Is Argon an insulator or a conductor?

Date 07-02-2012 14:59

I'm with you on this.

Argon is inert. The electron shells are full, so there is no need for Argon to share electrons, i.e., be conductive.

However, when a votage is applied, it must be sufficient to strip an electron from the outermost shell, i.e., the gas is ionized and thus capable of conducting current. If the voltage drops below the ionization potential, the electron isn't kicked out of the orbit and the gas is once again inert and nonconductive.

Best regards - Al

By rlitman (***)

Date 07-02-2012 15:08

It is all a matter of context.
In a lightbulb, it is a thermal insulator. Heat lost from the filament reduces the efficiency of the bulb.
It is also an electrical insulator, but only in so much as that you wouldn't immerse electrical parts in a conductor.
Once ionized it becomes a plasma. As a plasma, it is free to pass around electrons in a similar way that metals do, making it conductive.

By G.S.Crisi (****)

Date 07-03-2012 19:10

Just a curious comment.
Here in Brazil light bulbs have been recently prohibited because their efficiency is very low (about 5%). This means that they use only 5% of the electric power they consume, the other 95% is wasted as heat.
As a matter of fact, only General Electric was still making light bulbs when the prohibition was approved, and this because of loyalty to their founder. In fact, General Electric was founded by a gentleman called Thomas Alva Edison.
Giovanni S. Crisi
Sao Paulo - Brazil

By OBEWAN

Date 07-03-2012 20:15

Yes, and Edison only had a Jr High School education. And he founded GE! Go figure. He famously once said, "Why should I learn Calculus if I can hire a mathematician?"

By DaveBoyer (*****)

Date 07-04-2012 03:47

Earlier this year filament bulbs over 60 watts became illegal to sell in the US.

I think the jumped the gun on this, as the common replacement is supposed to be the compact flouressent, which has it's own problems. I think LED is probably a better solution, but not fully developed yet.

By 803056

Date 07-04-2012 04:39

I believe they put a stay on that law. For once our legislatures actually listened to the public outcry.

Al

By rlitman (***)

Date 07-07-2012 00:41

Not exactly. First, the bulbs to be phased out were to be removed in this order, 100W, 75W, 60W, and 40W, with the phase out spaced over three years.
For now, the 100W phaseout was postponed from Jan 2012, to Oct 2012. I do not believe it was completely cancelled.

Personally, I'm a little disappointed by the order, not the phaseout itself.
LED replacements for 40W bulbs have now become affordable, and give truly excellent light.
The price on LED 60W replacements has just recently come down from the stratosphere, and 75W LED bulbs are still crazy expensive.
Worst of all, there is no LED drop in replacement for 100W bulbs, and those are going to be the first to be phased out.

By 803056

Date 07-07-2012 02:54

I have yet to see an LED or one of those mini-fluorescent tubes that worth a damn. However, I'll take your word for it. I'll keep looking.

I told my wife to buy extra bulbs every week. They should last as long as I expect to live.

That being said, what my uncle told me still haunts me. "If I knew I was going to live this long, I would have taken better care of myself."

Scary stuff.

Al

By rlitman (***)

Date 07-07-2012 16:09

I have a bunch of fluorescent pigtails. Yeah, they pretty much all suck, in one way or another.
Some of the better ones have improved in the issue of "warmup", but the color rendition is still awful.

The Phillips bulbs with the three yellow panels (they look like something from Star Trek TNG), are actually excellent. They just look funny, so I don't have them installed in my fan light fixtures where the bulb is visible. In my dining room chandelier with frosted glass cups, I replaced nine 60W bulbs with these. The light is just as good as before. Although the shadow of the gaps between the yellow panels appears as a dark line on the frosted glass, the room is very evenly lit.
They are completely dimmable, and unlike incandescent bulbs that turn horribly orange as they dim, these stay the same color, so when fully dimmed, you have a moonlight like effect.

Before these, the yellow phosphorescent material used for white LED lights was directly on the LED component (that's the tiny yellow square you see in most white light LEDs).
My experience has been that while the LED electronics may indeed last for a long time, the color starts to degrade, and I suspect it is because of the amount of light and heat that the phosphor is exposed to. By moving the phosphor to a remote panel as Phillips has done, I am guessing that the color will stay excellent over a longer period of time.

As for the price. The 60W equivalents came to market at close to $50, and spent a long time at $40 each.
About 6 months ago the local power company made a deal with the box stores that they would pay $20 towards the sale of each energy star bulb that the put on a list.
The price then dropped to $35, which became $15 at the register (actually, it was listed at $15 on the shelves even, as the deal is a little "behind the scenes").
For $15, you're not talking much more than a dimmable fluorescent bulb, so I decided it was time to jump.
The 60W equivalent bulb is 12.5W, but I believe the next generation version (which should be out later this year, and was the actual "L Prize bulb") is 10.5W.

The other LED bulbs I've had great experiences with have been from Feit. They make a bulb for 6" hi-hats that replaces the bulb AND the trim ring (this way there is no unsightly heat sink visible, as the new white painted trim ring actually handles the heat dissipation). I believe they're $45 at HD, but again, because of the local power company, they're $25 on the shelves by me. I replaced all four bulbs in my kitchen, and the light is again just as good as it was from 65W incandescent reflector bulbs, but at only 10.5W, plus the bonus of not going orange as they dim.