1. Home
  2. General Electronics
  3. EternaLite

EternaLite

Last year I bought a fluorescent light light, some cheap crap made in China. I installed it on "Oct. 7, 03, David recall election day", was wat I wrote on it. It has a phtocell on it, that turns it off during daylight.

Last month it started getting dim, and it's been getting dimmer and erratic until this month, when it started to quit for a period of time.

I opened it up, and found that the end of the tube where the filament is started to melt the plastic and turned the plastic brosn along much of its 4 inch length. So it worked for about 8 months, which is not a whole lot longer than the 4 watt incandescent lamps that I had been using.

So last night while I was at Fry's I bought, for $5, a Feit EternaLite LED night light. It's got a lifetime guarantee. Whoop-dee-doo. The light output is less than the fluo or incandescent, but it seems to be adequate. I think it's a single white LED, but the case is sealed up with no screws to gain access. It has a photocell to turn it off during daylight. They claim less than 2 cents a month on the electric bill.

In a year or so, when it dies, I'll have to crack it open and see what died. My guess is the LED will gradually dim to uselessness. But then I guess it's not time for specualation, it's time for waiting.

-- @@F@r@o@m@@O@r@a@n@g@e@@C@o@u@n@t@y@,@@C@a@l@,@@w@h@e@r@e@@ ###Got a Question about ELECTRONICS? Check HERE First:###

formatting link
My email address is whitelisted. *All* email sent to it goes directly to the trash unless you add NOSPAM in the Subject: line with other stuff. alondra101 hotmail.com Don't be ripped off by the big book dealers. Go to the URL that will give you a choice and save you money(up to half).
formatting link
You'll be glad you did! Just when you thought you had all this figured out, the gov't changed it:
formatting link

Reply to
Watson A.Name - "Watt Sun, th
Loading thread data ...

It's interesting that everything that emitts visible light seems to destroy itself. The energies involved are just right to have nasty thermal or ionization effects. Long high-voltage neon lights seem to last the longest, maybe.

John

Reply to
John Larkin

was

time.

is

of

EternaLite

be

during

what

then

Whatever happened to the neon lamps with the screw-in base? They seemed to last a lot longer than the ones with wire leads. I'm talking about the neon lamps that had a standard size base and screwed into a regular light socket. Not a little candelabra or whatever they were called base. I think the added inside surface area of hte glass gave them a lot more area to coat with the metal from the electrodes, so it took a lot longer to dim because of the silvery coating.

RIght now, the maintenance guys are going around campus with a bucket full of ballasts and replacing them in the fluo lights that have gone out. There seem to be a lot of them, judging by the quantity of ballasts they deal with.

Reply to
Watson A.Name - "Watt Sun, th

I'm guessing that properly-built neons fail mainly by adsorption and sputtering capture of the gas by the metal electrodes. The long movie-marquee tubes had a lot of gas in storage and made a lot of total light at low current density, so seem to last. The screw-in neons had a lot of gas volume, too.

There's no reason ballasts couldn't last centuries, if they were made right.

What would be the longest-life electrically-powered light source? Maybe an RF-pumped gas globe? Or a hideously inefficient incandescent? LEDs run at very low current?

John

Reply to
John Larkin

I'd vote for RF pumping. Dunno what would happen to the phosphor coating after many years, but almost everything else has electrode emitters that wear away after a while.

Reply to
john KB5AG

on Friday 09 July 2004 05:49 pm, john KB5AG top-posted:

What about RF pumped xenon? Doesn't it emit pretty much white light? Then you don't need a phosphor.

Of course, the RF source will wear out. :-)

I was thinking EL, and STR ~10 yrs; we had an EL nite-lite, and there was a penny packed with it on the card-pack, saying, "We'll pay you for the electricity it uses!". I don't recall how long it lasted, but it was a very long time, to a kid. When it finally started to go bad, it hadn't dimmed, but got an irregular black spot in the middle that grew until the whole thing was black. Well, grey, but you get the point.

--
Cheers!
Rich
Reply to
Rich Grise

to

seemed

about

regular

a

formatting link

Reply to
Watson A.Name - "Watt Sun, th

I'd guess that a high-power, low-voltage tungsten filamant (ie, very fat tungsten wire) run at low voltage might take eons to evaporate. It looks like the Livermore bulb is running at low filament temperature.

Somebody mentioned ELs, but I understand that they degrade with half-lives of a few years. All my EL night-lights seem to. EL LCD backlights, probably higher power density than night lights, don't last long. Beckman once made a frequency counter with 7-seg EL display, and it was a mess after a couple of years.

John

Reply to
John Larkin

ElectronDepot website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.