Lightbulb Filament Replacement

[Gary H]

Most CFLs take less than a second to reach full brightness. IIRC, it's the floodlights that take too long.

[Sjouke Burry]

That no problem for you. You need BRIGHT ideas, only then will you need a pop-up lamp.

[willshak]

Like those mercury vapor lights. Ooops. Mercury!!!!! Heaven forbid. We're all gonna die.

[Don Klipstein]

I remember a study that Osram did on life cycle energy usage by incandescents, CFLs, and LED bulbs. In all three types, no more than about 2% of the total was for matters other than electricity consumed during operation, such as manufacturing and disposal.

Meanwhile, in my experience, CFLs have a high rate of lasting several times longer than incandescents do. So I don't see them being all that "non-green", especially considering how much less energy they use.

[Don Klipstein]

I think you got it right - in vacuum incandescents, they make the filament longer than if gas was used so that the filament would run cooler.

[Don Klipstein]

Most are indeed filled with a gas, usually an argon-nitrogen mixture, maybe 93% argon 7% nitrogen.

But if the ratio of power input to visibly apparent filament length (that is, before uncoiling it) is less than something like 20 watts per inch or so, then the bulb usually has a vacuum rather than gas. Only when the ratio of power to filament length is above somewhere around there does the benefit evaporation retardation of the gas (allowing higher filament temperature) outweigh the heat conduction loss caused by the gas.

One way to tell if a light bulb has a gas fill or a vacuum is to see if the top of the bulb gets very hot (that means gas). If you have a Tesla coil handy, it gets easy to tell - bulbs filled with the usual argon-nitrogen mixture will have pink streamers form in them (sometimes with violet areas at their ends) if they are brought close to a running Tesla coil. Vacuum ones generally refuse to glow, but could develop a somewhat uniform glow over their inner surfaces from extreme slight trace of some gas with enough voltage from a Tesla coil. (Don't do that for long - possible X-ray risk.)

I know this from experience.

[Don Klipstein]

The usual fridge and oven bulbs are among the many exceptions to the upcoming incandescent ban. Chances are, the other locations can use incandescents that are exceptions from the ban, especially if they can't use CFLs.

[Don Klipstein]

My experience is that most bare-bulb CFLs are at about 1/3 of full brightness when they start and actually get going, give-or-take depending mostly on temperature. And they get close to full brightness in half a minute to a minute.

And, that ones with outer bulbs around them start around or even under

1/10 of full brightness, and take 2, maybe 3 minutes to warm up. This does vary with the temperature that they have to warm up from.

[J Burns]

The temperature also depends on input power. The ambiguous area is between 6 and 10 watts per cm of filament.

Gas allows a filament to run hotter, which is more efficient. If you aren't going to run the filament that hot, vacuum is more efficient.

I have Westinghouse's Large Lamp Specification Guide from 1975. Most bulbs of 50 W and less were vacuum. 60 and 75W were a mix. Everything of 100W and up seemed to be gas.

[The Daring Dufas]

Are you trying to insult me?!! Keep trying, I had Irish nuns for teachers, nothing bothers me. 8-)

TDD

[Stormin Mormon]

Did you ever sneak in while they were sleeping, and play connect the dots on their faces?

[Sjouke Burry]

The thought never entered my mind. I'm innocent. Dont sent those nuns over please.

[Molly Brown]

Many people have outdoor flood light fixtures that have a cover on them. The cover is designed to keep the water from rain and sprinklers off the socket and base of the housing so it doesn=92t short or just plain rot. There is NO fluorescent flood bulb short enough that would fit in these outdoor fixtures due to the cover. What do you propose these people do?

[ransley]

I use the smaller size 15 watt and spiral cfls in them, the spiral are cheaper and light quicker. The larger 22 watt are to big

[Stormin Mormon]

Join the Mormons.

[jw]

Just thinking of the term "Vacuum Tube" like the old tv and radio tubes. I would assume they had a vacuum. They also had a filament similar to a light bulb, but lower voltage and they never clowed more than a dull orange. which would tell me that they are running at a low current draw. I recall testing them in the old days and there was a test for "Gassy". I believe that meant that air had leaked in, because I sure cant see how they could have gotten any actual gasses in them. I remember taking old tubes that were bad but still had a working filament and over voltaging the filament. It really did produce light for a short time. Like running 12V into a 6V tube. I also liked to watch the bluish glow in the old power tubes, like the finals in audio amplifiers. It moved to the music, which was actually the power loads inflicted on the tube by mostly the bass.

Sorry, if you're under 35 or 40, you probably have no clue what I'm talking about. :) It's just electronic history..... Google "Vacuum Tube". They were pretty neat things. I liked playing with the old tube stuff when I was a kid, even if I did get knocked on my ass a few times, because those circuits often had 300 to 1000 Volts DC, and that can knock you down real fast. And worse yet were those old TV CRTs that held a charge for hours after being turned off.

[jw]

Did you ever try to use a CFL bulb in an unheated out building in the winter? First you're freezing your ass off when you enter the garage, you flip the light switch and get less light than a common flashlight for the first minute or two. Eventually they get brighter a little at a time. But in the coldest months of the year they never reach full brightness. So, instead of running to the garage to get that 1/2" socket and getting back to the warm house in under a minute, you spend

5 minutes freezing your ass off before you can read the numbers on the socket.

In summer my garage and other out buildings have CFL bulbs, but in winter I put back the plain old incandescents.

Then too, in some situations, florescent bulbs are just plain ugly for their color. Too much blue and they make for bad photography and are depressing to be under for hours at a time.

I DO NOT agree with the "lasts longer" part. That's just an advertising gimmick. From personal experience, I find they last the same, or often less. The oldest ones that were straight seemed to last real long. These spiral ones just dont seem to last.

[jw]

You probably dont want to hear my proposal, but here it is: DONT VOTE DEMOCRAT DONT VOTE REPUBLICAN DO VOTE FOR ANYONE ELSE

There, I said it, and I'm sticking to it . . . . .

[ransley]

At 10f and below they take a long time to brighten, the floods take even longer, color wise you are using an outdated type or perhaps a off brand, try HD cfls their color is as good as incandesants. Life wise you are wrong and you get free replacements for 9 years at HD. You dont beleive me, there are 2 cfl reviews at Popular Mechanics magazine and Consumer Reports, the poor color issue was solved years ago with better Phospors, no blue, no depressing colors, but photographys issue wont ever go away and who cares, I save 75% on electricity get longer life and free bulbs when they fail.

[Jeff Thies]

Not all CFLs are equal. Except for the ones in Big Lots or the dollar store. Or any bulb with America or US in the name. Those are equal trash.

I haven't replaced a CFL in a couple years. Well, I did replace a friends yesterday, it was a "Lights of America" brand.

And, as far as photography, I've looked at a lot of photography, and done some under CFL photo lamps. Way better color than a hot lamp that last only hours. They make some big big photo CFL lamps.

It rarely gets into the teens here, but it did last winter, and I had no problem with my CFL porch lamp not putting out the full light. It is a name brand enclosed lamp, and those take longer to warm up. Or, you could use a CCFL (cold cathode), instant on at any temp but lower efficiency, still much better than incandescent. I'm using one right now in my laptop.

Jeff