What happens if you highly overdrive LEDs?

KingGlamis

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I just noticed that the LED insert for D-Mags is the same size as the bulb for my 18V DeWalt work light. So what would happen if I put 18V to a LED designed for 9V max (6D Mag)? Is there any danger to trying this? Or will it just instaflash and not work anymore?
 
It will be very bright for a second or so, then the light will turn blue and the emitter will start to smoke. Then it might explode, but I have never let it get that far. Yet.
 
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Well... it has been running at 18V for three minutes now. Still working. I will post a review and pics once my test is done.
 
It's still going. The beam is really weird. Kind of bright but with lots of odd rings. This is with a Nite Ize LED emmiter for Mag 2-6 cell lights. Since the 18V battery hasn't blown up the LED yet my guess is this thing would run for weeks on a battery this big.

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It's a little brighter with the freshly charged battery, but still no problems. I'm basically running this LED at twice it's rated voltage with no problems. But yet I don't see twice the light output. Not even close. Hmmmmm. I love experimenting, it's fun.
 
So it has been going for over a half hour on double the normal voltage, and still going strong. Hmmmm... food for thought. And I will be the first to admit this is not the best host for beam shots, but the voltage thing has me curious.
 
It's a little brighter with the freshly charged battery, but still no problems. I'm basically running this LED at twice it's rated voltage with no problems. But yet I don't see twice the light output. Not even close. Hmmmmm. I love experimenting, it's fun.
To be fair, the LED module has a regulation circuit that makes sure the LED gets a certain current, to a degree, regardless of input current. That circuit was probably designed for up to 9V, several Ah. The 18V NiMH DeWalt pack supplies probably about 2.5Ah. It may be within the circuit's design specs, but it's still impressive that the circuitry is robust and versatile enough to handle such a wide range of currents.
 
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Here is a comparison of the same exact DeWalt lights, with Nite Ize LED on the left, and the stock DeWalt Incan light on the right. The Incan clearly kicks ***.

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The Nite-Ize LED module contains a buck-boost regulator designed for an input range of 2V(completely dead pair of alkaline batteries) to 9V(six brand-new alkaline batteries). I would suspect that the Nite-Ize people have used devices rated for a higher voltage than they really needed. I seem to recall an electrolytic cap on this thing... that should be the first thing to blow if you overvolt it too much.
 
Try doing the same thing with a bare LED and report back... (oh and open a window before doing it).
 
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