OT: LED Failure Poll

I'm not familiar with a LED Mag but every light that I have looked at

- quite a few as I use them for bicycle lamps - two things seem to be universal. (1) the output (1 watt, 2 watt, etc) marked on the case has no relationship to actual output and (2) the actual power, referencing the LED, not the marking on the case, is always very conservative. However, I think that this is not so much a matter of the LED but on the relative ease of fitting batteries. i.e., how can we fit the batteries in the case.

In bulk LEDs are cheap and I suspect that the cost difference between fitting 1,2,or 3 watt LEDs is insignificant in reference to the retail price of the light. I see 1 watt White LEDs quoted for $0.30 each, for example, and it is very likely that a negotiated price would be substantially cheaper.

Of course, heat is the enemy of a LED but normally flashlight LEDs consist of the LED fitted to a circular aluminum heat sink which should suffice. I have never actually tested 3 watt LEDs using only the supplied heat sink but I have fitted them to reading lamps and drove them with a 2.75 watt constant current driver and they didn't get hot and they lasted at least two years. I can't say how much longer they might have lasted as I sold the boat.

-- John B.

You're welcome. I bought four of them to put some 12V emergency lights in the house. If I like them, I'll buy more to put in the shops.

Not in personal equipment, but I notice that some of the LED traffic lights have missing "pixels", so those must be LEDs that quit.

RWL

Plus the fact that they get plugged up with snow. Gerry :-)} London, Canada

WHich is really a meaningless observation, as you well know. Depending on the other factors involved. A 27 W lamp could be drawing .01 A, or 100A depending on the voltage, or a 1/8 W resistor could easily handle 100A at that rating or .001A all depending on its resistance.

But on the other hand CRAP is CRAP, true enough.

jk

Gunner Asch on Sun, 06 Nov 2011 09:24:24 -0800 typed in rec.crafts.metalworking the following:

Up north, they have this small problem that they do not produce enough heat to keep themselves snow and ice free. At least you don't have to worry about icicles hanging from the stop lights.

tschus pyotr

Oh yeah - I'd sit down and do the math with the voltage and wattage and resistance/capacitance ratings on those components - but they're blown to heck already, so you can't read it.

And the factory in Nankang isn't going to share the wiring diagrams and parts pick lists and layout diagrams with you or me - you're probably a competitor looking to copy their crap even cheaper. This is why they came up with Un-marked discrete components and proprietary User Part Numbers for the IC's - to make it harder to reverse engineer things.

Suffice it to say the components usually don't blow up if the circuits hadn't been "Muntzed" (over-simplified - Google it...) and weren't being overdriven or over-voltaged in the first place.

Hint:

I may not be an electronics engineer, figuring out the block diagrams and finding all the blowed up parts and changing them is about my limit. But I can see it when they do it - they tend to leave the same circuit board design and component location masks with a lot of vacant holes. "We don't need any over-voltage protection there, eliminate those four MOV's on the power lines, and the three on the Input leads..."

-->--

Who is it that chooses to live in the bloody ARCTIC with storms so bad they blow snow horizontally and vertically, hmmm?

We don't have any lights clogging with snow here in southern OR. I wonder if there's any connection...

-- One word frees us of all the weight and pain of life: That word is love. -- Sophocles

"Gunner Asch" wrote

You better stay out of the whole East and Midwest then:

jsw In NH, where we deal with it, though not always happily. They restored power after a week and my phone wire is still down.

Yeah, I leave the midwestern, southern, northern, and eastern states alone. I'll occasionally visit and see the sights, but I sure as hell don't want to live there. Y'all can have 'em with my blessings.

-- One word frees us of all the weight and pain of life: That word is love. -- Sophocles

I bought them for emergency lighting in the hallways & bathroom which have no windows. I have gone up to six weeks without electricity after a hurricane and they should provide enough light for the intended application. There are 12V 48 LED modules on Ebay, if you want more light.

I have one of those. it's great for working in a tight space where a halogen light would burn you becasue you keep bumping the light.

I have several of those, in a couple different wattages.

I have a couple 12V jump packs with 18 AH gel cells to power them.