Replacement bulb for constant on off cycles

Gunner Asch on Tue, 07 Jan 2014 21:36:38 -0800 typed in rec.crafts.metalworking the following:

Just picked up a case of 60watters - 120 bulbs for 19.80 less a geezer discount. Now where the bleep I'm going to store these ... B-)

-- pyotr filipivich "With Age comes Wisdom. Although more often, Age travels alone."

Larry Jaques fired this volley in news: snipped-for-privacy@4ax.com:

It's not illegal to sell incandescents, and it's not even illegal to sell

Let me ask you -- WHICH CFL or LED lamp will you be putting in your oven light fixture tonight? Will you still make pizza after that?

LLoyd

Mikie fired this volley in news: snipped-for-privacy@4ax.com:

Why don't you just put a negative-temperature-coefficient inrush limiter resistor in series with each socket? That'll increase the life of the bulbs four or five fold.

Here's a description of them:

LLoyd

I thought the Libruls got rid of the inefficient, heat-causing incans altogether. GlobularSwarming 'n all that, y'know.

In a nice, cost-efficient rental storage space, of course, Pete. You'll pay -only- $400 or so per year for the privilege. Millions of bright Americans do it, so you can't go wrong.

Ooh, now there is a place you require a severe-duty bulb. I wouldn't want to smell a CFL or LED in that position, please.

Luckily, I don't make pizza. Tomato allergy.

Yes, I remember the little blue discs from the '70s and '80s. They fit between the light bulb and socket. I'm not sure I remember any extended lifetimes as a result, but I used some for awhile.

Hide them under your bed. If you hide enough stuff there, you won't have any lazy liberals hiding themselves there. :)

"Michael A. Terrell" on Wed, 08 Jan 2014

I already have a bunch of stuff under there. I'm already putting the bed up on blocks ... and I've a cat who hides down in the "gaps".

-- pyotr filipivich "With Age comes Wisdom. Although more often, Age travels alone."

Larry Jaques on Wed, 08 Jan 2014

I had a storage unit for a while. I bought a house, it was cheaper. It was buy a house or hold a rummage sale.

-- pyotr filipivich "With Age comes Wisdom. Although more often, Age travels alone."

I'm thinking about building a 'Captain's Bed' type base to hold my hospital bed. The cables that adjust the height are broken, and it sits too low to make it easy to stand up, when getting up.

Har! I've always thought home ownership was the far better option, too. The first was rent-to-own. Pre-Prop-13 homes in CA were dirt cheap. Mine was $23,100 in '76.

Be daring: try doing BOTH! I'm lighter better than $2,300 worth from last year's sales, and it's easier and nicer to carry that kind of weight in my wallet, knowwhatImean,Vern?

How so? Any significant increase in life would only be due to the hot resistance of the limiter reducing the lamp's operating voltage, i.e, a plain resistor would do much the same thing.

The cause of the high inrush:

jsw

Bob Engelhardt sent me an email questioning this. My understanding is that the filament thins unevenly as it ages, recrystallizes and evaporates. Thin areas become localized hot spots at startup. jsw

But incandescents' life is limited by evaporation of the tungsten and thinning of the filament, which leads to hot spots which increase the evaproation in the thinned area, and so on. If the surge at turn-on kills a lamp, it was likely very close to end of life anyway.

That Wikipedia article discusses evaporation.

I spent several years working on filament winding equipment and tooling for expensive low-volume lamps, and dinging or otherwise thinning the wire was a big no-no.

The evaporation and recrystallization are not really related, except that both are a result of the operating temperature of the filament. The sintered tungsten bars that are the starting point for the swaging and wire drawing operations are comprised of very large crystals. If you break a TIG electrode you can see the wood-like grain that results when the big grains are distorted and stretched in swaging/rolling/drawing the material. Those big crystals are formed in a relatively short time in sintering, on the order of an hour or two. The bars are sintered by passing a huge current thru them in a hydrogen atmosphere - the sintering temperature is not too different from the operating temp of a lamp filament, around 2600C, IIRC. Imagine a light bulb with a solid filament as big around as your thumb and 2 feet long.

I'm sure the recrystallization of a normal filament happens very quickly as well.

A TIG electrode tip can become brittle enough to knock off cleanly with a hammer in the few seconds it takes me to realize I didn't reopen the cylinder valve after taking a break. jsw