Re: Do LEDs become older after being used for 1 year?

From: Spehro Pefhany (speffSNIP_at_interlogDOTyou.knowwhat)
Date: 10/28/04 

Date: Thu, 28 Oct 2004 11:14:52 -0400

On 28 Oct 2004 06:50:40 -0700, the renowned iwicom@yahoo.com (Q Gang)
wrote:

Chin:-

Especially some cheaper white LEDs will lose brightness after a long
time operating near maximum current, but I don't think this is your
problem. (we call it "aging"-- of course they are a year older after a
year whether they are used or not. ;-) )

Zai jian.

>I found a strange things in my LEds device.
>
>I made a "Batterless Bicycle Safety Lights" 12 months ago.
>(http://www.freelights.co.uk).
>
>The LEDs on the device are opened to the air, sometime raining, water
>will touch the LEDs. Few days ago I found the red LEDs not working. I
>checked all system, nothings is broken. Then I uses a 3v battery to
>test the LEDs, the LEDs are working, but I feel the red LEDs are
>little darker than the new LEDs. When I put the red LEDs back to the
>device, the red LEDs still not working.
>
>Finally, I change the red LEDs (replaced by 2 new red LEDs), the
>system working again.
>
>The problem is: Will the LEDs become older after using a while? Such
>as become darker, resistence will go up.....
>
>Someone who are know LEDs well can give me a answer. Thanks very much.
>
>This is very important to me, because I plan to mass manufacturing
>this product in low cost. If the LEDs will become older, I have to
>change the designs for mass manufacturing. (To be honest, I do not
>know how the do the redesign job if the LEDs do get older).
>
>If you are interested see my redesign works for mass manufacturing, go
>to:
>http://www.helpyou.freewire.co.uk/redesign.html
>
>Thanks for your help.
>Chin

Best regards,
Spehro Pefhany 

-- 
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