On 22 Dec 2005 09:12:15 -0800, distar97 wrote:
I recently got an inexpensive HK keychain light with a UV led. It
worked great at first. After a very short amount of time, the
brightness dimmed to a useless level.

Thinking it had cheap 2016 (2) cells to begin with, I replaced them. No
effect. Then I noticed there is no current resistor or even space for
one. The led leads are simply placed above and below the 2 cell stack,
finger pressure makes the contact. So the 2 cells (6Volts) go directly
to the led leads. Does this sound right? Not to me.

If LEDs are not current limited, then what you have observed is execatly
the End Result. It's all Made In China crap now-a-day -- so I would
question the 'design' behind it. Maybe, just maybe, it was designed to
'ruin' the LED at about the same time the 'non-replaceable' battery
died. Their junk - our landfills.

I remember reading about reliability problems with UV leds. Is that
still the case?

Separate topic, I guess? Duuno 'bout UV LEDs -- even if they exist.
(It's only been recently that blue LEDs have reached The Masses.)

Jonesy
--
Marvin L Jones | jonz | W3DHJ | linux
Pueblo, Colorado | @ config.com | Jonesy | OS/2
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