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From: email@example.com (Andre)
Subject: Re: Best way to power array of LEDs?
Date: 11 Oct 2002 07:21:26 -0700
References: <0001HW.B9C26E7400A7161B165FEAC0@news.covad.net> <3D9D3A1F.97DB97B4@prontoREMOVETHISmail.com> <3DA03315.9506C177@prontoREMOVETHISmail.com> <3DA319B9.76A904E6@mfi.net>
NNTP-Posting-Date: 11 Oct 2002 14:21:26 GMT
"Michael A. Terrell" wrote in message news:<3DA319B9.76A904E6@mfi.net>...
> Lizard Blizzard wrote:
> > James Sweet wrote:
> > > The traffic light LED's use a transformerless power supply usually so they
> > > flicker at 60 Hz, the yellow doesn't flicker because it's incandescent,
> > > they're on so little that the savings of using LED's for them would be
> > > minimal.
> > Around the city, I've noticed thast even the yellow stop lights are
> > LEDs. I believe the reason was that if the yellow lamps were left
> > incandescent, then the system would still have to use AC line voltage.
> > I think one thing was contemplated when they converted to LEDs, the use
> > of lower power and voltage would allow the whole traffic light system
> > run off backup batteries. This was important in the last year or so
> > because of the possibility of rolling blackouts in (So.) California.
> > --
> > ----------------(from OED Mini-Dictionary)-----------------
> > PUNCTUATION - Apostrophe
> > Incorrect uses: (i) the apostrophe must not be used with a plural
> > where there is no possessive sense, as in ~tea's are served here~;
> > (ii) there is no such word as ~her's, our's, their's, your's~.
> > Confusions: it's = it is or it has (not 'belonging to it'); correct
> > uses are ~it's here~ (= it is here); ~it's gone~ (= it has gone);
> > but ~the dog wagged its tail~ (no apostrophe).
> > ----------------(For the Apostrophe challenged)----------------
> > From a fully deputized officer of the Apostrophe Police!
> Here in Central Florida I see them replacing the red lights with LED
> assemblies, but not the yellow or green. I have noticed a few already
> have a couple bad LEDs and haven't been in use for a full year.
Probably damaged during assembly . I'd bet that if you pressed on the
LED it would come back on .
The cause is ball bond failure due to overheating , possibly due to
soldering at too high a temperature or damage when stress testing .
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