LED Failure
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LukeA
Flashlight Enthusiast
Reverse battery polarity.
EDIT: I should clarify, reverse polarity doesn't typically damage the LED itself (which, still functioning as a diode, blocks current with reverse polarity), but most driver boards release the dreaded magic smoke when power is applied to them backwards.
EDIT: I should clarify, reverse polarity doesn't typically damage the LED itself (which, still functioning as a diode, blocks current with reverse polarity), but most driver boards release the dreaded magic smoke when power is applied to them backwards.
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Rossymeister
Enlightened
-Reverse Polarity
-Overdriving With Too High Of A Current
-Chip Weevils
-Overheating
-Accidentally Touching The Dome Of The LED
Thats all that i can think of at the moment
-Overdriving With Too High Of A Current
-Chip Weevils
-Overheating
-Accidentally Touching The Dome Of The LED
Thats all that i can think of at the moment
LukeA
Flashlight Enthusiast
Mechanical reverse polarity protection involves a nub on either side of the positive contact on the bottom of the board to prevent the cell's flat bottom from making contact. Beautifully simple. Other boards have diodes on them, but this can be wasteful of battery capacity.
Rossymeister
Enlightened
Some Do, But Most Of The Cheaper Ones Do Not
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Rossymeister
Enlightened
Smoke would be bad.
Only A Light That Uses The Direct Drive Technique Would Be Damaged
Hitthespot
Flashlight Enthusiast
LEDs are very solid along with the respective Printed Circuit Boards they're attached to. And most of us would agree, "we're sold on them and we Love them too." The only down fall at present ( beyond the physical limitations mentioned above) is their varying degrees of tint, even among the same bin. Also the strong degree of Blue wavelengths of light and the weak wavelenghts of Reds. In many situations LED's will not provide the color accuracy or depth of field a equal lumen bulb will, and in outdoor situations some still prefer the bulb.
Welcome to CPF. As you read the posts you will learn the differences between the different LED's, HID's, Bulbs, etc.... ENJOY
Bill
LukeA
Flashlight Enthusiast
No, only a light that uses a driver without reverse polarity protection will be damaged. Reverse polarity won't do anything to a direct drive light.
PlayboyJoeShmoe
Flashaholic
In some VERY cheap multi LED lights often some of the LEDs will go out because they are directly driven pretty hard.
Other than that I had one DX LED drop in for the P60 capable lights fail. Don't know if driver or LED itself. But again this was a cheap thing.
Buy quality stuff like Garrity 9LED 3AAA in cheapish, or Inova or Fenix in better stuff and you'll be fine!
Other than that I had one DX LED drop in for the P60 capable lights fail. Don't know if driver or LED itself. But again this was a cheap thing.
Buy quality stuff like Garrity 9LED 3AAA in cheapish, or Inova or Fenix in better stuff and you'll be fine!
Rossymeister
Enlightened
LukeA
Flashlight Enthusiast
It depends on the number of cells. Cree specifies a maximum reverse voltage of 5V.
kirby
Newly Enlightened
What can happen if the dome is touched?
We have touched the dome of a P7 quite a few times and it seems to work fine still.
We took the Bezel or head out because we want 180 degree of spill at that time.
LukeA
Flashlight Enthusiast
What can happen if the dome is touched?
We have touched the dome of a P7 quite a few times and it seems to work fine still.
Damaging the dome is the problem, but you still don't want oils from your fingers interfering with the light output. That's fairly small potatoes though.
kirby
Newly Enlightened
Oh OK. Will avoid touching it again.
It felt almost like silicon when touch.
It felt almost like silicon when touch.
The HDS lights have reverse polarity protection without the diode drop penalty.
Rossymeister
Enlightened
Chip weevils?! you must be joking, right?
Please tell me that you're joking!
I believe "DM51" knows more on this subject than i do
Yoda4561
Flashlight Enthusiast
That's because it is
Older luxeon I/III/V leds had solid epoxy domes, generally not easy to damage by touching or cleaning off with a cloth. The new ones use optical grade high temp silicone. This is better for the LED electronics because it puts less thermal stress on the connections, but it's much easier to damage or knock the dome off by physical contact. Shock shouldn't be a problem though.
