Blue LED Necklace, retail $(Unknown)
Manufactured by (That's unknown too)
Last updated 10-28-11

This is a rather interesting piece of jewelery; although it resembles an ordinary inexpensive necklace, this necklace has a reasonably bright blue LED where you would find the pendant on an ordinary necklace.

It operates from three button cells in the rear clasp assembly, and it has an unexpectedly low current drain of just 2mA, so those tiny button cells should actually last for a respectable time before they poop out.


Put this necklace on as you would put many other necklaces on - that is, unclasp it from the back, put it 'round your neck, and bring the two pieces of the clasp together. Magnets inside each piece of the clasp will do the rest. If the necklace turns on at this point and you don't want it on, just grasp one side of the clasp with each hand and give it a gentle twist until you feel the two pieces seperate and then go back together.

To turn it on, grasp one side of the clasp with each hand and give it a gentle twist until you feel the two pieces seperate and then go back together.
To turn it off, just do the exact same thing.

This appears to be a disposable product, so I do not have to tell you which part to remove, kick down the stairs with all those hungry, hungry piss ants or throw into an open-pit gadolinium mine and then rather emphatically tell you not to.

Due to the way the product was constructed, even though it is disposable, I was able to perform a current usage measurement.
Measures just 2.0mA on my DMM's 400mA scale.

The blue LED necklace is designed to be used as a piece of jewelry, not as a flashlight meant to be carried around, thrashed, trashed, and abused, so I won't try to drown it in the toliet tank, bash it against a steel rod or against the concrete floor of a garage, let my housemate's citty kats go to the litterbox on it, run over it with a 450lb Celebrity motorised wheelchair, stomp on it, use a large claw hammer in order to bash it open to check it for candiosity, fire it from the cannoņata, drop it down the top of Mt. Erupto (I guess I've been watching the TV program "Viva Piņata" too much again - candiosity is usually checked with a laser-type device on a platform with a large readout (located at Piņata Central), with a handheld wand that Langston Lickatoad uses, or with a pack-of-cards-sized device that Fergy Fudgehog uses; the cannoņata (also located at Piņata Central) is only used to shoot piņatas to piņata parties away from picturesque Piņata Island, and Mt. Erupto is an active volcano on Piņata Island), send it to the Daystrom Institute for additional analysis, or perform other indecencies on it that flashlights might have to have performed on them. So this section of the web page about this necklace will be ***SIGNIFICANTLY*** more bare than this section of the web page on a page about a flashlight that was born to be a flashlight and nothing but a flashlight.

The LED in this necklace is bright enough to be used as an emergency flashlight for short-range tasks like searching for that pesky deodouriser cap that rolled behind the water closet or for finding a keyhole, but it was not specifically meant to be used as a flashlight.

Photograph showing the necklace in use.

Spectrographic analysis
Spectrographic analysis of the LED in this necklace.

Spectrographic analysis
Same as above; newer software & settings used.

Spectrographic analysis
Same as above; yet newer software & settings used.

Spectrographic analysis
Spectrographic analysis of the LED in this necklace; spectrometer's response narrowed to a band between 430nm and 490nm to pinpoint peak wavelength, which is ~465.60nm.
USB2000 spectrometer graciously donated by P.L.

My sister found this somewhere in our old apartment on 07-28-08 while we were moving out.
It is not known when the product was received or even who it originally belonged to.

UPDATE: 11-02-09
I received an email; most of the contents of which are as follows (the person's name & email address have been omitted to help protect their privacy:

I recognize that Blue LED necklace. It’s broken :P There is usually a clear (for the blue LED) or colored plastic figurine glued into it. Either a dragon, tiger or dolphin about 1 to 1-1/4 inches long.

I also have the companion piece that’s the same figurine and LED mounted on a car cigarette lighter base (a dragon) that I changed from Green to a UV LED, which causes the figurine to glow a spectral electric blue :)

You can get them for anywhere from $4 to $7 at most drug stores.

Reasonably bright
Unexpectedly low current drain

Disposable - there goes star #5.

    PRODUCT TYPE: LED-lighted necklace
    LAMP TYPE: 3mm blue LED
    No. OF LAMPS: 1
    BEAM TYPE: Narrow directional flood
    SWITCH TYPE: Necklace clasp position-type on/off
    CASE MATERIAL: Plastic
    BEZEL: Plastic; LED inset into hosel for it
    BATTERY: 3x unknown-type button cells
    WATER- AND PEE-RESISTANT: Light splatter- and perspiration-resistant at maximum
    ACCESSORIES: 3x button cells (batteries)
    WARRANTY: Unknown


    Star Rating

Blue LED Necklace *

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