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Article #196Re: Best way to power array of LEDs?
From: Andre
Date: Fri, 11 Oct 2002 14:21
Date: Fri, 11 Oct 2002 14:21
41 lines
3545 bytes
3545 bytes
"Michael A. Terrell" <terrell@mfi.net> 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 . -A
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X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: 112d1e,4ef4c9d4aea85e1f X-Google-Attributes: gid112d1e,public X-Google-Thread: 103407,4ef4c9d4aea85e1f X-Google-Attributes: gid103407,public X-Google-Thread: 1131b0,4ef4c9d4aea85e1f X-Google-Attributes: gid1131b0,public X-Google-Thread: 1118be,4ef4c9d4aea85e1f X-Google-Attributes: gid1118be,public X-Google-Thread: 10d137,4ef4c9d4aea85e1f X-Google-Attributes: gid10d137,public X-Google-ArrivalTime: 2002-10-11 07:21:26 PST Path: arc1-ca.pugleaf.net!archiver1.google.com!postnews1.google.com!not-for-mail From: testing_h@yahoo.com (Andre) Newsgroups: sci.electronics.components,sci.electronics.design,alt.engineering.electrical,aus.electronics,sci.electronics.repair Subject: Re: Best way to power array of LEDs? Date: 11 Oct 2002 07:21:26 -0700 Organization: http://groups.google.com/ Lines: 41 Message-ID: <2c2cf14c.0210110621.346ba78b@posting.google.com> References: <0001HW.B9C26E7400A7161B165FEAC0@news.covad.net> <3D9D3A1F.97DB97B4@prontoREMOVETHISmail.com> <slrnapvghj.hah.don@manx.misty.com> <3DA03315.9506C177@prontoREMOVETHISmail.com> <W8ao9.64063$Pz.71865@rwcrnsc51.ops.asp.att.net> <antapg$mu7t$1@hades.csu.net> <3DA319B9.76A904E6@mfi.net> NNTP-Posting-Host: 195.93.48.12 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8bit X-Trace: posting.google.com 1034346086 3027 127.0.0.1 (11 Oct 2002 14:21:26 GMT) X-Complaints-To: groups-abuse@google.com NNTP-Posting-Date: 11 Oct 2002 14:21:26 GMT