UV NE-2s?

[star882]

Why there aren't any UV NE-2s?
I see that you can replace the green coating in a green neon with a blacklight coating, or no coating for a germicidal NE-2.

 

[luxO]

"Why there aren't any UV NE-2s?"

Because neon plasma doesn't produce much UV.

"I see that you can replace the green coating in a green neon with a blacklight coating, "

Where do you see this? There is no 'blacklight coating'. The blue/violet glass (called woods glass) used in UV fluorescent tubes is used to filter out the harmfull UV radiation. It doesn't produce UV.

 

[INRETECH]

And the glass would stop any Short Wave UV

If you are looking for Short-WaveUV, get yourself a germicidal FL Tube, they are made out of Quartz to allow the shortwave UV to pass

I used to build a lot of these to erase EProms

Again, the normal care must be taken - since ShortWave UV is bad for the skin and eyes

Mike
www.inretech.com

 

[star882]

On this site http://www.howstuffworks.com/black-light1.htm
"A tube black light is a basically a fluorescent lamp with a different sort of phosphor coating. This coating absorbs harmful shortwave UV-B and UV-C light and emits UV-A light (in the same basic way the phosphor in a fluorescent lamp absorbs UV light and emits visible light). The "black" glass tube itself blocks most visible light, so in the end only benign long-wave UV-A light and some blue and violet visible light pass through."
And on this site http://misty.com/people/don/oddbulb.html
"One version of this is the NE-2G, which is about the size of an NE-2H lamp, about 3/4 inch (19 mm.) long by about a quarter inch (6.3 mm.) in diameter. It is filled with a mixture of neon and xenon gases. Since the excited states of xenon have lower energy levels than those of neon, almost no neon atoms are excited. The glow discharge radiates almost entirely xenon radiation, including a very short wavelength UV that excites the green-glowing phosphor."
So replace the coating in a green neon with the coating used in blacklights, and you get a blacklight NE-2.

 

[Don Klipstein Jr.]

Yes, those green and white "NE-2" style lamps will work somewhat in a blacklight version. They do indeed have a neon-xenon mixture that emits very short wave UV that excites the phosphor.

A major manufacturer is JKL Lamps, http://www.jkllamps.com. They also make miniature cold cathode fluorescent lamps and 12V electronic ballasts (inverters) for them. Among their cold cathode fluorescents, they have blacklight ones in 1 inch and 2 inch by .1 inch diameter, and other sizes. I believe you can get some of these from All Electronics (http://www.allelectronics.com), DigiKey (http://www.digikey.com), and maybe Jameco (http://www.jameco.com).

If someone was willing to buy enough to justify a production run, they could make NE2 style
blacklights.

- Don Klipstein ([email protected]), http://www.misty.com/~don/index.html

 

[INRETECH]

It would be far easier to use some of the 395nm LEDs out there than to bother with the high voltages and other chars. of a Neon Bulb

Mike
www.inretech.com

 

[Tomas]

Just as info, back in the '60's I recall argon lamps in the same form and size as the NE-2's that produced short UV radiation.

There was also a standard (edison) based G-10 argon lamp used for germicidal purposes. Both of these appeared in the old Allied Radio (100 Western Ave., Chicago) catalogs, and I actually had one of the G-10's that was tossed when an old church kitchen was remodeled . . .

 

[INRETECH]

I remember green coated neon bulbs, but they were not very bright

I remember seeing a article in a science book about running one of those edison base neon bulbs connected to ONE door-bell battery and thinking "whats wrong with this picture ?"

I also remember how many times in electronics class when my fellow classmates would try powering up the neon bulb WITHOUT the ballast resistor

Here is a weird piece of trivia, the "negative" resistance in a neon bulb is caused by the LIGHT that it makes making the neon gas inside conduct at a lower voltage

You can test this by biasing a neon bulb SLIGHTLY below its firing voltage, and then shining a light on the tube, it will fire - I have heard of applications that used neon bulbs as gamma-ray detectors