(Received and tested on 11-14-03)
I bought this light bulb from the Americana Resources website a couple of weeks back, simply because it was different enough from the Halloween-themed bulbs you see below.
Instead of pumpkins, witches, goblins, and skulls; this phosphored neon figural has a Christmas tree inside. The tree itself glows green, and the outer perimeter of the tree and the five holes in it glow a kind of pinkish orange.
The green glow comes from a phosphor (a whitish powder or paint) applied to the outer surface of the tree-shaped electrodes. It looks whitish when the bulb is off, and glows green when the bulb is on. The neon gas fill in this bulb probably has krypton or maybe even xenon gas added, so the shortwave UV from this gas can strike the phosphor and make it glow green.
"Scary Silhouette" Figural Neon Bulb, various novelty stores, probably $1 to $3.
(Received in early 07-03, tested around 09-01-03)
A fan of this website sent me some stuff in early July 2003, and several of these neon figural bulbs were among them.
They're made by an unknown Chinese manufacturer for Tony USA, and can be found in various novelty stores.
Two of the boxes are marked "Scary Silhouette", "Great For Parties" and "For Scary Effects". Scary, if you're afraid of light bulbs maybe. :-)
The third box is marked "Happy Holidays Silhouette" and "Festive Lighting Effect". The bulb in it looks "scarier" than the other two. This bulb glows a salmon color, with a very slight violetish tint that you can really only see if you view the electrodes edge-on (from the side) while the bulb is lighted. It probably uses the Penning gas mixture (99.5% neon, 0.5% argon), but has no phosphor on its electrodes, so there is no green color to it.
All three of these bulbs are Halloween themed, and feature electrodes that look like goblins and a pumpkin.
The box claims the bulb draws 3 watts at 120 volts AC. This is a realistic figure given the size of the electrodes inside and the probable gas fill, which is neon and krypton or neon and xenon for the green-glowing models and neon & argon for the orange glowing models.
The slightly pinkish orange glow can be seen coming from between the electrodes, and a green glow can be seen coming from the outsides of the electrodes themselves. The green glow comes from a phosphor (a whitish powder or paint) applied to the outer surface of the electrodes. It looks whitish when the bulb is off, and glows green when the bulb is on. The neon gas fill in this bulb probably has krypton or maybe even xenon gas added, so the shortwave UV from this gas can strike the phosphor and make it glow green.
I should thank Scott T. of Kentucky for these.
Thanks, Scott!!!
G.E. model AR-1 argon glow lamp, General Electric, probably no longer made.
This is an example of an argon glow lamp, made by General Electric. It has a pair of half-moon shaped electrodes inside which glow with a ghostly purple color
when energized. A ballast resistor sealed inside the stem press allows the bulb to be screwed directly into a 115 volt receptacle.
This picture shows the lamp glowing in a rusted out safety socket. :)
And this is what happens when you set the bare bulb next to a source of high frequency, high voltage AC (such as from a nearby plasma globe) and then reach for it.
The discharge column (the glow occurring in the free space between the electrode pair and the very top of the bulb glass where my finger rests) actually has a purplish dark salmon color to it, not the pure argon purple
as this picture shows.
One sad thing about this bulb is that it has a terribly short operating life; typically around 1,000 hours when operating "normally" in an ordinary light socket. This is caused by the glow being driven too strongly - the current
being jacked up above toleranace to achieve a good light output. When the current is too high, it iniates something called "abnormal glow".
This means that very bad things start to happen inside the bulb as a result; one of them is "sputtering" - metal atoms being violently torn off the electrodes by collisions
with high speed charged argon atoms (positive ions) and eventually blackening the glass inside the bulb. Contamination of the argon gas fill by electrode material could be another failure mechanism, or just something that compounds
the original sputtering problem. To make these uncommon and difficult to find bulbs last longer, you can insert a 2K to 3K resistor in series with the bulb when running at
110-120 VAC. This should allow for almost complete coverage of the electrodes by the argon glow, yet possibly extend the lamp life 8-10 times by reducing
the effects of sputtering.
The AR-1 is rated at 105-125VAC at 2.5 watts.
When used on DC, only one electrode will glow.
Spectrographic analysis of the GE AR-1 bulb.
Spectrographic analysis of the GE AR-1 argon glow bulb; using new software & settings.
Spectrographic analysis of the GE AR-1 argon glow bulb; using new software & settings.
Deliberately "overexposed" to show weaker spectral lines.
Spectrographic analysis of the GE AR-1 argon glow bulb; showing UV spectral features.
Spectrographic analysis of the GE AR-1 argon glow bulb; showing NIR spectral features.
This cool looking bulb showed up in the mail, sent by a fan of the website. It is my first so-called "figural" bulb.
No, actually this is my second... my first one (purple flower/green leaves) got busted when I moved in 1996.
Instead of a filament, this bulb has a pair of flat electrodes with an open space between the two. In this case, they're shaped like Halloween Jack-O-Lanterns.
The bulb has neon gas at a low pressure, so the electrodes glow with that characteristic "neon orange nightlight color" which is just right
for a Halloween pumpkin.
Here you can see the bulb glowing. The neon fill is probably the classic "Penning mixture" of 99.5% neon and 0.5% argon. This particular
mixture is used in 110V neon lamps because it ionizes more easily than straight neon.
The lamp is rated for 110V at 3 watts, which is quite typical for neon figurals.
A hearty thanks goes to Roger H. for sending this cool bulb, and just in time for my birthday too. :-)
