltage will drop right down to the “sweet spot” for the LED. So like any good hacker, [Julian] decides to throw caution to the wind and just try it.
As luck would have it, it worked! He darn near fried his camera sensor looking at it though! Satisfied with his test he’s gone on to make the world’s cheapest — and perhaps ugliest — 100W LED flashlight.
And upgraded it since.
And if you don’t need that much brightness, you could always recycle your lithium batteries into some awesome PVC flashlights!
[via Hacked Gadgets]